Rough Idle 87 GN

[speedskills]

Hello everyone. Im a new 87 GN owner last week. Problem is it has a rough idle and sometimes dies at idle. At 15-20psi boost she runs like a scalded dog. Fuel pressure is at 42psi per previous owner. Not sure of the turbo size but it is a diffrent model than stock. Upgrades that i know of are: Custom intercooler, Kenny Bell cold air kit, fuel pump, 3" downpipe, headers, 2 1/2" duals, fuel pressure regulator and guage, adjustable waste gate, stock block and heads, throttle body and plenum are not stock (dont know the size). Not sure bout the injectors. Pretty sure i need a scanmaster. I think the car just needs some tuning but dont know where to start. Any help is greatly appreciated. Nice car but not perfect.

 

[Junior Samples]

welcome

got to www.fullthrottlespeed.com and buy a scanmaster before tinkering.

once installed you can get the IAC readings as well as your TPS so you can get your baseline to set your tune.

untill then dont dink with it..

and that "idle screw" you see on your throttlebody.. is your IAC adjustment.. if you dink with that, it throws your TPS off and without being able to read the voltage, you cant get it right and it will just run like chitty chitty bang bang

 

[speedskills]

Thanks Mc thats what i'll do then. I'll let u know when i get her running right. I'll put some pics up also. thanks again.

 

[Junior Samples]

untill then search around for tuning tips etc.
Installing the SM is easy and comes with details on what functions it provides, we have it on cars because its quick diagnostic.

While your waiting on the shipment, take pics of stuff you have questions on, injectors maybe, pull the ECM, remove the small cover and take notes on any writings on the chip.

Was at car get together last night and a small gang of tuner kids where comenting on thier dream car.. aka "The TurboBuick"

 

[speedskills]

Thats what i'll do then. Thanks for the info. The kids sound like they got it right if they like the go-fast.

 

[speedskills]

injectors

Heres pics of my injectors and turbo. Not sure if the injectors are stock or what kind of turbo i have.(cant find an ID plate on the turbo). Thanks for any help.

 

[billhead]

check for vacuum leaks especially the plastic block on top of the dog house.

 

[speedskills]

Cant find any vacuum leaks. thanks though. Guess i'll have to wait for my scanmaster. Who does this many mods without tuning?

 

[J_risch]

Hope you don't mind if I jump in here. I kinda got the same problem. Idles like crap. Anytime I leave from a complete stop I get a bog then go effect. If I get into it runs great though. Last year I got into it and the high rpm of first gear a loud pop. Blew out the gasket between downpipe and turbo. Cam sensor took a crap. Replaced it and now having this issue. By the way I have1000 miles on rebuilt motor. eagle crank rods je pistons, champion iron ported head and intake 212-212 roller cam. Still stock turbo. Looking to get this thing running right before bigger turbo. First 700 miles on motor were fine till the cam sensor thing.

 

[speedskills]

I dont mind

I'm a new GN owner and obviously got a lot of learning to do. I'm not car "stupid" but turbo cars are a little more complicated. The previous owner did some nice mods but must of had someone else tuning it or maybe not tuning at all. Stock block and heads but nice bolt ons. Just not sure of turbo type or injectors. I know its hot-wired and larger fuel pump. Dont know what kind though. I'll let yall know when i get my scanmaster. Then we'll go from there. Any info is appreciated though.