Chasing my tail...new to turbo buick scene problems

[VenomGT]

I am not new to this forum because I used the resources in it to rebuild and enhance the 2004r that I swapped into my Chevelle but long story short, I purchased a 1987 G-Nat and it was all good and great until one day it started to stumble and died, it would crank but not start....I looked around under the hood nothing seemed to be out of place didn't touch anything and closed the hood....tried to start again still no start just cranking....don't ask me why but I opened up the passenger side kick panel and looked at the ECU/ECM (not sure the difference lol) anyway the lid was missing to cover the chip and I removed it looked at it and put it back...tried to start it again and it worked.....now...the car still does this randomly shuts down out of nowhere (engine light flickers) and so far a couple of light taps on the passenger side kick panel fixes it right up, to me it feels like a loose ground but the ECU/ECM was (and still is) wrapped in a heavy plastic bag and none of the wires from the connector look like a ground that would be near the connector.
I have also noticed that right after this happens the car seems to run extremely well, it has happened cold and hot and it is just getting annoying.
I don't have a scan master (one is on the way) I did use one of those $30 reader plugs and I got six time code 12 so based from the tech pages means all is good (which could be false if the ECU/ECM is loosing ground)
Any help is appreciated.

 

[ITSAV6]

Check the chip pins for corrosion, bent pins, chip socket for corrosion. Remove the harness from the ecm and check for corrosion also. Check the ground wire that are on the rear of pass side head.

 

[VenomGT]

I couldn't find any grounds on the rear of the passenger side head but I did find one directly from the battery to the turbo shield bracket, I checked all the connections at the ECU and they are all good the locks on the smaller plug is missing but it took some finessing to remove it so I think is safe to say it was tight...lol
I'm still trying to get used to working on a car that has been worked on before, I am slowly figuring out that the previous owners have done most of the easy upgrades to the electrical, I got lucky with my 'velle had 7k miles and has so far had no surprises...lol

 

[NY Twin Turbo]

Why was the computer wrapped in a plastic bag? That answer may lead us to something. It's common to have water leak from the heater core/cowl/passenger side firewall area and soak the carpet. Maybe it's a water issue and the original owner knew this? Hence, the plastic bag.

 

[VenomGT]

I know the window leaks above the window seals, the foam seal that used to be there is dry rotted and has moved on to a better place so water drips in from above the rubber. It damaged the upper door panel but the ECU looks to have never been exposed to water. Right now the ECU is on the floorboard because I am checking for cracked, shorted or broken wires.

 

[ITSAV6]

I couldn't find any grounds on the rear of the passenger side head but I did find one directly from the battery to the turbo shield bracket, I checked all the connections at the ECU and they are all good the locks on the smaller plug is missing but it took some finessing to remove it so I think is safe to say it was tight...lol
I'm still trying to get used to working on a car that has been worked on before, I am slowly figuring out that the previous owners have done most of the easy upgrades to the electrical, I got lucky with my 'velle had 7k miles and has so far had no surprises...lol

There should be several wires grounded there unless they have been relocated...

 

[NY Twin Turbo]

With the car running, can you smack around the ECU and get the problem to expose its self? That may help. If you have a local Buick buddy I'm sure he will let you swap out yours for his to see if the problem goes away. Then you will know if you need a replacement.

 

[VenomGT]

Will do, I'll report back.

 

[VenomGT]

I just went out for a drive and it happened again after 22 minutes of driving sitting at a light, it felt exactly like a really bad misfire and the check engine light was flickering fast, I let it do it for roughly 10 seconds while in neutral (it dies on drive) and as soon as I tap the ECM it goes away. It then happened again at 37 minutes of driving I was cruising and there was a complete loss of engine power, light was flickering like before and I wacked the ECM with a bottle and went away.
I tried handling, tapping and shaking the ECM sitting at idle and could not replicate the issue.
Would it throw a code if the ECM is bad?

 

[VenomGT]

Tomorrow I am going to try out changing the chip, I've read at least 30 thread describing similar symptoms and they all say the chip may be bad but only two reported back with results...

 

[BMR]

Tomorrow I am going to try out changing the chip, I've read at least 30 thread describing similar symptoms and they all say the chip may be bad but only two reported back with results...

That's one thing I hate about this board. Very rarely is the resolution to a problem posted.

 

[turbotroy]

Had same issue. Swap the ecm out and be done with it, and find out what's up with your grounds. These cars do all kinds of weird stuff if not grounded properly.

 

[TurboTnZ06]

I keep a spare ECM in my car at all times now...

 

[NY Twin Turbo]

Could be a combination of heat and water. Something gets hot and then steam/moisture starts and begins to mess all kinds of sh/t up. Do the swap with a buddy to double check. ECU are readily available all over this board. A million guys don't need them anymore. I gave mine away a long time ago. XFI, of course.

 

[RmvBfrFlght]

With the fast flickering CEL the PROM is loose in the socket. You R&R'd it once to correct the issue, so it matches up.

Remove the PROM and get a small pick to re-tension the PROM socket. Get behind each contact with the pick and move it toward the center of the socket a little. Do all 24 contacts.

RemoveBeforeFlight

 

[VenomGT]

So I replaced the chip with the "street tune" chip and so far the problem has not occurred again, I also checked for the grounds and I found the bunch of grounds behind the engine toward the passenger side, right under the coil pack and they all looked good and just to be sure I loosened and cleaned all the wires. I also noticed that the air box leaks a TON of cold air, it goes out all around the heat shield so the box may be cracked behind it, it is really hard to tell without removing it.
I ordered a spare ECU from advance just in case. Now I am looking to upgrade the MAF to the 85mm/Z06 with a translator from full throttle speed but first I need to make sure my previous issue is resolved as to not aggravate the problem. Thanks for the replies and if anything changes I'll report back again

 

[VenomGT]

Just another update, the car has driven great, for some reason I have to run 93 with octane booster if not the knock gauge lights up every time I step on it or whenever the engine is under a higher load (up hill).
The new issue I have seems to be bad turbo seals, it looks to be leaking from the center section, and it every now and then it will smoke out of the exhaust progressively getting thicker (blue-ish gray smoke), it take a couple of minutes to start smoking so I am assuming the down pipe is coated with oil but also sometimes doesn't smoke at all...at this point I am just going to take it apart and get a good look at what may be going on...chasing what I thought was an electrical issue drained it out of me and don't really feel like dealing with it but at the same time I like how quick the car is so we will see, I may just send the turbo to Limited Engineering to have it rebuilt...its a TE45A btw

 

[NY Twin Turbo]

Check your fuel pressure. How Much Boost? Is the 02 sensor in the down pipe or header?

Don't let that knock gauge go off! If it knocks, get off it. Or don't drive it till you find out whats wrong.

 

[VenomGT]

Fuel pressure hops around 65 (I believe the pump has a hardwire installed also since the lights get brighter when I get into boost ad has a pressure switch on the back of the alternator, I am assuming it has that direct power wiring kit as well.
It has 55# injectors. right now boost is 15 psi knock sensor turns on the first light at 15 psi sometimes it stays on, sometimes it goes away and other times it goes all the way across at the same time, sometimes there is a noticeable power loss and other times none at all. Also today I started the car and there was a slight bit blue-ish smoke but nothing else after that. So I am debating if it was a drain back issue or a failing turbo seal.

 

[NY Twin Turbo]

Your alternator probably has a Casper's Volt Booster jacked into it. This is a little black box about 2 inches square piggy backed to the harness at the TPS and alternator. This increases your electrical power about an additional 2 volts whenever you pass about 75% throttle. This will make your headlights brighter along with adding more juice to fuel pump and ignition.

I would recommend not tolerating any amount of knock. In any amount, knock destroys motors. However, first you need to determine if it's a false reading. Make sure there is nothing banging around under your motor or headers. Look for witness marks. Check the motor mounts. Are they stock? Headers hitting anything? I hope your using good gas. After that, richen the crap out of it. Add 3-4 psi of fuel or more if necessary . Get it to go away. If you over do it with fuel, and it goes away, then you know the answer is somewhere in the middle. Then you can work safely subtracting fuel. I'd start there. Timing is next. find out what's in the chip and who made it.

Oil smoke? Just a little? Ignore it for now. Get the knock to go away first. When the oil problem becomes more frequent it will be easier to diagnose. No sense in pulling things apart for a puff at startup. It will smoke like crazy before something bad happens. Then you deal with it.