my 87 GN died while cruising light throttle 25mph, NO restart?

[TURBO E38]

Friday afternoon, I had to have my car towed home on a rollback.

I just had been running it for about an hour in Ocean City, Maryland Endless summer cruise weekend, I stopped in for some of those famous Phillips Seafood lump meat crab cakes to take home to Delaware. After about a 20 minute shut down, I resarted the GN and the rpm's flared way up to 3500 rpm I guess, I shut it off and then restarted , Everything OK, got on the road heading North to Home 10-20 and into about 3 minutes the car Conks out, tried to restart, NO SOAP, I coast to a side street and tried to restart a couple more times , NO LUCK, I call tow truck, Car is at SHOP now, Will not get any INTEL until next week, I had FULL fuel pressure from my hood mounted gauge.

ANY IDEAS, I got it narrowed down, ECM, COIL DRIVER MODULE, CRANK SENSOR, JUST A FUSE Somewhere, TRANSLATOR, Extender chip, Loose connection somwhere.

THE car has been outside and we had a lot of rain here begining of this week, plus I washed it pretty good before taking it down to OCEAN CITY.

I got a pretty good mechanic, and I have had quite a bit of experience with tinkering with these cars for the last 10 years or so.

I just don't know where I can lay my hands on the 87 G body electrical wiring diagram, I know that GNType has the ECM schematic and trouble guide that I have printed out.

ANY IDEAS, REGARDS, TURBO E38

 

[twin 93 svt]

ecm inline fuse, maybe wires off starter, hard to tell from just that info, is fuel pump priming?

 

[TURBO E38]

Fuel pressure was increasing with key up.

Fuel rail pressure was OK and holding with very slow leak down which is normal, With RE-Start attempt, the fuel pressure did jump up, SO the pump is running for a short few seconds.

I run my fuel pressure lower that normal with a diode feeding the OEM pump wiring, When I hit about 7 pounds of boost, a hobbs boost switch kicks in the hot wire relay and pump voltage is about 13 at the the pump, I would guess it is about 10.5 to 11 volts when not in boost. THIS is so I am not returning alot of fuel to the tank with the 255lph pump at full voltage and heating the fuel.
Something I pick-up from an old kenne bell catalog.
THE two speed fuel pump arrangement is like what the 3800 Series II supercharged scheme does. They increase voltage to the pump under boost by shunting a resistor. I just switch between the factory harness and the hotwire harness plus I slow the pump down BY the 600-700 milivolt drop across a silicon rectifier.,this arangement also serves as a backup voltage supply to the pump, If my fuel pump hot wire relay fails.

Will start next week checking fuses, I might be that lucky? also for any lose connections, will check to see if I got spark and check one injector with a test lamp to see if the fuel injectors are pulsing, I guessing a Crank sensor, or Cam Sensor. IT will be interesting. ECM is possibility also,

I have got a spare ECM, but I got to rob it from my other car, I have also got a turbo tweak 60lb injector chip in case it is the translator or the extender chip.

It really sucks when your car quits when your having fun, at that point the fun is OVER, but the fun starts again when you track down the problem!!

Thanks for the reply, Regards TURBO E38

 

[84BuickGNYorkPA]

Read Vortex Buicks go to the no start section.

Chuck

 

[TURBO E38]

Thank you, I have taken a look there and GNType

Your 84 GN in the low elevens, PRETTY IMPRESSIVE !, are you running hot air set up?

I would be interested in where you are injecting your alky?

IS your intake manifold stock hot air or modified like a V1?

I want to inject alky on my stock hot air intake on my hot air turbo riviera, I got a real short cam 188/188 reed 236H( REED RECOMMENED THIS CAM FOR THE PIG HEAVY RIVIERA) with harland sharp roller rockers on champion iron heads. I have 109 Normally aspirtated block with TRW turbo dish .020 over pistons with just one steel shim GM head gasket, ( I wish I had used .040 or .060 cometic's) the lower deck height of the newer block along with shaved champion heads with 2 cc less chamber area put my static compression ratio over 9 to 1, even with 104 octane unleaded race gas I get knock in 2nd gear at part throttle with 850 O2 millivolts, I can hear the ping and see the knock in caspers gauge and will get KR counts on my scanmaster, I have had chips from just about everybody and I have come to the conclusion that I am not going to be able to run much more than 10-12 lbs of boost even with the good gas. I also am jamming more air into the cylinder with the ported heads and the ta33c. I probably making as much power at lower boost levels. I could run 20 psi in 1st and 2nd with the stock turbo and 15 lbs in 3rd and 4th before on the old motor with 100 octane.

THE advantage is that my off boost VOLUMETRIC EFFECIENCY is higher for better mpg and snappier performance. IT PROBALBY doesn't make any difference!

THE more I do to this car, the more I screw up!!!!, BUT MY GN RUNS GOOD Or RAN GOOD until last friday afternoon.

SORRY to bend your ear, REGARDS>> TURBO E38

 

[84BuickGNYorkPA]

Jack & Brian Cotton converted my car 3.5 yrs ago, of course I couldn't leave it alone and the mod's began....

Chuck

 

[turbofrank]

timing chain

 

[818GN]

THE car has been outside and we had a lot of rain here begining of this week, plus I washed it pretty good before taking it down to OCEAN CITY.

How are your door, window, and t-top seals?

Maybe water got in, went down the A-pillar and came in contact with the ECM??

Had a similar issue after having my GN in a week long rain.

 

[TURBO E38]

T-TOP seals ?

NOT sure on the T-top seals , but I do have those ill-fitting head liners installed, they have warped and curved pretty good, I do know the REAR WINDOW LEAKS BECAUSE OF RUST CANCER AROUND THE WINDOW.

Wouldn't That be something if It Starts up and runs ok after being dried out!!

AS TO THE timing chain , I hope not, this is a low mileage car, under 45k, and a timing chain is a BIG DEAL repair removing the front cover and the intercooler and assoc parts, I don't even want to think about it. THE ONLY GOOD THING ABOUT PUTTING IN A NEW TIMING CHAIN IS THAT I COULD ALSO REPLACE THE FRONT ROPE MAIN SEAL WITH A NEOPRENE UNIT, AND DO SOME BLUEPRINT WORK ON THE FRONT COVER OR BUY A BLUEPRINTED FRONT COVER.

THIS CAR ON MINE IS JUST A STREET SCREAMER, NEVER BEEN BRAKE BOOSTED, NEVER BEEN TO THE TRACK, I WANT THE TRANNY TO LAST A WHILE!!

THANKS FOR YOUR INPUT, REGARDS, TURBO E38

 

[TURBO E38]

CAR now starts , IGNITION MODULE suspect

This afternoon, about 2pm is the first time the shop has looked at my GN, My mechanic gets in my car and the Darn thing starts right up, With years of experience under his belt working at a Chevy/olds dealership in the past, He suggested it probably is the Ignition coil driver module under the coil, and that it failed after it got hot, the first time I know about took about an hour and half, then after a 20 minute heat soak while the engine was off picking up my dinner last friday, it failed in about 2-3 minutes after starting again for the 25 minute ride home.

He suggested that the time interval from cold start to failure will get less and less from his experience.

Does this ring a bell?

How many have had a ignition module failure and what were the symptoms?

REGARDS, TURBO E38