View Full Version : running Rough

09-03-2005, 08:12 PM
I have an 85 T-type. It is running rough. It is blowing black smoke at idle and reving the engine and while driving under boost. I am talking about a lot of black smoke. While sitting the black pile that is left on the ground appears wet and smells of fuel. The engine was just rebuilt before I bought it and they told me that it was running rich. It does have a slightly more aggresive cam than stock. There is a crack in the charcol canister. The person I bought it from took it to a shop called turbo technoligies and they said that the problem was in the wiring harness, that the computer was registering that the car was running lean and dumping more fuel to try to correct it when the car was not lean. I too have talked to the guys at turbo tech and they say the only thing I can do to fix the problem is to get a stand alone fuel management system. IS this correct or can it be something they are over looking? What tells the computer how much fuel the car needs? Thanks for any help I can get.


09-04-2005, 08:57 AM
Do not have experience on the pre86 but here is what I would suggest,
get some scantool readings to where you can show us what it is doing
verify what the fuel pressure is set at
check for vacuum leaks (spray starting fluid at all vacuum hose areas) (be careful spraying)
You could plug off the vacuum canister to fix that leak

You do not need a stand alone fuel system and I doubt you need a wiring harness.
What you need is a turbo buick mechanic.

09-04-2005, 12:09 PM
I think that 'shop' is incompotent.

You need to get a scan tool on the car. Something probably has it adjusted to full rich for some reason. Could be -

- bad or shorted O2 sensor
- wrong chip for your injectors
- bad temp sensor
- leaking vacuum hoses

or a myriad of other things. An aftermarket manangment system is NOT the solution here.

09-04-2005, 07:38 PM
The fuel pressure is about 40psi at idle. The computer is throwing a code 51 bad prom. I have a box full of chips that came with the car so I am going to try to see what they do. I will try to get some more info on what the difference in the chips are. The vaccum was wrong but I have corrected that and that showed no change. The engine is bored .030 over and the crank is .010 under. THe only info I have on the cam that he put in the car was that it is slightly beefier what ever he means by that. Could the cam be hurting me?

09-04-2005, 08:55 PM
ok i took out the chip he had in the computer, which when i bought the car i was told it runs the best with it, and changed it with a custom chip from jet. the chip that was taken out of the car had CARB on the sticker, the chip we put in had CUSTOM writen on it. with the CUSTOM chip the car runs just fine, no smoke at idle or WOT and the engine purs like a kitten. next problem to fix is the oil issue. there is oil all over the driver side of the engine, at this time we have not been under the car to see if it the dip stick is not secured right or if it is something else down there or if it is somehow spitting out of the top of the dipstick tube. thats where i stand for now wil post more info as i get it. if anyone has any suggesting please let me know. on a side note if i ever see the guy who rebuilt the car and sold it to me it will look something like this :chain: !!!!!!!

09-04-2005, 09:40 PM
FWIW, JET does not even make TR chips any longer. So those you have are VERY dated.

I would suggest investigating moving to an 86/87 ECM. Its used on several other cars, and more widely available. Plus, you could move to newer chips and use more scan tools that way. Instructions are elsewhere on this site. (Not in the Forums)

09-04-2005, 09:56 PM
i was actaully thinking about doin that. where would be the best place to hunt one down?

09-05-2005, 04:04 AM

Anything that has that ECM in it. 1986 Century, LeSabre, Electra, Delta 88, Cutlass Ciera, 98. Engine code 3 or B.