Weird Idle after Turbo my BP

[Jovian2k]

Finished Turbo install, had an ECU hiccup since I am using ATX harness which I fixed after re-pinning. Finally got it started up and it runs smooth.


When I rev it, it returns to idle speed but then jumps from 1700->2200rpm every couple of seconds. Any ideas what this could be??


Thought it was related to vacuum lines but checked everything does not seem to be any leaks. I don't think idle adjust screw will fix it, nor do I think it is my RX7 VAF that I had tuned 4 clicks from baseline...

[bogaut]

i replied in your mx3 thread too, but check the bov, i bet thats the problem

[Jovian2k]

yeah let me check, it is a ebay BOV hope it's not the issue

[bogaut]

yea if its an ebay one, odds are even better thats the problem. they dont seal very well.

[Jovian2k]

Just went to check that took off BOV horn so I could cover it started it up, rev'ed it and the idle came down to normal... didn't jump as before

[atomicEGT]

yeah, knockoff Greddy valves are pretty much the worst. how tight do you have the spring?

[Jovian2k]

I loosened the spring all the way, seems very tight still. I tried to re-install it making sure it seals well and it seems to. I cannot appreciate any vaccum leak have been looking around... I would buy a real Greddy if it would solve this problem but not sure if that's it.

[atomicEGT]

yeah, pretty sure you went the wrong way with it- I think you'd want to tighten it. the springs in those knockoffs are junk though, I think sometimes they even double up on the springs and that makes them act funny. know anyone who has a legit Greddy you can borrow?

[Jovian2k]

I wish! I'm in Stratford, CT if anyone is willing to help!

[atomicEGT]

oh ****, really? your location says Brooklyn. is that thing mobile? I might be able to let you borrow one of mine to see if it solves the problem.

[Jovian2k]

Adjusting BOV from hard/soft did not change a thing. I screwed the idle adjust screw all the way tight and it lowered the RPM's down and RPM's stopped jumping! I then adjusted RX7 VAF turning it back (from 4 or 5 clicks counter-clockwise back to 0 turns) and it is idling smoothly around 1000!