86 GN Stumble

[BCBlues]

I have an 86 GN. Under the hood it is stock. The suspension is slammed and set up for canyon racing.

I am the origional owner (bought it new)

This car is a daily driver with 80K miles.

Over the years I have replaced all of the sensors, transmission, brake pump and related power boost parts.

My current problem has me stumped. This car has always run great.

When you gas it and get any boost over 3-5 psi it coughs, stumbles, and blows out a black cloud of smoke.

It started doing this suddenly and is showing no trouble codes.

I have checked all electrical connections, sensors, vacume lines. All are in good shape.

In the past when the car has done this it was always due to broken vacume lines to the turbo waste gate.

Suspect the waste gate or turbo has died.

[Hypsi87]

First, get a scanmaster or something to monitor your PCM. 2.
Check your grounds. When I put my t+ on my car last week, I had ground strap problems and it was doing the same thing. Also you might have a bad MAP sensor. Just because you have replaced a componet, does not mean that it is good. Just a thought on your problem.


Let us know how it is coming alog!!

Andy

P.S. what is caynon racing???

[kratefan]

Mine did that when I had the wrong heat range plugs in it. I'd also check the fuel filter and maybe have the injectors cleaned.
Jeff

[BCBlues]

P.S. what is caynon racing???

LOL!!! Way back when I set my car up to handle like the bat-mobile.
Lowered it 2" and stiff, bilstens, huge sway bars, 16/8" anrol wheels. Had Heim jointed rear track bars made for it. This car is set up for over-steer, loves to make a turn into a box. So canyon racing is my term for dustin anybody on a windy road. Squareing up tight turns or long drifts, the power band of the engine in stock trim is perfect for this kind of driving. Not to much, not to little.

Everyone does drag racing. Imagine a black tuna boat sized car with no emblems (sleeper) dusting a Porche in the mountains, and when the sports car driver askes me "God, what's under the hood," I just tell them "A little old 6cyl."


Thanks for the tips. In 18 years of driving ( wow) the car has hardly ever missed a beat.

I forgot about the ecm grounds. The one in that god-awful location behind the cyl head? I suppose its time for new plugs and filters, injecter clean too.

Oh yea, maby this has something to do with it. About a month before the problem occored the oem led tach went nuts. At idle it reads 3k rpm and goes to red line as soon as you increase rpm.

I'll give them (tips) a try and see how it goes.

[Hypsi87]

The oem tachs go nuts all the time. I am suprised that yours made it this long. mine does the same thing along with about 80% of the turbo buick crowd., just have to get a aftermarket tach for it.

[BCBlues]

Glad to hear that the tach thing is not a ecm problem. I guess I'll have to go with "Autometer." Maby on http://www.gnttype.org someone will have done just the right tach for this car.

I just finished doing this conversion http://www.automotiveforums.com/vbul...d.php?t=206558 to my wifes Jeep, and some mods to my Hyundai Tiberon so I am a little straped for cash.

The G/Ns' gonna have to sit till next month then I'll tackle it's problems.

Anybody know of a source for interior plastic parts? The plastic piece on the top of the dash that covers the speakers/defroster vents is shrunk and cracked in about 5 places on my car. Every Regal I look at in the bone yards has the same part in the same condition.