Boost cut

[andyg plym]

Anyone ?

[andyg plym]

Update : didn't test this before but the car still cuts at 4500rpm even when at idle
If I park up and rev the engine the same happens where the rev needle momentarily goes to 0 and I get a massive bang from the exhaust

I'm still awaiting a different set of chips to try so haven't ruled them out yet, still haven't had chance to see where my boost leak (if I have one ?) maybe coming from but at idle obviously it's not under load

Do we still think another problem maybe the maf ? I've wiggled and disconnected the connector etc
The car drives absolutely fine until you are on full throttle heading past 4000rpm

[prj]

Your ECU is screwed, congrats.
Needle -> 0, ECU reset.

You can try a set of chips, might cure it, but then if it was a chip problem, you should have 65535 code in ECU as well.

I'm gonna get flak for this - but this is the price to pay for experimenting and playing around. Sometimes things go wrong.

P.S.
Trigger failure can cause this as well.
Crank and Engine speed sensors specifically.

[andyg plym]

Your ECU is screwed, congrats.
Needle -> 0, ECU reset.

You can try a set of chips, might cure it, but then if it was a chip problem, you should have 65535 code in ECU as well.

I'm gonna get flak for this - but this is the price to pay for experimenting and playing around. Sometimes things go wrong.

Dimitri is everything ok mate ?

[prj]

Interesting question.

Anyway, there is only one thing that can cause this and that's the ECU resetting.
If it's always rev based, it's most likely either a fault in software, or a problem with the engine speed sensor or crank position sensor.
Can also be damaged ECU or power supply to ECU going out.

Nothing else.

[Monkeymagic]

i would certainly think this is an ecu fault of crank sensor fault.
can you watch rpm with vcds and see it also goes to zero. you might find the connection is lost at that point.
given the faults you've experienced recently i would say ecu

[andyg plym]

thanks guys, without trying to open up a can of worms- what can happen to the ecu? can parts of it burn out?

are they generally repairable? unfortunately i have no power to the obd ports still so cant check on vagcom etc

can "bad" chips screw the ecu completely?

Im using spink chips and ive heard only good things about them. I wonder if its from where I had problems with starting (remember my ecu plug thread on here) and something went wrong then just coincidentally

[4WheelDrifter]

An alarming number of people here seemed to miss the 0 rpm part. This has to be electrical, and most likely the ECU or something associated as Dmitri says.

I think the best thing to do would be to try the suspect ECU in a car that is known to run ok.

[andyg plym]

agreed stu, however theres not many down these parts!

[andyg plym]

MAJOR UPDATE:

Contacted merlins4 (aka Tristan) and to cut a long story short took my ecu to try on his car (cheers pal hope you like the wine and beer!).Both RS setup.We connected it and it drove FANTASTIC!!

Pulled to 2 bar really hard. We got back and put a code reader on it

00002
65282
65535
00255

are the codes that were stored, am I right in thinking that once ecu's are disconnected the codes get erased?
Need to check all the sensors as already mentioned on here asap, anyone know what these codes "could" mean?

[prj]

65535 - one of the chips is probably bad.

But if it works on the other car you have issues with your engine speed sensor or crankshaft position sensor or flywheel pin.

[andyg plym]

65525 when googled comes back to an airbag problem.Today I test fitted an airbag steering wheel on my non airbag car,it did have the 2 pin plug which i connected up.
But, this was obviously before I disconnected my ecu to try on the other car and now it shows up...

I thought codes were deleted once ecu removed?

[stocious]

Did you not do a clutch recently? Or was that a different car ?

Re: flywheel pin ^

[andyg plym]

Did you not do a clutch recently? Or was that a different car ?

correct i did, on this car.I did an rs conversion too.I used V stream chips but didnt rate them-very rich in running.
tried these chips and this is when the cutting started,as mentioned i have only heard good things about these current chips,and also they ran beautifully on a different car tonight.
I think its just coincidence this happened the same time

also flywheel pin, wouldnt it not run at all? mine does just fine.....until you get to 4500rpm under load or 6000k at idle

[stocious]

correct i did, on this car.I did an rs conversion too.I used V stream chips but didnt rate them-very rich in running.
tried these chips and this is when the cutting started,as mentioned i have only heard good things about these current chips,and also they ran beautifully on a different car tonight.
I think its just coincidence this happened the same time

also flywheel pin, wouldnt it not run at all? mine does just fine.....until you get to 4500rpm under load or 6000k at idle

Can't answer about the pin, but it just clicked when I read through thread that the box was off it and maybe relevant