1989 Reatta - finished 8 month restoration - now with engine trouble *SOLVED*

[Fox W.]

Off topic, but is this all the major hardware one needs for our LN3 to supercharge it? 3800 supercharger Complete | eBay

[Machiner 55]

Uh-oh, seems that Mr. Fox here is thinking of taking a trip to the wild side.

John F.

[Fox W.]

*Chuckles* I really don't want to go down this road, but it has been in the back of my mind for years. I am soo busy these days that I just know it would take me forever. But I admit a part of me would love to try the result. I guess now as the car is in such nice shape I feel more willing to make such edits. Though I don't want to put such stress on old parts or the transmission, she is 160k old.

[DAVES89]

I think jon [63viking] should weigh in on this. If I remember right you will need a power steering pump with a remote tank, as well as a few other items. I have always thought about doing it as well, but don't want to buy the tranny I would be sure to blow out...

[Machiner 55]

Fox W.,

In addition to Jon that Dave mentioned, there was another poster here that did the 3800 Super-Charger upgrade. His name is Phil C. He went by the moniker F14CRAZY. He spent a quite a bit of time posting his progress. You might want to perform a search here if you are interested in knowing what all's involved in the process.

John F.

Edited March 1, 2013 by Machiner 55
Spelling (see edit history)

[Fox W.]

Oh yes I remember following all of F14CRAZY's impressive work. He seems to have more time than I do, all that custom work to do a 6-speed. Maybe I could just pay him or someone to do mine.

Fox W.,

In addition to Jon that Dave mentioned, there was another poster here that did the 3800 Super-Charger upgrade. His name is Phil C. He went by the monicker F14CRAZY. He spent a quite a bit of time posting his progress. You might want to perform a search here if you are interested in knowing what all's involved in the process.

John F.

[padgett]

And a computer with the right maps (EGR is totally different & if you try to use a n/a PROM you will lean out) and with maps for the 4T65E trans. For someone going in cold, just buy a whole L67 GP and you will get nice wheels also.

[Fox W.]

I shouldn't continue this tangent without first refreshing myself very well on all that has been posted about it over the years. If I get serious I will do obsessive research and then ask questions, or as I encounter issues.. I've been without my Reatta long enough that I don't want to start something else that will give it down time.

I just know my goal based on personality would be to preserve as much that is original as possible, putting a lower priority on the performance gain itself. Thanks.

And a computer with the right maps (EGR is totally different & if you try to use a n/a PROM you will lean out) and with maps for the 4T65E trans. For someone going in cold, just buy a whole L67 GP and you will get nice wheels also.

[Guest BJM]

I read everything. Unless I missed it, no testing is being done under load. You mention the condition occurs under load, so you should try to duplicate testing this way.

Since you found one plug to be wet, this tells me there is a misfire under load. Spark test by placing your tester where you can see it, then place in gear, foot on brake and run it up. Don't go crazy or do it too long and let the car idle between but I want to see if the spark gets intermittent or craps out all together.

Any follow up on Barney's suggestion to check OBD?

Finally, as a deduction one would think that the issue would be related to what was changed from before the 8 months. That is, gas tank and related. I would certainly change the fuel filter and consider installing a new pump if you have not done so already (can not remember).

Check the ground for the fuel pump.

[Fox W.]

Thanks BJM, I will certainly be doing as you say next. Update: New Bosch III fuel injectors installed, zero change/improvement.

[Fox W.]

Actually I noticed it isn't as stable with idle now, in fact it seems like it is hunting a lot and is prone to stalling now without throttle. I reset the ECM and that somewhat improved it, I was thinking maybe it needed to learn something a bit different due to a change in injectors? I don't know, I am getting beyond my experience here.

I just checked the fuel pressure under load and found that at idle it is about 38psi, and under load it is about 42psi, very consistently so. (This was tested with brakes on, in reverse, 35% throttle for 4 - 5 second tests.) I also tested the coils under load it they looked consistent and normal.

Also I found that with the MAF unplugged it is unable to idle. I can restart it over and over and hold it running with throttle, but it won't idle.

Edited March 3, 2013 by Fox W. (see edit history)

[2seater]

It sounds like an IAC issue with the stalling or perhaps something disconnected/knocked off when the injectors were changed? It's operation may improve slightly as it relearns but as long as the injectors are about the correct flow rating, it shouldn't stall. It should idle without the MAF but everything else may need to be up to par as well. I believe Padgett suggested a snapshot of the sensor readings with it at warm idle.

[Fox W.]

Yeah I just restarted it and it is idling ok now, I think it was my error for not first resetting the ECU after these different injectors. My bad. Overall it revs better than when I started and idles with less pulse, even if it hunts a bit more. But the issue isn't better under load. I just removed 3 plugs, #1, #2, and #4. 1 and 4 both looked the same, kinda black but dry. Wiping them took off some ash but they were still black, except where they arc is clean. #2 which was the wet one when I did the plugs was only a tad damp with black oily stuff, very slight, and when I wiped it off it looked cleaner than the other two had then. I also notice when unplugging each injector, the idle and smoothness suffers, except for #2 injector, which has nearly no change. I checked the voltages on several injector connectors including #2 and they all read about 11.64v. Again everything is wired right and #2 tested normal for spark. Next I will do the snapshot and OBD stuff.

Note that the black plugs is maybe from all the injector port cleaning I did, lots of ash and grime from the walls I wire brushed.. It really needs a good run on the high way I imagine.

Edited March 3, 2013 by Fox W. (see edit history)

[padgett]

a) Sure sounds like an ignition problem, probably high voltage. Think you said it was a Delco ignition - what kind of plugs and where gapped please ?

Still have not seen a full ECM snapshot at idle

[2seater]

Hmm, I haven't tried this, but I would think you can switch plug wires are the common coil to see if the failure follows the switch. It shouldn't make any difference unless the reversing polarity at the spark plug makes a difference. I have a vague recollection that it is harder to fire the plug in one direction vs the other. The other option is to replace the single plug wire to #2 with anything good that can be laid in place for a try. I would sure put a compression gauge on that cylinder if the ignition doesn't help. Is the PCV good? It connects to the intake right at #2 port.

[jonlabree]

Try pulling #2 plug wire from the coil and hold it near the coil to see what kind of spark you are getting.

With the Delco coils you should see a very fat spark about 1" long. If not you have a bad coil or wire on #2 cylinder.

[Fox W.]

I know it does, yet everything is new and wired right, so I am stuck still with what is wrong. Remember I've tested every coil. The plugs are Rapidfire #14s, based on your other tread suggestions. I did not re-gap them, I thought I read they were gapped correctly already at .060.

I haven't had a chance to do that yet, sorry.

a) Sure sounds like an ignition problem, probably high voltage. Think you said it was a Delco ignition - what kind of plugs and where gapped please ?

Still have not seen a full ECM snapshot at idle

[Fox W.]

I'll try to play around with it in a bit in that manner, and the wires are completely new 8.5mm MSD wires, plus I have the previous set which were in good shape still that I also have been able to test with. The fact that none of the ignition alterations I've made (New plugs, new wires, new Jacobs coils, and ICM) caused any difference at all makes me feel I've still missed the mark somewhere.

Hmm, I haven't tried this, but I would think you can switch plug wires are the common coil to see if the failure follows the switch. It shouldn't make any difference unless the reversing polarity at the spark plug makes a difference. I have a vague recollection that it is harder to fire the plug in one direction vs the other. The other option is to replace the single plug wire to #2 with anything good that can be laid in place for a try. I would sure put a compression gauge on that cylinder if the ignition doesn't help. Is the PCV good? It connects to the intake right at #2 port.

[Fox W.]

Alright I'll try.

Try pulling #2 plug wire from the coil and hold it near the coil to see what kind of spark you are getting.

With the Delco coils you should see a very fat spark about 1" long. If not you have a bad coil or wire on #2 cylinder.

[padgett]

I only gap Delco ignitions at .060 (#14s) Magnavox or Jacobs (any square coil set) I gap at .045.

That said whatever was replaced last before it began is likely. Even plug wires have bathtub curves.

[Fox W.]

Jacobs makes both types, they make upgrades for Delco type, and upgrades for the magnavox type. As I mentioned before I converted to delco coils 7 years ago, so the replacements I got from jacobs are the delco type, 45k volt. "Jacobs 321411 - AC Delco Style."

I only gap Delco ignitions at .060 (#14s) Magnavox or Jacobs (any square coil set) I gap at .045.

That said whatever was replaced last before it began is likely. Even plug wires have bathtub curves.

[Fox W.]

Well I believe it is narrowed down to cylinder #2.

By either disconnecting injector #2 or doing so via the software it causes it smooth out and is the only way to get the ECU in to closed loop. I know everyone and myself keeps thinking this must be ignition but I am out of tests for that, the coil fires, swapping 2 and 5 makes no difference, the plug fires great, I've visually tested it all.

We even put an oscilloscope on the injector electrical plugs to watch the wave signal and found they all look the same and normal. The injectors are all new and matched. If I drive the car around with #2 injector and plug disconnected, it feels like you'd expect for one cylinder down but otherwise you don't even notice it much until you go under heavier load (where you get some shudder and it feels weak.) It idles far smoother and revs more freely in neutral.

If I connect #2 injector/plug, in addition to those previous negative symptoms I get a much more rough and unstable idle and overall it feels worse, plus never goes in to closed loop. If I disconnect any other injector than #2 it gets much worse, not better. #2 plug when removed tonight was again lightly slick with black oily fuel.

If it were not ignition and it were not fuel, could we be looking at valves now? Assuming the whole issue is a single cylinder that does rule out a lot.

[padgett]

Do you also swap injectors ? If so then run a compression test on several cylinders including #2. Does sound mechanical so my not matter that you are unable to run/post a snapshot.

[Guest BJM]

Well, I am kind of out of suggestions. But what about a worn cam lobe? Does anyone know if there is a GM Bulletin related to uneven cam lobe wear or something like that? Trying to think outside the box. Stuck valve? Something that would cause the combustion cycle to not be complete. If the injector is new and matched, all other parts are fine, you've done a boatload of testing. Maybe time to pull the head and see what is going on.

[ol' yeller]

This,

I would sure put a compression gauge on that cylinder if the ignition doesn't help.

[Fox W.]

Hi Padgett, I was hoping I could get this data for everyone from the CRT, but is that not so? Do I need a scanner? I was trying last night but I hadn't seen how to read that snap shot data yet after I took it. I did play around a lot though, purged vap. canister, manually turned the 3 EGR solenoids on for a bit then off. Turned injectors off manually, finding again that having #2 off smooths and evens it out, where as turning off any other injector makes it noticeably worse.

My friend will hopefully be bringing over his fancy compression tester today. I figured I may as well use his nice one rather than go support China some more.

Do you also swap injectors ? If so then run a compression test on several cylinders including #2. Does sound mechanical so my not matter that you are unable to run/post a snapshot.

[Ronnie]

Fox, did you receive the PM I sent you a couple of days ago? I never got a reply so I'm posting it here in case you missed it. Maybe it will help you.

-------------------------------

Hi,

As info... The numbers on the bottom coil in your photo are incorrect. Instead of 1/4 it should be numbered 4/1. I can't see the routing of the wires for that coil but I don't think the numbers will matter as far as the problem you are having because both plugs from that coil get spark at the same time. I would still connect them as they should be if they aren't already.

In one of your posts you said: "My clues: Plug #2 was wet and fouled looking, other 5 looked normal; have not rechecked since new plugs."

If I were you I would concentrate my attention on that #2 cylinder. Something caused that plug to be wet and fouled looking. More than likely because the spark plug wasn't firing. Since the #5 cylinder wasn't wet, I doubt the primary ignition system has a problem. I would test the #2 spark plug wire and spark plug closely to make certain they are working correctly... even if they are new.

Other causes of the #2 spark plug being wet could be coolant entering that cylinder via a bad head or intake gasket, or it is wet due to oil getting on it (possibly a bad valve guide or seal). I don't think it is wet because of excessive gasoline being injected into the cylinder. The Delco is a hot ignition system. Unless you have an injector that is stuck open the Delco system should burn off any excess fuel mixture in the cylinder quickly and the engine should start running smoothly.

If I were troubleshooting your car I would start by doing a compression test on #2 cylinder and replacing the spark plug wire and spark plug with ones that you are certain are good in order to eliminate them as being a possibility. I have made the mistake of assuming parts are good because they are new and it has come back to bite me several times.

Good luck with tracking down your problem.

-------------------------------

[Fox W.]

Thank you Ronnie, after seeing this I just read the PM a few min. ago and replied. I rarely get PMs and the notification system didn't give me anything overt, so I was unaware. Sorry about that delay. We certainly all can agree that it is time to do a compression check. As I mentioned in the PM I had since after your message visually made sure the plug for #2 is firing in a healthy manner.

I really appreciate all the support, it has been both fun to track this down as well as a bit sad at times that the shiny 'new' Reatta is sick, after not having it for so long I sure would like at least one nice drive.

Fox, did you receive the PM I sent you a couple of days ago? I never got a reply so I'm posting it here in case you missed it. Maybe it will help you.

-------------------------------

Hi,

As info... The numbers on the bottom coil in your photo are incorrect. Instead of 1/4 it should be numbered 4/1. I can't see the routing of the wires for that coil but I don't think the numbers will matter as far as the problem you are having because both plugs from that coil get spark at the same time. I would still connect them as they should be if they aren't already.

In one of your posts you said: "My clues: Plug #2 was wet and fouled looking, other 5 looked normal; have not rechecked since new plugs."

If I were you I would concentrate my attention on that #2 cylinder. Something caused that plug to be wet and fouled looking. More than likely because the spark plug wasn't firing. Since the #5 cylinder wasn't wet, I doubt the primary ignition system has a problem. I would test the #2 spark plug wire and spark plug closely to make certain they are working correctly... even if they are new.

Other causes of the #2 spark plug being wet could be coolant entering that cylinder via a bad head or intake gasket, or it is wet due to oil getting on it (possibly a bad valve guide or seal). I don't think it is wet because of excessive gasoline being injected into the cylinder. The Delco is a hot ignition system. Unless you have an injector that is stuck open the Delco system should burn off any excess fuel mixture in the cylinder quickly and the engine should start running smoothly.

If I were troubleshooting your car I would start by doing a compression test on #2 cylinder and replacing the spark plug wire and spark plug with ones that you are certain are good in order to eliminate them as being a possibility. I have made the mistake of assuming parts are good because they are new and it has come back to bite me several times.

Good luck with tracking down your problem.

-------------------------------

[Ronnie]

Well I believe it is narrowed down to cylinder #2.

By either disconnecting injector #2 or doing so via the software it causes it smooth out and is the only way to get the ECU in to closed loop. I know everyone and myself keeps thinking this must be ignition but I am out of tests for that, the coil fires, swapping 2 and 5 makes no difference, the plug fires great, I've visually tested it all.

We even put an oscilloscope on the injector electrical plugs to watch the wave signal and found they all look the same and normal. The injectors are all new and matched. If I drive the car around with #2 injector and plug disconnected, it feels like you'd expect for one cylinder down but otherwise you don't even notice it much until you go under heavier load (where you get some shudder and it feels weak.) It idles far smoother and revs more freely in neutral.

If I connect #2 injector/plug, in addition to those previous negative symptoms I get a much more rough and unstable idle and overall it feels worse, plus never goes in to closed loop. If I disconnect any other injector than #2 it gets much worse, not better. #2 plug when removed tonight was again lightly slick with black oily fuel.

If it were not ignition and it were not fuel, could we be looking at valves now? Assuming the whole issue is a single cylinder that does rule out a lot.

I hadn't noticed you posting this before. What you are describing is almost as if the injector is staying open or partly open anytime the car is running. The injector has power (12 volts) going to it constantly. The injector is opened by the ECM supplying a ground to it when it is time for it to open. Is it possible a wire between the injector and the ECM is shorted to ground or a bad ECM is keeping the #2 injector grounded all the time and holding it open??? Maybe you could tell something by using a stethoscope to listen to that injector to see if it is clicking which would indicate that it was opening and closing as it should. Edited March 5, 2013 by Ronnie (see edit history)

[Fox W.]

This was all in earlier posts, and I've mentioned using a stethoscope as well as later using an oscilloscope to watch the waveform. Everything checked out perfectly. Plus the injectors are new Bosch IIIs.

Since the culprit seems to be a single cylinder and yet fuel and spark check out for it, as well as the other 5, I am left to look at deeper issues now. I hope to have a compression check done tomorrow.

Thanks.

I hadn't noticed you posting this before. What you are describing is almost as if the injector is staying open or partly open anytime the car is running. The injector has power (12 volts) going to it constantly. The injector is opened by the ECM supplying a ground to it when it is time for it to open. Is it possible a wire between the injector and the ECM is shorted to ground or a bad ECM is keeping the #2 injector grounded all the time and holding it open??? Maybe you could tell something by using a stethoscope to listen to that injector to see if it is clicking which would indicate that it was opening and closing as it should.

[Fox W.]

My friend could not find the gauge so I got a compression tester plus a leak down kit, it will arrive Monday, more to come then.

[padgett]

Compression tester is straightforward but leakdown requires understanding of exactly what you are trying to do and a precalibration. See How to do Cylinder Leak Down Testing- Car Craft Magazine

[Ronnie]

Compression tester is straightforward but leakdown requires understanding of exactly what you are trying to do and a precalibration. See How to do Cylinder Leak Down Testing- Car Craft Magazine

The leakdown test is a useful test. It can also be a dangerous test. Anyone considering doing the leakdown test should be aware that the air in the cylinder under pressure can cause the engine to turn unexpectedly if care is not taken to prevent it from happening. The magazine article says to test at TDC. I guess that is ideal if you are looking for a perfect seal and maximum HP. They also say to rock back and forth around TDC which could really be dangerous if the air pressure is too high. I think they should have posted a safety alert in their article about testing at TDC in the manner they describe. IMHO.

[padgett]

BTW you need to be at the end of the compression stroke for each cyl. Also use TDC for 1, rotate 60 degrees for 6 and another 60 for 5. Then repeat for 4-3-2.

[zoltanb]

I would think the push from the compressed air would be minimal as the exhaust valve opens after detonation (tdc) there by leaking out the compressed air. But I maybe wrong.

[padgett]

What we have here are four strokes: intake, compression, ignition, exhaust. Typically the exhaust valve opens somewhere around BDC following ignition and the intake opens around TDC following exhaust. Overlap is when both are open at the same time and can be useful for improving flow. The place to measure leakdoown is near TDC between compression and ignition when both valves are closed. This will happen at different places in 720 degrees of rotation depending on the cylinder. It is difficult to tell which TDC you are at unless you pull the cam sensor and watch for the magnet or a valve cover and watch the rockers.

BTW for a leakdown test, the engine is not turning. The idea is that for a specific flow of compressed air into a cylinder, how fast does it leak out. Since a real flowmeter is expensive particularly for very small flows, a leakdown tester fakes it with one or two (preferred) pressure guages.

Edited March 6, 2013 by padgett (see edit history)

[Ronnie]

I can't say that I know of anyone having been hurt doing a leakdown test. If it's done correctly it might not ever cause a problem.

I can tell you first hand about my experience with air pressure and a small block Chevy engine. I had broken an inner valve spring on my '56 Chevy, 327 engine with a 4 speed. A guy at the garage where I worked told me about an easy way to change the spring without pulling the head using air pressure. I hadn't ever heard of it before but I decided to try it. I brought home the special tools from the garage that were needed to hold the valve up with air pressure so I could remove the valve spring retainer and keepers. Everything went smoothly until I connected the air hose to the fitting screwed into the spark plug hole. The transmission was in gear and the car moved forward just enough to bump my Dad's legs and then it stopped. He was standing between the front of my car and the rear bumper of his pickup truck watching his young mechanic son show him how a valve spring could be changed without pulling the head. We had no idea that the car could move. If the car had been closer to his truck my Dad would have been hurt. I really thought that I had the piston at bottom dead center but I was wrong. I learned a lesson that day.

[padgett]

Closeline method has worked for me. No air involved.

[Fox W.]

Whoa guys, no worries at all, I'm familiar with either process, I'll be good. My method is to put a piece of something light like tissue paper lightly in to the spark plug hole and wait till it puffs out a bit as you turn the engine manually, this tells you when you are on the compression stroke. From there holding something like a screwer in and feeling where you get just to the point the stroke is moving back down as you turn the engine will get you real close to TDC. Here is hoping the leak is not rings. I figure at best I will be removing the heads to replace valves if there is a leak, and at worse considering my options for replacement. There is an AC Delco reman LN3 long block on Ebay right now for $1400 shipped, no core. But to make it worth my while I may just prefer to find a low mileage L67 supercharged or something.

Edited March 7, 2013 by Fox W. (see edit history)

[Fox W.]

And thanks to you all for this great support. Let me know if my method is foolish and if this engine has better ways to figure out what is what for that test.