I new in this forum... hope u guyz can help solve my problem. A little bit of me car's background: Currently I've implanted RB25DET ('96) to my 91 Cefiro (A31). I've changed the intercooler (the piping is 3"), the turbo is as big as TD06, SARD air intake, HKS EVC 3 boost controller, Apexi AFC (the 1st gen Ver.) and a customized 3" exhaust system.

My Problem:

When I rev my car to more than 3,500 rpm the engine stalls when I change gear (that is when it is in free gear after I've rev my engine - or when I change gears slowly). But the funny part is - if I don't rev my car, the engine won't stall. So I'm actually thinking whether it is vacuum problems... or is it the air flow sensor is faulty... I really don't know... I hope u guyz can give me some idea on how to solve the problem? The local mechanic has no idea what is happening...

Thankx!!!

 

I think you are right with the vaccuum problems because if it had something to do with the MAFS or with you car not getting enough fuel or air you would see the gauge (that i am sure you have air/fuel) go lean or rich. Check the vaccuum lines and get back to me.

 

Thankz for the feedback... I think I will go check it... I'll get back to u after I rectify it... Thankz...

 

I found that my intake manifold is not tighten properly... there is a gap between the engine block... that is roughly 3mm wide... and the gasket between them is kinda loose.... do think this senario may cause the engine to stall... ?

I've checked the vaccuum lines... and everything is in order...
Pls give me some advise... Thankz...

Later I will post a photo of the manifold....

 

maybe u should get a new gasket and replace it? just in case

 

Yea tighten the manifold back down and get a new gasket or figure out a way to close it up and get an air tight seal.

 

DUCT TAPE!
In all seriousness, that might the problem. When youre in gear and theres a positive MAP (manifold absolute pressure) it wouldnt be an issue. but when you shift, and your throttle closes, all that MAP would leak out of this..leak. Lol, ran out of words. New gasket, retorque, silly puddy, etc should fix it. Keep me posted.

 

I got everything changed... new gasket and stuff... checked everything and still the problem is still there... I've discovered something... I think my engine is running without a throttle sensor... the sensor is there but there is no wire connected to it... darn... I just got this car and it seems that everything is missing... hahahaha.... yeah... I wish I got a million dollars...

The wiring is "bad"... I guess i need to find a whole set of RB25Det wiring... does the RB25DET engine wiring the same as the RB20DET wiring? Cause is kinda hard to find stuff for RB25 in Malaysia... *sigh*.... anyways... thanks for all the feedback... CHEERS!!!