RB25DET S1 Stall&Rich

[t_blackout]

Hello,guys.

I'm one from Thailand .Now I got some more trouble on my RB25DET S1 .

Last week,I wen to made custom front mount inter cooler after use top mount for a while,and I assume that it kick the problem start.

The problem will happen when I push more gas when running to kick the turbo .Then the car will get some split which will make it don't want to rev up .It is some kind like engine stall.But when this happen and I do the double clutch it 's gone and rev fine to the redline 6900 rpm with out problem.

I try to diagnost this problem ,and it seem to ECU ,nor Clutch which is mine now a little slip away. So could you help me out Thanks every one

PS.The car is BMW E36 ,Pierburg fuel pump,Nismo Siggle plateclutch, Z32 AFM and stock Rb25DET S1 Engine .

[Cjmartz2k]

Sounds like an awesome car.

No disrespect, but I'm having a little trouble understanding exactly whats going on with the car because of the language barrier (you still type better english then some of the Americans on this board though .) Maybe you could post up a video? Also, if I'm guessing your problem right, I think it's your tune.

[t_blackout]

I will try to capture the video to help you out.

May be it is my bad in English.sorry about that .

The problem condition will appear only when I hit the street.I have itself throttle with only engine rev ,and with shift in by the jack up with stand in.It seem to be no problem.But when i hit it on street ,it is different.

when I drive normal with short-shifter ,and little gas pedal for acceleration.it can work probably ,but when I push more throttle on gas.Let 's say about 30% up estimate by AFC Neo .The problem will be happen ,and it like it start when turbo start to spool up for boosting.

The engine don't want to rev up ,but when I put more gas on it .it rev then stall down ,then rev ,then stall ,and also feel rich mixture which can tell by gasoline smell. But when this happen ,and I kick the clutch down for double clutch the engine is rev fine up to it redline with no problem.

I 'm now guessing 2 things that can be the source of the problem . 1. ECU 2. the clutch maybe the AFM to.But I have experience the past problem of the AFM in the difference way

Thanks everyone

[t_blackout]

Sounds like an awesome car.

No disrespect, but I'm having a little trouble understanding exactly whats going on with the car because of the language barrier (you still type better english then some of the Americans on this board though .) Maybe you could post up a video? Also, if I'm guessing your problem right, I think it's your tune.

I 'm try to explain it thought I will feed the video up when I can.

nice to meet you.

[mrflip69]

Sounds like a boost leak. You said the last change you did was put on a front mount intercooler, and revving in neutral or with the clutch in, the car revs fine (no load). Check your pipes, couplers, maybe the intercooler itself is bad. Hopefully it's something as simple as that.

[t_blackout]

Sounds like a boost leak. You said the last change you did was put on a front mount intercooler, and revving in neutral or with the clutch in, the car revs fine (no load). Check your pipes, couplers, maybe the intercooler itself is bad. Hopefully it's something as simple as that.

Thanks I have check it, but I will re check again

[t_blackout]

Last night,I do the intercooler pipe disasemble ,and put it back.By my diagnostic ,it seem to be fine.I 'm about to test run tonight to see if the problem has been gone ,or not.

[t_blackout]

After all,it might be the AFM,I borrow the stock one ,and interchange it with Z32 Maf .I run very well

[Darius]

You cannot use a Z32 AFM on a stock RB25 ECU. The AFM scales are much different especially at higher RPM. Put the stock RB25 AFM back on.

[Cjmartz2k]

You cannot use a Z32 AFM on a stock RB25 ECU. The AFM scales are much different especially at higher RPM. Put the stock RB25 AFM back on.

Agree. I guess I missed where you said you were running a Z32 MAF. You can't do that with out some way to tell the computer what's going one i.e. power FC, SAFC, ROM tune, etc.

[mrflip69]

Let 's say about 30% up estimate by AFC Neo .

[t_blackout]

You cannot use a Z32 AFM on a stock RB25 ECU. The AFM scales are much different especially at higher RPM. Put the stock RB25 AFM back on.

Agree. I guess I missed where you said you were running a Z32 MAF. You can't do that with out some way to tell the computer what's going one i.e. power FC, SAFC, ROM tune, etc.

I have run it for while with no problem ,it is just some rich mixture that will be make you backfire,but now I put the stock one back on,and it is ok now .

Thanks all

By the way run with Z32 maf are seem to be good ,as it make turbo spool up faster about 2500 RPM to kick in

[Cjmartz2k]

You need to research what exactly changing your MAF does. Using a Z32 MAF instead of the stock MAF will simply allow you to measure more air before it reaches it's maximum of 5 volts *IF* you have a way to tell the ECU it's using a different MAF sensor. If does nothing performance wise AT ALL by itself. Exactly the opposite actually. With out a way to tune your car to account for the Z32 MAF, you are only confusing your ECU and you are lucky it ran at all or didn't blow up. The MAF did NOT cause your turbo to spool up quicker, unless your tune before sucked and the MAF change just accidentally created a better fuel/timing curve in that part of the map. I think that is not very likely.

[t_blackout]

that is interesting,Thank for more info on the Z32 Maf.

I ran it for 3 months with AFC neo tune put 2 in out 5 and with the curve fuel with the higher timing ignition. the reason I told you that it spool up quicker is truth ,with out it by the top mouth turbo spool at 3200 RPM ,but with this that came more exhaust ,and heating thermo .it make the push start at 2500 RPM and max boost 0.5 Bar at 3200 RPM

That is what I do here.

[Cjmartz2k]

Well, an AFC is a way to correct for the different input from the Z32 MAF. That's what you need. I thought I asked earlier if you had something to tune with and you said no, but maybe not. Anyways, glad you got it fixed.

[t_blackout]

it is my bad.Sorry for that. I tune it with AFC ,but it still come with rich mixture.

Anyway,this may not finish.I am found that the ECU may the source of the problem which is mine is currently with P6 ECU.

I disassemble it case,But everything seem to be fine ,but it could be the ECU are broke by it life time.I will get some another ECU to try it up.

Last night while I driving after test run it is suddenly shut me down on the street.I am tried to fire it up.All thing is response Fuel ,Air ,and the plug ,but no running.I attemp many time then I wait uo for 5 minute then start again.it run but after run for a while it came to shut me down again.

I restart engine about 5 time to get me home,but after last time it seem to no problem.There is no abnormal to mechenic system,so I guess with my specialist it must be the ECU.