lsturbo*

I have a 98 LS motor that I completely rebuilt shy of the cams and crank. I have been having idle problems since the start-up but the symptoms are not consistant. I have no CEL, have cleaned my IACV, replaced and set the TPS within range, checked vacuum lines, and still the roaming idle. Usually the car runs really high on initial start-up in the morning(like 2000 - 2200 RPM) then will run too low when warmed up(100 - 500 RPM) and today on the ride home it stalled everytime I came to a stop. When I restart the car, it barely idles, and if I rev it up it - it drops down and stalls everytime(at least today).

This is hard to diagnose since it never did idle correctly so it can be anything...and this motor was put into a 98 GSR shell and I did have some wiring issues. However, like I said, no CEL...

The motor was rebuilt to spec except I went to 83MM bore - any ideas on what my problem can be?

vietnamezerice

what kind of wiring issues did you have before?

xsi90teg

mine does that when my gas gauge is at half way,,, the *** i bought my car from put a 255 walboro pump in half asses and now i have to fill up at half way but everytime i would slow to a stop it would act really weird try topping the gas off and see what happens then

lsturbo*

wiring and other problems I had before were;

1.) Replaced the TPS b/c it did not test out to spec - did not fix the problem

2.) 1457came on so I replaced valve on top of purge canister - did not fix the code, but the valve was bad

3.) 1457 still on - Purge selonoid was not wired correctly, somehow the VTEC wires were running to it - this threw a code and I traced the wire and fixed it. (keep in mind I have an LS so the VTEC wires were extra on the car) - this fixed the 1457 CEL

4.) Threw another code, for low TPS circuit, so I dialed it in to be .5V closed, and 4.5 open - this fixed the CEL for low input

Now I have no CEL, and the idle sucks ***, anymore ideas? The fuel pump idea was interesting, by I am 100% stock in that area, could it be bad or dirty?