Help me 85T Idling Rough

[White Hell]

Hey guys, my second edition is an 85T have owned it a year..Car has new engine,turbo you name it..Came to me with this idling problem and i've had new vaccume lines and routed the correct way, tune up, new wastegate (that wasn't cheap) and a new vaccume switch.. so she runs real smooth driving, but the more i drive her the idle gets more rough.. get to a red light and she idles like a cam in a race car..(also orange check engine light comes on at times at red lights, goes away if i stomp on the gas pedal) it was a stock rebuild.. could it be the chip.. and what chip does everyone run or suggest to run with a stock 85T 3.8 Turbo, only mods are ATR pipes, and a new gas tank with a new hot wired Reds fuel pump.. thats about the only thing not stock on rebuild.. i have not put a scanner or any other type of test.. just my buddies garage and he couldn't figure it out (he's a mechanic but doesn't know much on turbo cars) he did hook up a scanner and couldn't find it, saying it must be the cam.. Got me, but puzzling.. i would like to replace the chip if you guys recommend a good one.. I run 93 Octane, and i'm not sure what chip is in this car.. i run a Jay Carter chip in my 87GN.. Thanks for your help... Tony

 

[crazygn]

I run a jl 93 and it works great. Have you tryed to pull any codes from the ALDL , put a wire on the top two right holes on the aldl and turn the key on but not to start it. See if she will pull any codes. You could also to to check the iac and tps settings.

hope this helps

good luck

 

[White Hell]

Thanks

Hey CrazyGN I'll sure enough try checking the codes, haven't checked any of that.. i too run the 93 street chip from Jay Carter in my 87GN.. really a great chip.. wish i would have kept my last years Jay Carter chip now.. I just gave it away last week.. too kind hearted.. but i get a new chip every year from Jay.. so i will see about trying one of those.. i think this 85T has a Trasher chip.. cant remember.. Thanks again.. Tony

 

[maneen]

Be very careful in repairing your problem. Keep it simple. Basicall a rough idle is usually a vacuum leak and I had my share. .Check the vacuum hoses for splits and being loose. Check the "t" connectors. My last problem was that. I think a bad cam might be a bit noisey and you might see some powdered metal under valve covers. Make sure all air filter hoses and pipes are tight, Good luck and keep it simple.Remember if it aint broke dont fix it.

 

[White Hell]

Thanks

I agree on the if it isn't broke.. i have had all new vaccuum lines put on, a new wastegate, new vaccuum switch and the engine is fairly new, so new cam and all.. its not that bad of an idle, but wanted it to be as smooth as my 87GN.. so all new parts and hoses.. going to try changing the chip first.. thanks, i do love my 85T, almost sold it twice but man is she solid and sweet.. I dont race so its a great daily driver that doesn't get driven that much..lol.. thanks T.

 

[JasonB]

My 85 did the same thing until I replaced the MAF, as you I went through the vac lines and all that. My check engine light was for a O2 sensor lean code. Mine also seemed to fall flat if I was at full throttle. Just something to look at.