2seater Posted June 17, 2011 Share Posted June 17, 2011 I returned my car to essentially stock some time ago but have only driven it a few hundred miles since and it has worked flawlessly. I washed the car yesterday and it has decided not to run properly since. No washing was done under the hood, and it was just a quick rinse job. I have traced the bad behavior to this point. If you drop the hood with the engine idling, it will quit immediately. The same thing happens just popping the hood from the closed position. With the hood open and engine running, just a hand slap on the strut brace or either of the front diagonal braces will cause an instant stall also. Wiggling or tapping on the accessible sensors and wiring has no effect, including the MAF. A sharp rap on the engine at various points has no effect and continues to idle smoothly. I doubt it is fuel related as the engine stops immediately, no bumbling and dying, just dead in an instant. I will delve into it deeper after the engine cools and maybe change the knock sensor, as I would have expected a stumble when rapping on the engine. I checked its operation just a week or so ago and it registered on the knock counter normally when tapping the engine. I am sort of stumped as to what connection could be fragile enough to fail under the conditions described? Battery connection or the hot and ground boxes on the right fender? Ideas anyone? Link to comment Share on other sites More sharing options...
padgett Posted June 17, 2011 Share Posted June 17, 2011 Well, you seem to still have a Magnaxox... Link to comment Share on other sites More sharing options...
NCReatta Posted June 17, 2011 Share Posted June 17, 2011 How about is you were to drive it around the yard with he hood closed to the catch point? Does it still stall and stumble? Sounds like a ground to me so far.Is it throwing any codes? Link to comment Share on other sites More sharing options...
Guest Mc_Reatta Posted June 17, 2011 Share Posted June 17, 2011 Doubt the knock sensor has any bearing on this issue.Do check the positive and ground points on the fender, radiator support, and ground connections to the engine. You have repositioned the ICM. There is a ground wire that was connected to that support brace, so make sure it is connected well and the ICM itself has a good ground to the bracket through its bottom.How does the car drive down the road? Link to comment Share on other sites More sharing options...
2seater Posted June 17, 2011 Author Share Posted June 17, 2011 Thanks guys. Yes, the knock sensor seems to be a non-player and registers normally. The only thing I actually did, aside from wiggling everything in sight, was tighten the battery cables. The problem is gone. The connections appeared (felt) tight and clean, however the positive cable is suspect due to internal corrosion. I had removed the red insulator previously to clean it as best possible but not much can be done without physically taking the connections apart, shorten and recrimp/solder, but that doesn't look practical. I checked the resistance of the two accessible connections from the positive terminal and it shows .3 ohms from the battery + to the terminal box on the fender and to the alternator hot connection. While the engine is running, these same connections show in the 20-25 ohm range?? Is this indicative of normal operation or does it point up the high resistance present due to current flow. My gut feeling is that it is not normal and needs to be repaired/replaced? Link to comment Share on other sites More sharing options...
padgett Posted June 17, 2011 Share Posted June 17, 2011 If you are reading resistance when the engine is running, I suspect the voltage drop across the connection is affecting the resistance reading (for resistance the DMM is actually measuring the current imposed by a 1.5v (typ) source. The drop across a resistance caused by the running engine will add to the source voltage.. Link to comment Share on other sites More sharing options...
Guest Richard D Posted June 17, 2011 Share Posted June 17, 2011 The impedence reading while running is due to current flow, normal. Link to comment Share on other sites More sharing options...
Guest Mc_Reatta Posted June 17, 2011 Share Posted June 17, 2011 2seater, I see you have top posts on your battery. You can use these to check the condition of your connections also.I would do it with the engine off. Set your DVM on the 2 volt scale and put one probe on the red positive top post and measure the voltage between it and the battery cable on the side of the battery, the positive post on the fender wall behind the battery, and the battery wire on the alternator. If you get a reading at any location of more than a tenth of a volt or two then there is a problem with the connection of that wire. If you want to go the extra mile you can also measure the wire at the starter solenoid, but that's hard to do without alot more effort. For the negative side, do similar readings but this time use the DVM in the Ohm function set to the 200 ohms scale. Measure between the battery black top post, the negative battery cable on the side, the engine block by the ICM and the negative connection posts on the fender behind the battery and on the radiator support. If you get any reading over an ohm or two, you have a problem with that wire. I too have had problems inside the plastic end caps on the cables. I ended up replacing the bolts that hold the cables to the side posts. You and use a small screwdriver to pry the plastic around the edge back away from the outside of the bolt hole until you can get the edge of the bolt out of the hole and work around the circumference until you can remove the entire bolt. Clean the metal inside the cable end on the front and rear well with a small wire brush or sandpaper etc. and then insert a new battery bolt that you get from your FLAPS that matches the ones you remove in size and length and then use the small screwdriver again to lift the edge of the plastic around the hole back up and over the edge of the bolt head, and word around the edge until the bolt is seated back in place and reinstall the cable onto the battery.If your problem is where the multiple wires join up inside the cover, you probably need to find a new cable and just replace it. Link to comment Share on other sites More sharing options...
DAVES89 Posted June 20, 2011 Share Posted June 20, 2011 2 seater I have avialable [for testing] a top mount clamp converter set up I made up when I had a top mounted Optima battery in my Black. For some reason Optima has moved the posts farther in so I had to make up a different post adapter. I have now removed that battery and installed it in my boat. At any rate I can lend it to you for a period of time if you are interested. PM if interested. or email lemke1044@aol.com Link to comment Share on other sites More sharing options...
2seater Posted June 20, 2011 Author Share Posted June 20, 2011 Thanks everyone, and I appreciate the detailed reply Mc. I do not find a smoking gun in any of the power and ground connections in the area of the battery. I get no voltage drop in any connection on the hot side and no more than a .1-.2 ohms for any negative connection. Of course the problem has disappeared after reseating the battery connections previously, so there may be noting to find. The power to the starter has never been a problem so it may have only been a ground fault as suggested. So far, so good. Thganks all. Link to comment Share on other sites More sharing options...
padgett Posted June 20, 2011 Share Posted June 20, 2011 I use an Optima 25/75 (dual posts) for everything except the scooter and the RV This has the wide terminals and simplifies the spares situation. The 34/78 does have a bit more capacity but does not fit a Fiero and the 25/75 spins the 400 cid RA Pontiac just fine. Link to comment Share on other sites More sharing options...
Guest Mc_Reatta Posted June 20, 2011 Share Posted June 20, 2011 Glad your problem seems to be solved. Probably was a problem with a battery connection. Why it chose to go bad while you were washing the car will remain a mystery I'm sure. Link to comment Share on other sites More sharing options...
raleets Posted June 20, 2011 Share Posted June 20, 2011 "Suspect" electrical connections don't like high humidity, which is normal when washing a car, right?Just sayin',Bob Link to comment Share on other sites More sharing options...
wws944 Posted June 20, 2011 Share Posted June 20, 2011 One little design flaw that I have noticed in the Reatta is that there are no little 'lips' along the fenders to duct water away from the engine compartment. So the battery area on one side, and the relay box on the other can get quite drenched. Buick seems to have discovered this too late in the design process. Their 'workaround' was a plastic water deflector over the spot where the negative wire is connected to the chassis.So I guess one question is if your car has the water deflector? The photo of your engine compartment just barely doesn't show it.One other little detail from this problem is that water can pool on top of the screws that hold the air filter cover on - so they get rusty. Link to comment Share on other sites More sharing options...
2seater Posted June 21, 2011 Author Share Posted June 21, 2011 Interesting observation on the fenders and water deflection. I suspect the lack of vertical flange is due to the composite material used for the fenders. The lack of drip rails on the roof look nice but no fun in the actual rain. Operation is still normal except the service engine light will come on for one to two minutes when started after sitting a while. Of course now is the time the climate control decided to stop operation of the temp. up button so diagnostics could not be accessed. I have repaired this once before and a thorough cleaning of the buttons has restored proper operation again. In any case, I get a code 043, knock sensor, both current and history. I watched the knock indicator when the engine was started and it does indeed show 4 degrees of timing is being pulled and the spark timing indicator confirms the same reduction in timing. The actual knock indicator does not indicate any knock is present and I know it is registering properly. After a short time, a minute or so, the knock retard stops and timing returns to normal. The service engine light goes out as well. I will investigate further but I suspect the Memcal may be at fault. This is the modified memcal with the ZIF socket for chip changes (turbo project) and the only stock programming chip I have fits this socket. Need to find a stock '90 Memcal to eliminate this possible gremlin. Stock program was ANWU. Link to comment Share on other sites More sharing options...
padgett Posted June 21, 2011 Share Posted June 21, 2011 Might be the memcal but I doubt it. Have to understand that the memory chip is made up of data lines and address lines. To get a particular memory, you put in the address and read out the menory. The Memcal also contains the ECM program. To lose just one data point is unlikely. Possible but unlikely. Stuck bits affecting a whole range is more common.Is this just on cold starts or hot starts as well ? Link to comment Share on other sites More sharing options...
2seater Posted June 21, 2011 Author Share Posted June 21, 2011 It does it both cold and hot. Takes a few seconds for it to come on and then approx. one minute to go out. The knock counts do not increment upwards while this is happening but I retested and the sensor does indicate knock when the engine is tapped lightly. The reason I mention the chip is one of the iterations of the turbo programmed chips had an error that did not read knock, so I am guessing there could be an error in the chip. The FSM diagnostic tree also mentions the MEMCAL. I do need to check the sensor and wiring at the sensor for proper voltage and resistance when the engine is cooler. Link to comment Share on other sites More sharing options...
padgett Posted June 21, 2011 Share Posted June 21, 2011 Is this with a stock MemCal or "Something else" ? Link to comment Share on other sites More sharing options...
2seater Posted June 21, 2011 Author Share Posted June 21, 2011 Uh no, it isn't stock, it's something else. It's the actual chip portion of the MEMCAL, mounted in a socket that allows it to be removed and swapped without replacing the entire assembly. It is supposed to be the copy of the stock ANWU. I have several "chips", but all have programming for larger injectors and reduced timing for the turbo installation. I also have a complete memcal, however it is also programmed for the turbo, version 1.0. So I don't have an unmolested memcal to try. Link to comment Share on other sites More sharing options...
DAVES89 Posted June 22, 2011 Share Posted June 22, 2011 I have two BCM's but only one ECM. It is from a 1990 Riv. "APTN" It's yours if you want it... Link to comment Share on other sites More sharing options...
padgett Posted June 22, 2011 Share Posted June 22, 2011 Sounds like it comes on quickly then goes out when the car goes into closed loop. If you are not sure about the programming, that could be it. Link to comment Share on other sites More sharing options...
2seater Posted June 22, 2011 Author Share Posted June 22, 2011 Thanks Dave. Is that the EEPROM, alias MEMCAL, APTN that's available? I did check the wiring and knock sensor. The harness voltage to the connection at the sensor is 4.92 volts, which is correct and the sensor resistance @ 3800 ohms is also correct. The only thing I cannot confirm is the voltage output of the sensor when knocking on the engine. My digital VOM does not show any voltage generated when knocking on the engine. Perhaps it is too slow to respond? I think I have an old analog meter somewhere and I will give that a try. Failing that, I will try a different knock sensor. All tests so far point to a bad "chip". Link to comment Share on other sites More sharing options...
Guest Mc_Reatta Posted June 22, 2011 Share Posted June 22, 2011 Think your barking up the wrong tree with the knock sensor. Your analog meter will not be quick enough to see a knock signal either. Need an O scope, but the diagnostics mode is showing you the sensor is working by logging counts when you tap on the block. Link to comment Share on other sites More sharing options...
DAVES89 Posted June 22, 2011 Share Posted June 22, 2011 Thanks Dave. Is that the EEPROM, alias MEMCAL, APTN that's available? I did check the wiring and knock sensor. The harness voltage to the connection at the sensor is 4.92 volts, which is correct and the sensor resistance @ 3800 ohms is also correct. The only thing I cannot confirm is the voltage output of the sensor when knocking on the engine. My digital VOM does not show any voltage generated when knocking on the engine. Perhaps it is too slow to respond? I think I have an old analog meter somewhere and I will give that a try. Failing that, I will try a different knock sensor. All tests so far point to a bad "chip".2 seater here is what I have. It is a remanufactured Original Equipment unit O.E.# 16198264 Number 7-8253 Calibration Code 1195 The long blue bar inside the ECM says DELCO APTN 2208 Let me know if that would work. I would go to Gibson's for you as there are a number of Riv's there, as well as two Reattas, but with all the rain we got last night it will take at least a week to dry out enough to walk around out there. Link to comment Share on other sites More sharing options...
padgett Posted June 22, 2011 Share Posted June 22, 2011 I show APTN as a 1989 E57 (Riviera) with federal emissions. Of course if has been reprogrammed then all bets are off. Link to comment Share on other sites More sharing options...
DAVES89 Posted June 22, 2011 Share Posted June 22, 2011 I could have sworn it was out of a '90 White/Tan [i got a lot of parts out of that car, she sure was nice to me...] Maybe that is why it didn't run, when it was taken to the yard. At any rate, if you think it will work and you want it, come and get it... Link to comment Share on other sites More sharing options...
2seater Posted June 22, 2011 Author Share Posted June 22, 2011 Mc, I know what you mean about the meters ability to see the signal but the only reason I tried it was the FSM recommends this test. The spare engine w/sensor doesn't show anything either, so I am pretty sure the chip is the problem. It runs perfectly in all other respects.Dave, what a generous offer. I do not have a spare ECM and I have considered getting one for another reason as well. I use it to power MAF sensors to test on the flowbench. I know about Gibby's too. I'm sure it's a mud bath right now. No need for extraordinary meaures yet. Link to comment Share on other sites More sharing options...
padgett Posted June 22, 2011 Share Posted June 22, 2011 Unfortunately all of my good MemCals are in cars now. Jim probably has an ECM with the correct Reatta MemCal. Link to comment Share on other sites More sharing options...
2seater Posted June 26, 2011 Author Share Posted June 26, 2011 I was concerned that I hadn't found any real problem but had suddenly cured itself and I was right to be worried. I drove it to work for the last week and it performed without a hitch (aside from that goofy knock sensor code). Fuel pressure is good also. It decided to hiccup a couple of times @ 70 mph on the way to Green Bay (30 miles) and my sons wedding but otherwise worked normally. After the ceremony it decided it wanted to act up as before. Erratic idle, if it starts, and then will shut off if the hood is closed. It is sitting in the church parking lot and will investigate further tommorrow. I have a replacement ECM and Memcal coming from Mr. Finn. There are only a couple of things that will not set a code when acting up, coil pack/ICM, CPS as well as the ECM itself. It is also possible I have had vermin chewing on something unseen and have not found it yet. Link to comment Share on other sites More sharing options...
Ronnie Posted June 26, 2011 Share Posted June 26, 2011 If it completely quits and will not start you might try the tests on my website.Crank Position Sensor & ICM Troubleshooting*-*ReattaOwner.comYou may know some better tests but it might be a good place to start your search for the problem. Link to comment Share on other sites More sharing options...
padgett Posted June 26, 2011 Share Posted June 26, 2011 What is the tach doing ? Is it stable/woggling when the engine is noggling or does it drop to zero and jump back ? If it zeros while the engine is turning then I'd look to primary ignition (CPS, ICM, ign switch) particularly if the whole display blanks.This really sounds like a wiring issue and could also relate to the ECM firing the injectors (if not rattling, you don't get fuel and the engine won't run (once had a Fiero that kept draining the battery after 2-3 days. Turned out the PO had hardwired the ignition so the ICM-equivalent always had power, engine stopped when turned key off because it stopped getting fuel.)This is where an O'scope is really handy but can hook up a 'noid remotely and monitor the injector fire.Sounds like about the time you need to monitor fuel rail pressure, ignition fire, and injector fire because you are losing one or two of them.If I were a professional, I'd cobble up a test rig to check those three things. Wonder how an electrical oil pressure sender would react to being on the fuel rail - pressure should be pressure. HF fuel pressure gauges always seem to leak but come with all sorts of adapters... Link to comment Share on other sites More sharing options...
Guest Mc_Reatta Posted June 26, 2011 Share Posted June 26, 2011 Impalas and Caprices came with adjustable low pressure cut off switches in their AC systems. If they were tweekable up to 40 psi ish, they would screw right over the Schrader valve on the fuel rail and allow monitoring whether or not the rail gets up to pressure and maintains it with a DVM or trouble light and battery rig. 40 might be higher than the were designed to go, but they may get close enough to get the job done.Someone with a decent Pic and Pay could get one cheap and try it out.If you had to buy one new it would probably be no better than buying a fuel pressure gauge at HF. Link to comment Share on other sites More sharing options...
padgett Posted June 26, 2011 Share Posted June 26, 2011 Sounds like a good idea - might need a right angle or hose to be able to close the hood. BTW when turned off on a hot day the low side a/c can easily equalize at 90-100psi. Could adjust with an air source. Link to comment Share on other sites More sharing options...
2seater Posted June 26, 2011 Author Share Posted June 26, 2011 (edited) Thanks for sticking with me guys. I arranged to have it flatbedded home. I got there ahead of the tow vehicle so, of course, I tried it. Started right up and ran like nothing was wrong. I let it go for 1/2 hour or so and finally shut it off. Nothing I did would cause a stutter. I started it again after a few minutes and I ran though the diagnostics but of course, everything is normal. It ran for about five minutes and then just shut off. The tach drops to zero as the engine stops but no erratic behavior from any gauges. It will now crank but not start. Occasionaly I will get a couple of fires but I think (hope) it will stay broken. It certainly acts like the crank sensor so I will check it out and probably replace. I know I have given the same advice many times but I think some coincidental things have led me down a false path. At least it is home so I can investigate at some leisure.Fuel pressure was 36/44 psi when I checked a couple of days ago but I cannot rule out the fuel pump unless the pressure is still good and won't start. It stops so quickly, my gut says ignition. I can't fiddle with it right now so will check again tommorrow. Edited June 26, 2011 by 2seater (see edit history) Link to comment Share on other sites More sharing options...
Guest Mc_Reatta Posted June 26, 2011 Share Posted June 26, 2011 Think folks that are having these problems should give some serious consideration to building up a tester like Ronnie proposed in his test procedure for the crank sensor and ICM.Anyone handy with electrical stuff could gen up a noid light tester from some parts from radio shack for a few dollars and use some odds and ends from around the house and come up with a light that could test all of the circuits and sensors that make or need a waveform signal. Obviously wouldn't be as nice as an o scope or frequency meter, but not very many of us have or can afford those. Won't tell you if a signal is out of the proper range, but I think most of the time you really just need to know if the signal is there at all or not. That and a fuel pressure tester would make these problems much easier and more accurate to diagnose and pay for themselves with the first part you don't purchase unnecessarily. Link to comment Share on other sites More sharing options...
2seater Posted June 27, 2011 Author Share Posted June 27, 2011 Mc, I couldn't agree more and I intend to do just that. I wonder if the frequency function of my VOM will work for some of what you mention? I use it to test MAF sensors and it works well for that. Mine is definitely not a fuel delivery problem. It started and ran for several minutes with a fuel pressure gauge attached. It did finally die but the fuel pressure remained steady. Actually, it jumped up when the vacuum went away. For some reason, mine will not remain broken. It started and ran normally just now. Testing while in the non-failure mode will likely yield negative results. Link to comment Share on other sites More sharing options...
Guest Mc_Reatta Posted June 27, 2011 Share Posted June 27, 2011 Yes, a VOM or DVM with a frequency function should allow checking for these signals as well. You have also touched on the joy of finding an intermittent fault. Electrical devices can fail many ways. So methods to induce or correct an intermittent fault are employed to try to flush them out. Changing the temperature of the device, wiggling attached wires and connectors, removing and replacing connectors, applying vibration or shock, changing orientation, checking incoming power and grounds etc.If none of those work, you pretty much have to wait for the failure to recur and test it then. Link to comment Share on other sites More sharing options...
Ronnie Posted June 27, 2011 Share Posted June 27, 2011 Yes, a VOM or DVM with a frequency function should allow checking for these signals as well. Darn, I was hoping my crude procedure, intended for those of us with minimum diagnostic tools, was going to br put to the test. Maybe next time. Link to comment Share on other sites More sharing options...
2seater Posted June 27, 2011 Author Share Posted June 27, 2011 Of course it is running normally again, damn. I tried a noid light and that will kill the engine when probed while running. I thought it likely would since it's really only a light bulb. I'm not enough of an electronics whiz to make something that will allow the engine to run and keep an indicator connected. I have a lot of LEDs' and could probably make something with a dropping resistor but it sounds like the Radio Shack assembly is already done and perhaps has enough resistance to not short out the signal wire? Does anyone have any insight? The frequency function does work while running. The 18x signal made some sense, showing 325Hz, which would seem about right for a slightly raised idle due to initial start (approx. 1000rpm). The other signal, labeled as 3x, doesn't make sense, showing around 160Hz. At the same engine rpm that would be more like a 9x signal?? Is this maybe indicative of some sort of error that could be used for diagnosis? Supposedly, the engine will continue to run with one of the signals out of whack (don't remember which one) but not the other, or both. I think the check engine light is supposed to come on and you are instructed not to shut if off and get to a service facility because while it will run, it won't restart.Ronnie, don't despair. The instructions are good, unfortunately mine won't stay broken. A VOM with the frequency function isn't terribly expensive. Mine is from Radio Shack but I'll bet there are others for a good price in other places. Link to comment Share on other sites More sharing options...
padgett Posted June 27, 2011 Share Posted June 27, 2011 If you really want to troubleshool things like the MAF and the CPS, you really need an O'scope. Link to comment Share on other sites More sharing options...
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