ack5252

Hoping to get some help from you guys, I am banging my head against a wall on this one. I've got an AP1 that I fully gutted and built up primarily as a track car, but will see a little street use too. Got it all together and fired it up for the first time last weekend and to my surprise it cranked right up, piece of cake! Idled fine for about 30 seconds then got really rough. Tried to slowly rev it up and every time it hit 1500 rpms it would start going crazy as hell! Reving up and down, up and down, up and down, then dead. And if i give it anymore gas it dies right away too. Put a diagnostic tool on it and got the general random misfire code, as well as individual misfires in every cylinder. After putting in new gas and plugs, the indivudal cylinder misfires went away but the symtpoms remained exactly the same and I still had the general misifre. After about 3 minutes of idling the plugs were black as night and I'm thinking the ECU is causing it to run ULTRA rich for some reason. I have an adjustable FPR but no gauge so no way of checking fuel pressure which may be part of the problem. Here are some particulars pertaining to the engine:

Stock block with Carillo rods and Mahle (12.3:1) pistons. I couldnt afford an EMS right off the bat so for the time being I put in a thicker head gasket to compensate and bring the compression back down to near stock.
Supertech valves, dual springs and retainers
8.5lbs flywheel
Stock injectors fully cleaned, blueprinted and tested by RC Engineering
Brand new fuel pump and fuel delivery line
AEM adjustable fuel pressure regulator


Any thoughts from you guys on how to go about diagnosing and fixing this? I'm particularly scared/nervous about it since its a brand new motor, which further complicates things because I don't have a control reference and can't get it to rev past 1500rpms.

noodels

Careful regarding cylinder wash <petrol down the bore>and score the walls ect may also damadge oil.
would check valve timing,also get the correct fuel psi,or swap in your oem FPR

ack5252

An add-on to this, i dont have a secondary O2 sensor hooked up, aside from showing a CEL,, would that casue the ECU to do funny things?

postman

Be sure of correct fuel pressure first and foremost.

06Estukay

Sounds similar to a problem I had last year (fuelling problem, injector issues). Remove all possible variables, starting with the FPR. Swap the OEM FPR back in. After that, try a different known working set of OEM injectors. Let us know how it goes.