Problem on warm startup
 

Hey everyone, I own an 88 n/a since one year now. My problem is: I start the car, it runs great, smooth idle no hesitation when i drive. But when i turn it off, if i try to start it within the next 3-4 hours (if the engine is still a little warm) it won't rev above 1500-2000 rpm. The idle is bouncing alot. I don't know what could the problem be and i'm asking for your help.

Thanks in advance,

Alex

Does it clear up after awhile?

If not, my guess would be a leading coil heatsoaking and not working after its hot, you'd have to check spark when its acting up to confirm it

A vacuum leak is also possible

Any smoke coming out've the tailpipe?

Another good starting point would be a compression test when its warm/giving you issues

I can start/roll it once it gets cold, i haven't noticed any smoke from exhaust. It runs really great until i shut it off. I was thinking that it could be something like the IACV or AWS since i've removed the upper intake manifold not so long ago..

Did it happen right after you had the manifold off?

The problem just appeared and it ran great after the uim removal and new gaskets. It seems like it's a sensor or something

Dirty/leaking injectors, dirty/sticking BAC valve.

But with any idle issue the first step is to eliminate the possibility of vacuum leaks.