runnin rich and sluggish

[ryno]

i have recently purchased a 1997 gst, mods are k&n filter with turbo back exhaust.

the car seems to run rich( i think)....the smell of the exhaust is very overwhelming, i am getting very bad gas millage, and the car just doesnt seem to be boostin like it should past 3500-4000 rpm(my old rs seems faster, no joke)

another thing, if i sit in idle and punch the gas the rpm will go up like normal, but then drop down to like 700rpm real fast and then go back to idle rpm. and if im driving and i down shift or put clutch in to turn or stop...the rpm's do the same thing, fills like it s gonna die, but never does....

what do you think the problem is?
please help, im a real newbie when it comes to boosted cars

thanks ryan

 

[K_Hill]

Do a boost leak test..

http://www.vfaq.com/mods/ICtester.html

 

[ryno]

so you think its a boost leak....would that mess with the idle like i said and have bad gas milage? like i said im a newbie with boost...so please help and dont flame me

thanks ryan

 

[K_Hill]

This website will answer (mostly) all the questions you have..

http://members.shaw.ca/costall/1000Q/


But I would suggest you do a boost leak test..
Does it throw a CEL?
Have you tried to adjust your BISS screw?

 

[alex]

That is probley one of the first things I would do is a boost leak test. You can easily make your own or you can buy one for like $20 or less.

Just in case you didnt know, CEL stands for Check Engine Light and the BISS stands for Base Idle Speed Screw. Here is a link on how to adjust your BISS

http://www.vfaq.com/mods/BISS-2G.html

 

[oldman]

so you think its a boost leak....would that mess with the idle like i said and have bad gas milage?

Yes.

 

[ryno]

no cel, would it be the biss tho, cause it still idles fine when just sitting....if you guys are pretty sure its a leak, i probally need a new licp, and uicp, where would you buy these...cause i dont have a lot a mula right now

you guys dont think it is the o2 sensor do you?

thanks ryan

 

[andymoraitis]

Ryan,

If your O2 wasn't functioning properly, it would trip a CEL (make sure your CEL still works when you turn the ignition on or the bulb could be burned out or disconnected). If you have a friend with a logger, you can run a 3rd gear pull and look at the 02 voltage. An O2 that's going bad will think that the motor's lean and keep dumping fuel while showing lean ranges (around .82-.84v or so) on the logger.

Another thing to consider is that your ECU naturally runs a rich 9.5:1 air/fuel ratio from the factory. This isn't optimized for performance, but is calibrated this way to keep the motor safe from detonation. While boost leaks in the intake system can aggravate this condition, exhaust leaks before the O2 housing can also cause similar issues.

A boost leak test is your best friend right now and I would advise you to start with the basics and move forward from there.

Andy

 

[ryno]

Thanks guys,

I will try to do a boost leak test here in the next day or two, and will inform you guys about the results.Thanks.