Why is my car dying?!

[elementalwindx]

Ok for some reason my car dies whenever, while driving down the road, I hold the clutch in and letting the RPM die down from 3+k rpm to idle. Instead of going to idle and stopping, it just dies.

a) It starts fine, idles perfectly, I can hit the gas and it will go up, and come back down to idle fine most of the time, but sometimes when I hit the gas and let it go up and come down, it'll dip down to like 100-200rpm and then go back up to normal idle of 750rpm.

If I'm going down the road and I put it in neutral and let the clutch out it will do just like (a) above.

Wtf could this be?

Mods are listed at http://members.cardomain.com/uncwdragonfire

Stock Autozone clutch replaced a year ago too.
T25 turbo is shot and is about to be replaced in a week or so. I think the seals in it are gone, and theres enough l to r shaft play to say I'm done with it.

 

[Game Over]

The Gs-T and GSX both do it here, and they only do it when it's really cold out, but not a whole lot for me to be worried. I just be sure to keep it in gear when going around corners, and when letting it out of gear, rev it a little before the rpm's bounce to 1k.

 

[Nanan]

Thats the same thing my car has been doing for the last few months. Last sunday the car started idle surging really badly 500-2500 rpm range. Then on monday the car would just die when I let off the gas. After a bit of research I realized that the ISC is dead, this componet is what regulates the engine rpm at idle and keeps it from dying when you let off the gas.

My guess is your ISC is dead, they can be purchased from mitus or autozone/napa/advanced for $225. You could also try a junk yard but you have the uncertanty of how long that will last.

 

[97EclipseGSX]

sounds like a tuning prob to me, maybe to much idle fuel or however the dsmlink adjusts that
or I guess it could be a vacuum leak

log it with dsmlink and see what the ratios and other things are when it stumbles

 

[moliver]

sounds like vacuum leak

 

[elementalwindx]

Thats the same thing my car has been doing for the last few months. Last sunday the car started idle surging really badly 500-2500 rpm range. Then on monday the car would just die when I let off the gas. After a bit of research I realized that the ISC is dead, this componet is what regulates the engine rpm at idle and keeps it from dying when you let off the gas.

My guess is your ISC is dead, they can be purchased from mitus or autozone/napa/advanced for $225. You could also try a junk yard but you have the uncertanty of how long that will last.

This was my guess too. I'm recirculating now but when I wasn't this ISC got so bad that I had no choice but to recirc. I am now a firm believer that venting on a MAF w/o the translator kills ISC motors because this is my 2nd one. This one was used I bought it w/ the entire TB.

Oh and I did a pressure test w/ the hose to the turbo inlet and I didn't lose any pressure. That wouldn't tell me where there is a vac leak tho correct? If not, then how would I be able to find it?

Hopfully soon dsmlink logs will come. Like tonight.