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Fuel cut(?) / cutting out on boost


Homer

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Guest any4any

this is PowerFC ECU Cuts

some sensor damage cut the ecu , check all sensor plugs … if ok

crank , cam , etc sensor

or you fuel pump is poor

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this is PowerFC ECU Cuts

some sensor damage cut the ecu , check all sensor plugs … if ok

crank , cam , etc sensor

or you fuel pump is poor

 

Ok... if you say so.

Where are al the difrent sensors lokated? can some one send a link to a scematick (i think its cald that. = drawing.)

 

Thanks a million!

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Have you tried swapping out known good coil packs? Not the connectors, the packs themselves? I had a 'mare with them when I went single and they seems to get worse exponentially faster as they break down.

 

Thanks Ian, this is exactly what we are planning next. Just got to find a set now!

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  • 2 weeks later...

Update:

 

Coil packs were swapped with a known good set (Thanks Steve!), but the problems persist the same as before.

 

Rob says it can be quite intermittant. Some days he can drive the car hard and it's fine, other times (well most of the time) it has the misfire/cut appears when it's on boost.

 

He also said the problem seems worse when going through 1st, 2nd 3rd, but happens less as the gears go up.

 

We're a bit stumped where to go now... :(

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  • 1 month later...
mine is all sorted homer:)

 

it turned out mine had somthing turned on the map/ecu from when it was an auto, it was retarding the ignition thinking it was about to change gear :rolleyes:

 

Mine is an auto BPU TT with the stock ECU and is doing the same thing! Can i alsow switch och change that thing you did on yours, or did you fix yours via a aftermarket ECU/Piggyback?

Need help, i whant to fix this so i can sel the car.

 

 

Best forum!!

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Update:

 

Coil packs were swapped with a known good set (Thanks Steve!), but the problems persist the same as before.

 

Rob says it can be quite intermittant. Some days he can drive the car hard and it's fine, other times (well most of the time) it has the misfire/cut appears when it's on boost.

 

He also said the problem seems worse when going through 1st, 2nd 3rd, but happens less as the gears go up.

 

We're a bit stumped where to go now... :(

 

Mine acts in the same way!...

I think on cool nights mine dosnt lose power, i know it hasent done it evry time, i just cant seem to remeber when.... caus car acts normal and i dont think about it:(

 

Could this be of any help? Could this be a clue to salving this problem? Does the engine temp has anything to with the missfire/cut? (im runing with stock SMIC) I wil leave it up to those who understand engines....

 

sorry for my bad speling (S)

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  • 1 month later...
  • 2 weeks later...

Just had a nudge to post an update on this...

 

 

Lee P took a good look at Rob's car a few weeks ago and I don't beleive found anything wrong with it.

 

Ryan then noticed that the injectors were shutting off completely at random times. I've not spoken to Ryan to get the full details, but from what Rob mentioned it sounds like Ryan made some changes to the closed loop settings on the map which has now cured the issue. I don't believe Rob's had any more issues since.

 

Hopefully Ryan will update the thread, but I beleive he thought there may be a small problem with the injector control on the ECU causing it to shut the injectors off, the changes he made worked around it (somehow!).

 

Sorry for the non-technical explaination

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I have found this when sups are low on fuel, if you accelerate hard, it dropps fuel pressure (sucking in air) and cuts out hard as if it was std fuel cut. Maybe this is a safety setting programed in the ecu, because it doesnt give the feeling of a missfire, with other cars you'll get a slight misfire but with these they just cut. My theory with your issue is may be a WEAK PUMP, so under boost it cannot supply enough pressure, the ECU recognises this and completely cuts fuel in order to stop any damage occuring to the engine....

 

The ecu may recognise this via engine the knock sensors if it doesnt measure the o2 output first.

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Just had a nudge to post an update on this...

 

 

Lee P took a good look at Rob's car a few weeks ago and I don't beleive found anything wrong with it.

 

Ryan then noticed that the injectors were shutting off completely at random times. I've not spoken to Ryan to get the full details, but from what Rob mentioned it sounds like Ryan made some changes to the closed loop settings on the map which has now cured the issue. I don't believe Rob's had any more issues since.

 

Hopefully Ryan will update the thread, but I beleive he thought there may be a small problem with the injector control on the ECU causing it to shut the injectors off, the changes he made worked around it (somehow!).

 

Sorry for the non-technical explaination

 

Was a corruption in the overrun fuel cut strategy on the powerfc. Had to turn it off fully in order to stop the random cuts which were not being trigered off any throttle movement.

 

Ryan

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Was a corruption in the overrun fuel cut strategy on the powerfc. Had to turn it off fully in order to stop the random cuts which were not being trigered off any throttle movement.

 

Ryan

 

and all this time i thought it was on a std ecu....

 

Oh Ryan, i just remembered, on my E30 with the AEM if i full throttle quickly sometimes it goes to accellerate, the completely cuts and then comes back on again, only if i floor it quickly at 4-6k rpm or so, any ideas???

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and all this time i thought it was on a std ecu....

 

Oh Ryan, i just remembered, on my E30 with the AEM if i full throttle quickly sometimes it goes to accellerate, the completely cuts and then comes back on again, only if i floor it quickly at 4-6k rpm or so, any ideas???

 

Sound like boost cut mate. It will be where the closed loop boost control is not reacting quickly from where the boost comes in so hard at higher rpm. Give us a ring next week and were sort it bud.

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Was a corruption in the overrun fuel cut strategy on the powerfc. Had to turn it off fully in order to stop the random cuts which were not being trigered off any throttle movement.

 

Ryan

 

Ryan: What would it be on a standard ECU - BPU.TT car?

Thanks.

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  • 1 month later...

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