Nate

I just rebuild my b16 block with 81.25mm arp pistons and tt rods, left the head completely stock, put the motor all back together got everything in the car, hooked up and running and strted it up and its not running real well. The idle is really low and unsteady and there is a very strange supercharger-like whining sound coming from the cam gear area. I think it could just be the timing belt rubbing on something cause the sound will speed up and match the revs of the motor. Also, when I took it out for a gentle test drive it would rev over 3k in 1st, it just cut out like the ecu was just cutting fuel or something and even when I tried revving it in neutral it would do the same thing. I am still on the same map I was running before which was with stock compression and a greddy 18g turbo on 10psi with 440cc's. Im still using the same injectors as before but could the change in compression be a big enough difference to make it run this bad? Should I try running it on stock injectors and stock ecu?

sikcrx89

your cut issue is the lauvch control on your basemap. you shouldnt run the car on your basemap and injectors. swap out for your stock injectors/ecu and try that. pretty sure that will fix you right up. as far as a noise from the cam gear area it is possible its rubbing but my guess is its to tight.

Nate

Well my launch notrol is set at something wierd like 6800, I never used it anyways but could it still be the reason its cutting off at around 3k? Yeah its possible the belt is too tight but would that really make a noticeably loud sound? So even with the lower compression it should run fine on the stock management?

sikcrx89

yes thats why it cuts out is either your launch control or its just flooding the engine out. and breaking in will be fine on stock management. the belt wouldnt be as loud as you think it would be that would be the first thing i would check

SpeedyJAY

The whine you hear is most likley a timing belt that is over tensioned. Loosen the tensioner then rotate the engine around once then tighten the adjuster nut like it says in the manual.

As for your stumbling idle. Eliminate all the stupid ---- first before you start swapping out ignition/fuel ----.
My first guessed would be timing....what is your timing at?
Your timing may have changed a bit...and thrown your ignition maps to hell. Put a light on it and reset the ignition maps per what your engine timing is

Second guess would be a vaccum leak. Just start poking around and listening for a hiss.

My last build had a bad vaccum leak that caused it to run like that. Turned out to be the throttle body gasket was torn and was leaking out through the bottom of the manifold, very hard to find