What did you do to your Reatta today? <ongoing thread>

[DAVES89]

Glad you caught up on the mice and sorry about the water pump. Interesting upgrade on the radio module, but as you are smart with electronics that is a good upgrade and another example of what you do best. But for guys like myself who are not as gifted electronically I suggest a Kicker "Powered Amp". It is an easy wire in as you only have to tap into the rear speakers, power lead and ground. Is a great addition to our sound system as it adds a fair amount of base. They are available at Walmart, Amazon, as well as Ebay. I bought extra wire harness's for each of my cars and when I switch cars and want the amp I just unplug and move it from car to car. Very convienant.

[ChrisWhewell]

8 hours ago, KDirk said:

 ..........This is getting to be too much work though.....

 

 

 

Yeah, I hear ya.  I sold my vette last week, and a 93 cutlass yesterday.   I feel like a free man again, not chained to these machines !!   Next to go is the HD Road King.  Its a good thing you got the rodents out before they had a piss party

[Guest HuevosRanchero]

finished the rebuild on the drivers side headlamp (new crank, screws,nuts and missing bits)  Put all the nose covers for the first time since ownership (all of it was in the trunk when I bought the car). Going to pick up the new engine shock today (Old one can be twisted around a 1/4 inch at least)

[KDirk]

On my external amp setup I ran a lead for the main power direct to the fuse block and grounded to one of the mounting studs for the center console. Picked up an ignition switched 12v line for the remote power actuation lead on the amp I have the power and CRTC interface leads connected to my modified RIM module, the speaker plugs are routed to a harness adapter which is spliced to the speaker harness that came with the Clarion amp. Used low level (RCA jack) inputs on the amp connected to RCA preouts I installed on the RIM module.

 

Since I had already put 6x9's in the rear speaker locations. (versus the 6.5" component speaker setup that was stock on 88's) it has a nice punch to it now, better than a stock amp even in perfect working condition.

 

I'm lucky I found the mice when I did or they'd have stunk the place up for sure. I just hope I got them all. at least there is no chew damage evident save for a small amount of the foam liner on the inside of the passenger side hush panel. These little fart knockers are a big problem. Had them take up in my convertible engine bay last winter and chewed two wires of the ICM harness. That was a nasty repair. Anyone have suggestions for a passive anti-rodent defense system?

 

 

[dship]

I keep both my Buicks in a 10X36 vinyl igloo.  I place about a dozen cat/dog food cans filled with moth balls under and around the vehicles.  I don't put any inside the vehicles since I cannot stand the smell while driving.  This seems to be the most successful solution for me.  I've tried the Irish Spring soap, dryer sheets, Decon pellets, etc. methods but without much luck until I went the moth ball route.

[KDirk]

Thanks. I knew mothballs were a go to solution, but didn't want to keep them inside due to the odor. Will get some disposable containers and fill them up to place under the car and in the engine bay, hopefully this will help. May do dryer sheets inside as they help keep the car smelling fresh.

 

While a neutral (no odor) smell is my preference for inside the vehicle, my scrub 88 has a residual odor in the dash vents (and maybe the air box that I've not been able to eliminate. Just kind of musty, and is most noticeable with the air or heat on. Probably need to pull the dash, clean the inside of the plenum and the air box (and the condenser coils as well) and that will do it. Probably won't have time for that until spring now. 

[Dashmaster]

Last weekend finally installed the Trans cooler using the same parts and process that Ronnie used.

This weekend cleaned the Intake using Ronnie"s process. Thanks Ronnie for all the great write ups!!!

 

Hopefully my car will stay running good enough the attend the upcoming cars shows I am registered for.

I did take a series of pictures that show 88 only visible features to put in the book I take to shows, I try to educate as many as I can about Reatta's. I also saw a 90 convertible 37K Miles, Red/Tan/Tan on the Mecum Auctions Chicago sell for $10K. Illinois Tag shown was PEPI 90, not sure if this is a forum members car or not. 

[ChrisWhewell]

Woo hoo, my cruise control works.   Not that I'll use it much, but just knowing it works is good enough for me.   Man o man, I sure did a lot on this car, list above.   But no codes now and everything works.   I need to find someone to do the headiner, then get the rear struts changed out, and I think I'm done.   Oh, fuel filter is in order, I can hardly wait to take a gasoline shower.

[DAVES89]

Good/bad week for the Red. Installed the new steering wheel [looks good and I like it] but a developing problem got worse. It started with a front wheel bearing going from a minor problem to a "deal with me now" problem. I had a shimmy as well and later this week a grinding noise.  Stopped at my alignment shop and they said I had a bad front tire which I replaced with two tires. They didn't check further and I thought maybe that is what caused the shimmy. I then thought maybe the wheel bearing [driver front] so I replaced that. That took away the bearing noise but I still had the grinding noise so this morning I did the rear brake pads. The driver side pads were worn down to the backing plate and the passenger side was hardly worn at all. These are reconditioned Cadillac rear calipers that I purchased as part of the rear brake upgrade to get away from the Reatta rear brake rattle. I have now put on over 50 miles at all speeds and the shimmy is gone as is the grinding noise.  The car drives smooth with no noises so for now I am happy, however  I am taking the car over to my mechanic friend to check out why the passenger side rear caliper is not working as it should and why it took replacing the driver's side pads to take away the shimmy.

Edited October 22, 2016 by DAVES89 (see edit history)

[DAVES89]

The belt was separating. They had it on the balancing machine and spun the wheel for me. I saw it for myself. They didn't check further as I didn't ask them to as I thought that the tire separation was the reason for the shimmy and I had to get down the road for an appointment with a client. I knew I could do the wheel bearing and the rear brakes, what I didn't anticipate was the one caliper not working.

 I bought the calipers a cople of years ago as close outs from Rock Auto. As these are original rear hoses I am thinking that will be the issue. I did the front hoses this spring and should have done the rear ones as well.

Edited October 22, 2016 by DAVES89 (see edit history)

[Ronnie]

3 hours ago, DAVES89 said:

this morning I did the rear brake pads. The driver side pads were worn down to the backing plate and the passenger side was hardly worn at all.

 

Dave, my Blazer did about the same thing. The problem was the bolts the caliper slides on were dry and corroded preventing the caliper from staying centered on the rotor. New bolts and a little brake grease cured the problem. Did you check those bolts when you replaced the pads?

[DAVES89]

These calipers only have one bolt as they are the "flip up" style. I removed the bolt on each side but neglected to grease them. I will correct that.

[DAVES89]

OK back to my calipers. The passenger reman rear caliper was working as it should. We took it apart put new pads in it and greased both pins, the screw in pin and the slide pin encased in rubber boots [remember these are "flip up" calipers. Back to the driver's side. My buddy pulled that caliper to check my work and to grease the pins on this side. When he tried flipping the caliper back down over the pads, it fought him. He knew this wasn't right so he looked at the "flip up" part of the caliper a little closer and determined that the rubber encased pin didn't go into the slide correctly. As I had intended to do both the 'vert and the Red rear brakes when the stock rears started to rattle I had purchased 4 each of the reman loaded rear calipers, so on went one replacement [that was for the 'vert] and now all is good. Brakes work as they should, no binding and everything is greased up.

 All that is left is to wait for another "close out" at Amazon, Ebay, or Rock Auto as I need one more caliper to make a pair for when I do the 'vert.

 I bought these for about $35.00 each delivered with no core charge on a recomendation from Mc_Reatta about 2 years ago.

 BTW I never had "Rear brake rattle" on the Red. It was the rear sway bar bushing that made me think I did so that is what made me think I needed to swap them out. That's OK as now I have plenty of back up rear brake parts for the Black should I ever need them.

[DAVES89]

I went to Gibson's yesterday to get some parts for my son in laws 2007 Impala. My daughter had an accident bad enough to deploy the steering wheel air bag [No one was hurt]. What I found out today was that these newer cars once the air bag is deployed "break" the seat belt retractor as well as the air bag module. So what a guy has to do is replace both front seat belts, steering wheel air bag/pad, and the air bag module. There are specific air bag modules to a certain GM car. It is not a one module fits all situation. 

 Our cars are so much simpler that way. We can into an accident, repair the car and off we go.

 BTW I got all the parts for $80.00 One of the places on line wanted $450.00 Another yard, a full service yard I sometimes use was about $200.00 for the same listing of parts.. 

 

[heygibb]

Hello everyone. I bought a new Standard oil pressure unit trying to solve a starting issue I am having on my '90 coupe. I installed it and still could not get car to start. W/out proper signalling from that sensor, I believe the fuel pump will not do its job, as I get no fuel pressure at rail.

So, I bench tested the oil sender, using a method I saw online. Here is the link:

 

It failed the test. I guess what I am wondering is 1-have any of you bench tested the oil sensor using this method? and 2- is it unusual to have a new unit fail out of the box? I bench tested the original unit and it failed, also.

I hope this posts ok. I don't think I have ever embedded a YT vid before. Thanks for your input.

Tim

 

[Ronnie]

I don't believe the oil pressure sensor will keep the engine from running.  I just went out to the garage, disconnected my oil pressure sender, and then started the engine. It started up and ran just fine. Oil pressure was reading 225 psi.

 

Will the engine keep running if you apply 12 volts to the prime/test connector before you start the engine? Connecting 12 volts to the green connector will keep the fuel pump running until you disconnect it.

 

[heygibb]

13 minutes ago, Ronnie said:

I don't believe the oil pressure sensor will keep the engine from running.  I just went out to the garage, disconnected my oil pressure sender, and then started the engine. It started up and ran just fine. Oil pressure was reading 225 psi.

 

Will the engine keep running if you apply 12 volts to the prime/test connector before you start the engine? Connecting 12 volts to the green connector will keep the fuel pump running until you disconnect it.

 

Thanks for the quick reply Ronnie. I checked the prime circuit previously to make sure it wasn't my fuel pump and it works. I get pressure at the rail. I did not try to start the engine in that configuration though. I'll go out and try.

 

[Ronnie]

Have you checked to see if you are getting spark? I may have asked this before, sorry if I did.

[heygibb]

2 minutes ago, Ronnie said:

Have you checked to see if you are getting spark? I may have asked this before, sorry if I did.

I just cranked it w/ the fuel circuit bypassed by the primer terminal. The engine ran but made noises I haven't heard before.

To put all this in context, I replaced the balancer just prior to this. The engine cranked and ran fine several times during an afternoon in the shop. So I know the crank postition sensor was not damaged or moved during that r and r. Prior to dropping car off jackstands, I tried troubleshooting a faulty readout on my ICP of the oil pressure, to determine if it was the gauge or the oil sender. While doing that test, I shorted something and the car would not start back up. I found I had blown the CCCI fuse and replaced it. I also checked the fuel pump relay and it was good.

But to answer your question, no, I have not checked spark. I was convinced it was a breaker/relay problem since the engine quit after I blew that fuse. Since it cranked, I'm getting spark.

 

[heygibb]

Here is the schematic I was using to track down possible issue. Everything, other than the oil pressure unit, has been checked to be working. That is why I thought it was the unit itself, being the problem. Ignore question mark re relay...already checked

Edited November 19, 2016 by heygibb
clarification (see edit history)

[heygibb]

Could I have damaged the ECM or BCM when I shorted that circuit during my test of the cluster gauge? I ran OBD and it still provides info of both systems.

[DAVES89]

Do you have an extra Ignition Control Module/coil pack? Just for grins give it a try. I had one go bad and it was a b***h to start and hardly ran and made weird noises. My buddy said "I am on my way over but swap out the ICM while you wait" Bythe time he got there I had it swapped out and the car was running...

[heygibb]

That would definitely be on my list, Dave, but I just replaced the icm and coil packs within the past year. Probably <2000 miles on them. They were new, not salvage parts. The car cranked and idled fine just before the stupid cluster gauge test I did. Unless I damaged those parts by grounding that circuit, I have faith they are still good. Is it possible I damaged them? When I look at the circuit diagram, it is a component to consider. No doubt about it.

[Ronnie]

It could possibly be the ECM. It's hard to say. You really need to know if it is losing fuel pressure or spark or both when it dies or will not start. If it were me I would start by hooking up a fuel pressure gauge to the engine and watch it closely to see if the pressure is low when the engine dies. If it keeps good fuel pressure then you can concentrate on why it is losing spark.

 

Keep in mind that a bad crankshaft position sensor can cause it to lose both spark and fuel pressure. Without a signal from the crankshaft sensor the ECM will not pick up the fuel pump relay after the engine starts AND the ICM will not fire the spark plugs unless it gets a signal from the crankshaft sensor.

[heygibb]

12 minutes ago, Ronnie said:

It could possibly be the ECM. It's hard to say. You really need to know if it is losing fuel pressure or spark or both when it dies or will not start. If it were me I would start by hooking up a fuel pressure gauge to the engine and watch it closely to see if the pressure is low when the engine dies. If it keeps good fuel pressure then you can concentrate on why it is losing spark.

 

Keep in mind that a bad crankshaft position sensor can cause it to lose both spark and fuel pressure. Without a signal from the crankshaft sensor the ECM will not pick up the fuel pump relay after the engine starts AND the ICM will not fire the spark plugs unless it gets a signal from the crankshaft sensor.

There is no pressure w/out using the prime leg of that circuit.  So doing the pressure test won't work. (I'm familiar w/ your diagnostics page.) If I get no fuel, as is, it seems to me it is a failure of an electronic signal somewhere in the circuit. I'm thinking of trying another crankshaft sensor. It's just weird, as the new balancer worked fine, meaning the cps worked fine, before the short. I have another cps. Maybe I'll give it a go tomorrow. One thing that leads to that being the problem is a test I did that is on your site. I connected vom to green prime terminal and grounded other lead, then turn key over to start. According to your test, vom should read 12 v. MIne reads 7v for a split second and then goes to zero.

Edited November 19, 2016 by heygibb
clarification (see edit history)

[Ronnie]

Have you replaced the fuel pump relay? If not it would be a good investment to eliminate it as being the problem.

 

Here is what should happen for the car to start and run from a fuel pressure point of view:

When you turn the key to the run position the ECM should pick up the fuel pump relay for a few seconds to prime the system - and then drop it out. This should happen each time your turn the key off and then to the run position. You should hear the pump run for a few seconds. Do you?

 

Once the engine starts and the ECM gets a signal from the crankshaft senor that the engine is turning it will pick up the fuel pump relay and keep it latched in to power the fuel pump as long as the engine is running.

 

Now here is where the oil pressure circuit comes in... As long as the engine has oil pressure the contacts in the oil pressure sensor bypass the fuel pump relay and power the fuel pump too. It is like a limp  home mode. That brings a question to mind. Have you tried spinning the starter long enough to build engine oil pressure to see if the engine will start? Once the engine builds oil pressure (see your diagram) the oil pressure sensor contacts should supply power to the fuel pump. Try that and see what happens.

 

 

Edited November 19, 2016 by Ronnie (see edit history)

[Ronnie]

1 hour ago, heygibb said:

I just cranked it w/ the fuel circuit bypassed by the primer terminal. The engine ran but made noises I haven't heard before.

BTW, Those noises weren't caused by using the primer terminal.

[heygibb]

2 minutes ago, Ronnie said:

 

Have you replaced the fuel pump relay? If not it would be a good investment to eliminate it as being the problem.

Yes. It clicks every time I try the ignition.

 

Here is what should happen for the car to start and run from a fuel pressure point of view:

When you turn the key to the run position the ECM should pick up the fuel pump relay for a few seconds to prime the system - and then drop it out. This should happen each time your turn the key off and then to the run position. You should hear the pump run for a few seconds. Do you?

It hums like normal but no pressure at rails. The hum is under the hood. At the fuel tank, no activity. From what you are saying, the ECM isn't picking up the signal from the relay, because no fuel is being pumped to the engine. Sound correct?

 

Once the engine starts and the ECM gets a signal from the crankshaft senor that the engine is turning it will pick up the fuel pump relay and keep it latched in to power the fuel pump as long as the engine is running.

The engine doesn't start since it isn't getting fuel. I checked at the rail w/ the Schrader valve. I only get fuel there w/ the green prime terminal activated.

 

Now here is where the oil pressure circuit comes in... As long as the engine has oil pressure the contacts in the oil pressure sensor bypass the fuel pump relay and power the fuel pump too. It is like a limp  home mode. That brings a question to mind. Have you tried spinning the starter long enough to build engine oil pressure to see if the engine will start? Once the engine builds oil pressure (see your diagram) the oil pressure sensor contacts should supply power to the fuel pump. Try that and see what happens.

When trying to start the car, I've held the key over for 5-7 seconds at a time. I didn't do it w/ the intent of building up the oil pressure but I could do it longer, I suppose. This goes back to my first question though. I don't thing the sending unit I bought is working. The bench test says it isn't. So even if I build the pressure p, if the sending unit doesn't do its thing, I'm not sure it will start. I can try it though.

 

 

[heygibb]

1 minute ago, Ronnie said:

BTW, Those noises weren't caused by using the primer terminal.

Thanks for mentioning that. The noises were spread around the engine. The latest noise I am familiar with was the harmonic balancer clank, which was localized. The noises I heard w/ the prime start were other places, and they seemed to be in the upper area of the block. Weird. I cut engine instead of letting it run to find the source. I didn't want to damage anything.

[heygibb]

Would the engine crank at all if the ECM were bad? Since I'm kind of force feeding fuel w/ the green primer terminal, I could see where the ECM is being bypassed and it still cranks. Am I wrong? That would explain it not providing fuel the normal way. Are they still available new?

[Ronnie]

11 minutes ago, heygibb said:

It hums like normal but no pressure at rails.

Is it possible you are hearing the brake pump motor running?

 

12 minutes ago, heygibb said:

From what you are saying, the ECM isn't picking up the signal from the relay, because no fuel is being pumped to the engine. Sound correct?

Well it should start for a second on the pressure that should be built during the ECM prime cycle if it is working right.

 

21 minutes ago, heygibb said:

The engine doesn't start since it isn't getting fuel. I checked at the rail w/ the Schrader valve. I only get fuel there w/ the green prime terminal activated.

That leads me to believe the problem is with the fuel pump relay, the relay power circuit or the ECM not picking up the relay correctly.

 

Quote

Would the engine crank at all if the ECM were bad? Since I'm kind of force feeding fuel w/ the green primer terminal, I could see where the ECM is being bypassed and it still cranks. Am I wrong? That would explain it not providing fuel the normal way. Are they still available new?

The ECM could be the problem. There are a lot of different ways it could fail. They are still available but it is an expensive part. I would rule out everything else first. To be honest I don't really think that is it. The ECM wouldn't cause you to only read 7 volts at the green connector instead of 12. That low voltage is more of a function of the fuel pump relay or the circuit powering the relay. The ECM only picks up the relay. There is a different circuit that provides power to contacts in the relay. Perhaps you should check that circuit to see if 12 volts is getting to the fuel pump relay.

[heygibb]

2 minutes ago, Ronnie said:

Is it possible you are hearing the brake pump motor running?

I was just reading about that hum under the hood. That is what it is.

Well it should start for a second on the pressure that should be built during the ECM prime cycle if it is working right.

Not even close to starting.

That leads me to believe the problem is with the fuel pump relay, the relay power circuit or the ECM not picking up the relay correctly.

I tested and replaced the relay several times. It is located in the interior relay center, RH side of console. It clicks every time I turn the key over. I can try another one, I suppose.

The ECM could be the problem. There are a lot of different ways it could fail. They are still available but it is an expensive part. I would rule out everything else first. To be honest I don't really think that is it. The ECM wouldn't cause you to only read 7 volts at the green connector instead of 12. That low voltage is more of a function of the fuel pump relay or the circuit powering the relay. The ECM only picks up the relay. There is a different circuit that provides power to contacts in the relay. Perhaps you should check that circuit to see if 12 volts is getting to the fuel pump relay.

Is the circuit you speak of the one on the far left in the diagram I posted? If so, I need to check the voltage between the relay and ECM? It is a DRK GRN/WHT wire. That should read 12v coming from relay, w/ key in run position?

I have to check out for hunting trip in AM. Thanks for your interest and help. I do have one thing to check...maybe makes no sense, but I cleared the OBD info prior to starting engine w/ the primer terminal. If I run the OBD again, won't it show some diagnostic info if the ECM is still working? Now that I think about it, there would be no codes on what we are dealing with. I could be wrong about that. I'll check the thread tomorrow afternoon. Tim

 

[Ronnie]

On 11/19/2016 at 0:04 AM, heygibb said:

I tested and replaced the relay several times. It is located in the interior relay center, RH side of console. It clicks every time I turn the key over. I can try another one, I suppose.

You should test the relay at terminal #1 in your diagram to make sure it has 12 volts going into the relay. If it doesn't you could have a bad/dirty fuse connection. Terminal # 1 should have 12 volts when the key is turned to run. Then check terminal #4 on the relay to see if it has 12 volts coming out monetarily when you turn the key to run. If you can hear the relay clicking the ECM is probably doing it's job of momentarily providing a prime shot when you turn the key to run.

 

My fuel pump relay is on the firewall. The testing I talked about would be pretty easy to do. I don't know how to tell you to test the relay on the '90.

 

I wouldn't do any testing on the circuit between the ECM and relay unless you are sure how to do it. (I don't) You might damage  the ECM.  If the ECM is picking up the relay when you turn the key to run it is doing it's job at that point and the engine should build enough fuel pressure to start providing everything else is working properly.

 

As for checking the OBD. a bad crank sensor or ICM won't set a code, nor will low fuel pressure. I would check for codes anyway.

 

 

 

 

Edited November 21, 2016 by Ronnie (see edit history)

[DAVES89]

I had to replace the hub assembly on the Red again as the new one I installed a month ago failed. While I was there I took a close look at my protype reconditioned sensor lead I installed about 45,000 miles ago. What I was doing at the time was just repairing the bad area of the lead using a heat shrink with a shrink ratio of 4-1. So what happened with this lead is that the reconditioned part is holding up well but the original part has cracks and needs to be repaired. It is now in my "needs to be rebuilt" pile of leads.

[heygibb]

17 hours ago, Ronnie said:

You should test the relay at terminal #1 in your diagram to make sure it has 12 volts going into the relay. If it doesn't you could have a bad/dirty fuse connection. Terminal # 1 should have 12 volts all the time. Then check terminal #4 on the relay to see if it has 12 volts coming out monetarily when you turn the key to run. If you can hear the relay clicking the ECM is probably doing it's job of momentarily providing a prime shot when you turn the key to run.

 

My fuel pump relay is on the firewall. The testing I talked about would be pretty easy to do. I don't know how to tell you to test the relay on the '90.

 

I wouldn't do any testing on the circuit between the ECM and relay unless you are sure how to do it. (I don't) You might damage  the ECM.  If the ECM is picking up the relay when you turn the key to run it is doing it's job at that point and the engine should build enough fuel pressure to start providing everything else is working properly.

 

As for checking the OBD. a bad crank sensor or ICM won't set a code, nor will low fuel pressure. I would check for codes though.

It's been a long day. Not much sleep last night and hunting most of the day. I'll follow your suggestions but it will be tomorrow. A thought occurred to me last night in bed. It is kind of a back door approach to the potential of the ECM being the problem. To see if it is working, I think I will disable the EGR and look for an E026 code. There is, also, an ED99 data value that is an indicator whether the proper PROM is installed in the ECM. This info might be stored in memory and not important, but if it is real time info, it might tell me if the ECM data is accessible. The PROM number itself isn't what I'm looking for, just whether it posts or not.

 

I want to post something as a warning to others. It is the diagnostic procedure I tried to use for determining whether the false readout of my cluster gauge was from oil sending unit failure or gauge failure. When I attempted to ground the sending unit via the plug from the harness, I shorted the circuit. It blew my CCCI breaker and caused whatever I'm dealing w/ now. My car purred after the harmonic balancer change out, done just before this. After this procedure, car would not crank except w/ prime fuel terminal. When I grounded the 'wire', I touched the hot leg, evidently instead of the leg going back to IPC. There are four wires in the harness...PNK/BLK (pink /w black stripe), BLK/PNK (black w/ pink stripe), GRY (gray), and GRN (green). The PNK/BLK feeds the ICM. The GRY feeds the fuel pump. The GRN carries 5v from ignition, I believe. ( I am not certain, as the schematic posted before only IDs 2 of the 4 wires.) And my GRN wire carries 2.75v. Both of these voltage readings are w/ the key on run/no start and could be erroneous. I never checked these values prior to this.

Here is the process I copied and pasted from the internet. I couldn't find the direct link. This was in my files.

 

DO NOT TRY THIS AT HOME!!! USE AT YOUR OWN RISK!!!

For vehicles with an oil pressure gauge, the sending unit (located next to the oil filter) is essentially a variable path to ground for the gauge. When the engine is off, the sender is shorted to ground, and the gauge reads "0" psi (or close), as the oil pressure increases, the sender offers resistance to ground, providing a mid scale readings on the gauge. If the wire is removed altogether, the gauge will read off the scale to the high side (3:00 position) all the time. This is a quick and simple test you can perform to help isolate the problem. With the key ON - engine OFF, pull the wire off the sending unit. The gauge should read full scale. Now short the wire to ground (this will not harm anything), and it should read "0". If this is correct, then your gauge, and the wiring is good, and your trouble is likely to be the sending unit. If this test has little or no effect on the gauge, then your problem is in the wiring or the gauge itself.

For vehicles with an indicator light, the sending unit is like a simple switch. When the engine is off, or the pressure is too low, the switch closes, and illuminates the lamp. Under pressure, the switch is open and the lamp goes out. The only difference in the above test, is with the wire disconnected, the light is out, and with the wire grounded, the light is on.

 

[rjfranken]

Tom Payette (buick dealer in Louisville) came out to see my cars for sale. maybe ill get some traction

[heygibb]

I got a chance to do a little more troubleshooting today.  I did get past one issue that occurred Sat. The engine did not shudder, w/ new noises, when started w/ prime circuit for fuel.. It idled normally and cranked every time I tried it.
I ran OBD, both running and engine off. Most data was within normal limits. I did get one error code, B132, which is for oil pressure sender failure. I got this code w/ the sender connector not plugged in. After I plugged in the harness, the code went away.  That is a little confusing since I think the sender is bad. Maybe just being plugged in allows signaling to BCM that it is in place, but not necessarily working right. I don’t know.

ENGINE RUNNING
BD71  Oil psi all over the place between 66-254…probably normal for bad sender
ED17    OLD  PA3 (knock signal) was 451, outside of the 0-255 parameter…I don’t know what it means.
I disconnected EGR connector prior to start but did not get an error code for that like I thought I would.

ENGINE OFF
BD99   BCM Prom ID 9534…should be between 0-9999
ED99   ECM Prom ID 9044…this is high unless my info has typo (0-999)
EO 04  EGR Sol #1   I could hear it energize under the hood…readout lo-hi
EO 05 EGR Sol #2    same
EO 06 EGR Sol #3    same
    These readings are with EGR connected.

I read the voltage at the prime terminal when key turned on to start, I get zero (0) volts. That indicates a bad crank position sensor. Is that possible, if engine cranks w/  fuel assist from prime terminal?

I’ll do some more research online tomorrow.  If the unusual OBD numbers above mean anything to someone, chime in.

Tim

[Ronnie]

10 hours ago, heygibb said:

ED99   ECM Prom ID 9044…this is high unless my info has typo (0-999)

That is the correct ECM Prom ID number for a 1990 model.

 

10 hours ago, heygibb said:

I read the voltage at the prime terminal when key turned on to start, I get zero (0) volts. That indicates a bad crank position sensor. Is that possible, if engine cranks w/  fuel assist from prime terminal?

I'm not sure how you determined that means the crankshaft position sensor is bad. I must be missing something. If the engine is running the crank position sensor has to be working or you wouldn't have a spark. The ICM needs a signal from the crank sensor to know when to fire the spark plugs. No crank sensor signal=No spark. I recommend you go back to my last post and check the circuit in your diagram from the fuse a to the fuel pump relay.  I have highlighted the circuit in red that needs to be tested in the photo below. That circuit is what powers the pump. The ECM only picks up the fuel pump relay to complete the circuit.

 

 

 

Edited November 21, 2016 by Ronnie
fixed typos (see edit history)

[DAVES89]

Listen to Ronnie. This is going to be another series of posts similar to "Snowdrift". 

 I would recommend you start a new post as this one may get long...

[heygibb]

14 hours ago, Ronnie said:

That is the correct ECM Prom ID number for a 1990 model.
 

 

I'm not sure how you determined that means the crankshaft position sensor is bad. I must be missing something. If the engine is running the crank position sensor has to be working or you wouldn't have a spark. The ICM needs a signal from the crank sensor to know when to fire the spark plugs. No crank sensor signal=No spark. I recommend you go back to my last post and check the circuit in your diagram from the fuse a to the fuel pump relay.  I have highlighted the circuit in red that needs to be tested in the photo below. That circuit is what powers the pump. The ECM only picks up the fuel pump relay to complete the circuit.

 

 

 

re ED99 data, I figured the 9044 number was correct. That is why I mentioned a possible typo in my source, found here...

  http://www.reatta.net/diagnostics/diag_ecm_bcm.html   ...third page, under "for ECM data"...parameter 0-999

 

re the crank position sensor issue. In a posting by you in 2014, you indicated the CPS was good if I detected 12v from the prime terminal during cranking. I don't. That is why I made the rhetorical comment Is that possible, if engine cranks w/  fuel assist from prime terminal?...

 

re testing the circuit you mentioned in a previous post, that was next on my list. I didn't spend much time in the garage yesterday. I wanted to focus on the OBD data w/ and w/out the EGR valve connected. I was trying to see if I got an error code, to determine, in a back door way, if the ECM was working. I got no error code w/ it disconnected.

as requested, I will post new thread so it can be followed coherently. I'll list it as "crank/no start"