Possible Idle surge and Rich condition

[Prymal]

I just bought a 91 ESI turbo conversion. the only issues i am having with the are idle surge between 500 rpm and 1000 rpm. when i am in neutral and brake on a hill i almost kill the car as in all of the warning lights come on the RPM gauge drops just below 500 rpm before it revs back up to 1000.

Any suggestions on what to look at to try and fix this?

The other issue i am having is just a guess please tell me if my thoughts are correct.

I have a narrow band AFR guage that swings between no reading and just past stoich on the Rich side when I am cruising. When I get into WOT full boost it stays still just past Stoich on the Rich side. The car has a big 16g turbo running 14 to 15 psi and an AFPR set to 40 PSI what should i adjust to try and remedy this a little before mess something up while I save for tuning equipment?

 

[Fotowntalon]

Try cleaning your IAC, i think its the bottom sensor on your TB... if i am picturing it correctly in my head. Also, you say its worse when you are parked on a hill? facing which direction, with the hood on the downslope or the tail end? that almost makes it sound like you maye have a fuel pump going bad or something along those lines, almost like its having trouble having fuel reach the fuel rail.

 

[Prymal]

it happens most with the nose going down hill. I would be suprised if it was the fuel pump because it has less then 6 months of use. also if the fuel pump was having issues getting gas to the fuel rail i dont think i would be running rich. I could be wrong though.

 

[Fotowntalon]

I'm wondering if your 02 sensors are ok... it would be possible that there malfuntion could be casuing you to run rich, and in turn making for a bad idle.. could be wrong though. Did cleaning the IAC help at all?

 

[Prymal]

i am going to clean it today along with check all of my vaccum lines.

can i confirm that it is the bottom sensor on the Throttle body? and what should i use to clean it?

 

[Fotowntalon]

Carb cleaner i beleive is what most poeple reccomend. I don't know how different the 2g TB is form the 1g but i just googled images the IAC and this is about what the 2g's looks like

http://www.techknowman.com/Dodge Neon/T-BodySm.jpg

I'd go by that unless you have a haynes/chilton that says otherwise.