Hey guys,

My B20's idle is still all over the shop and running a little rich. I can't see it being a vaccum leak because I've been over the intake system that many times now.

Some questions though:

Could the skunk2 IM cause this because it may causes different vaccum characteristics and is confusing the map sensor?

Because its an OBD2 motor with an fitv and an OBD1 LS ecu... are they stuffing eachother up? Because I know motors that don't have an fitv use the ecu to control the cold start idle.

The car drives around fine... blows a little smoke from running about rich and bogs a little at low rpm... its just the idle thats really getting to me!

My questions sound a little noobie... but some help would be appreciated!

Cheers!

did u try adjusting the idle with both idle screws

skunk2 IM haves a sensor look at it may be bad what is ur ecu code?

i have one too and after i got it tuned they told me that, the sensor on the IM was bad and yes i have a b20 on skunk2 IM OBD2 motor and an OBD1 LS ecu.

I've tried adjusting the idle with the screw... but its not that it sits too high or low... it rises slowly, then drops to like 400rpm and slowly rises again... My fuel pressure gauge fluctuates at times while this happens.

Are you refering to the IAT? Because the one I've got is an old B18a IAT that I cleaned with some sensor cleaner. I have no codes btw.

there is another idle adj. screw where the throttle cable sits on the throttle body...i didnt have one in and my car would idle like shit...i put that in and have had no problems...you should be able to adjust it with like a 6mm hex key

I don't think it has anything to do with the it being an OBD2 engine with an OBD1 ECU.

Have you adjusted the FITV?

You're issue seems to lie in something electronic. Maybe the IACV or the FITV or both. I know my car did the same shit and it ended up being that I was using the wrong throttle body gasket...

I'd taken both the FITV and IACV apart, cleaned and put back together. I'm using the B20 throttle body... does it have any different chamber or paths in it that are different to the b18 tb? Or because I'm using the B20 tb and tb gasket on the skunk2 im for a b18 its causing a leak of some sought? I'm pissed because my local wrecker has a b18b there which i'd love to take heaps of bits off to replace suspect parts on my motor... but they won't let me touch it!!!!

Not sure if will make any difference... but most of the emission shit like charcoal cannister and that I got rid of as part of my wire tuck.

now you mention you using a b20 tb and are you using the b20 tb gasket too or the ls? Make sure the gasket is made for that tb. Try the ls tb, wouldn't hurt to try.

Yeah... I'm using the B20 TB and TB gasket. May try an LS.

I've found someone selling an ITR TB. I don't think they have an fitv. If I were to purchase that (also using an ITR TB gasket)... would I be able to bypass the fitv all together? Or would I need to install the fitv to the ITR tb?

if it wasn't built in with the throttle body then you dont need it.

Did a self CEL test on it today (even though its not throwing a CEL) and came up with CEL 14... IACV!

This would make alot of sense. Only reason I never thought of it before was because I'd previously cleaned and replaced the original one. Plus was never throwing a CEL. Must have got a dodgy one... OR problem in wiring.

May have to do some continuity tests before getting another IACV!

change it out and see what happen