Wont Rev Over ~2000rpm

[FineLine]

Hi all,

Currently having problems with my rb25 in my 33 gtst. Engine is recently built (head to toe, every performance box checked) has been run in and has previously had a 500hp full tune on it.

However after a recent incident in overheating & slightly warping the head, we've put it back together and gone to check the tune on the rollers, and initially it was revving out fine, however it developed an exhaust manifold leak (which we found to be the stainless manifold had warped and wasnt sealing) but now the thing wont rev out, it keeps stopping at ~2000rpm. However, as soon as u start the engine and rev it, it'll rev out without a problem, however as soon as u let it back to idle, it wont rev over ~2000rpm.

We've pulled the intake system apart, put it back together, checked for air leaks and we are 100% certain there aren't any. We've swapped out the Q45 afm with a brand spanker, same thing problem is still there.

Only thing we havnt done is to save the power fc map and reset the ecu, but this is going to be done tomorrow

Any insight would be greatly appreciated, as we now have no ideas of what the problem could be, or where to look/what to do.

cheers

[KrisG]

Man that is a shame, Its awful to hear the issues you are having mate. I really hope it gets resolved soon.

[shnaped_second]

Noel your motah is shagged, give it too me

[r33_racer]

no melted wires around the turbo/exhaust area like maybe the afm wires?

Normally, not revving out is something to do with afm/computer or perhaps ignition.

Is it running alright?

[shanef]

we wired up a new signal wire directly to the ecu, and it read the same on the hand controller (voltage wise) as with the std ones in the engine bay. so no melted wires

its running perfectly. idles just like it use to, and when u can rev it out, it revs fine, no hesitation

its like its got some sort of rev limiter on it, but i checked that on the hc and it hasnt been changed since the last tune

[s13_Skyline_inside]

just a thought, simple an easy to check, could the cat be blocked, after tunin an stuff could have melted the cat, my old 180 wouldnt rev over 3k ended up being blocked cat, fueling was up the ass but it was a stock ca18 anyway just a thought

[dangerman4]

intercooler leak?

[nuclear_skyline]

I had a similar problem yesterday. Everything looked fine, AFM voltage was OK and the plug was being dicky and was ok under idle, but as soon as things started to viabrate as the revs went up it shat itself. Hold the plug when your on the dyno and see if it helps

[shanef]

turns out to be a dicky TPS

[FineLine]

Thanx for the input guys. The prob turned out to be related to the tps. We did develop a boost leak at approximately the same time due to the silicone hose slipping from the bottom of the turbo which only excacerbated the issue but it looks like its all good now.

Cheers.