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Almost Stalling On Acceleration

SECURITY

By SECURITY,
in Engines & Forced Induction

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SECURITY Grand Master

SECURITY

Posted
Posted (edited)

when i go to accelerate from either a standing start or between gears the car hesitates, goes lean and kind of sputters a bit then goes back to normal. if i accelerate SLOWLY it doesnt do it, and when i accelerate HARD it doesnt do it, im not sure what it is. i tried checking for leaks in the vac/cooler system with no luck.

i took a vid to see if it would help identify the problem. the gauge on the left is the wideband and you can see the pressure/vac/accelerator position on the gauge on the right.. turn up your volume so you can hear what the car is doing.

http://www.youtube.com/watch?v=xPHSLI50Kd4

cheers guys

Edited by SECURITY
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DRD-00F Grand Master

DRD-00F

Posted
Posted

well unless he has wired the wideband backwards or some crap, it's definately going lean...

It is a tough one! Maybe there's a small block in one of the injectors? Or the pump isn't getting enough voltage or something? Other then that... I was thinking a stuck throttle body but that wouldn't lean it out...

SECURITY Grand Master

SECURITY

Posted
  • Author
Posted

sorry, shouldve given a run down on the car

its got a vipec ecu, it does it under any load, i tried changing the tune around (the vipec has a 1-100 range) i went from 42 in the cells up to 60 and it didnt change much, im pretty sure its a mechanical issue.

GTR-32U Mentor

GTR-32U

Posted
Posted (edited)
well unless he has wired the wideband backwards or some crap, it's definately going lean...

It is a tough one! Maybe there's a small block in one of the injectors? Or the pump isn't getting enough voltage or something? Other then that... I was thinking a stuck throttle body but that wouldn't lean it out...

My mistake...I didnt see the AFR ratio thing on the left...Definately sounds like some kind of fuel issue. Highly doubt its ignition ( although I could be wrong )....Has anything been done to the car recently ..like prior to this problem occuring ?...Maybe a vacuum line got knocked loose

Edited by GTR-32U
SECURITY Grand Master

SECURITY

Posted
  • Author
Posted
Not sure about the vipec ecu but I had a similar problem on my VH41de safari running a link ecu, it turned out to be an acceleration enrichment issue.

i think you might be on to something, ill have a play around with the accel enrichment tables and see where it gets me.

STATUS Grand Master

STATUS

Posted
Posted
when i go to accelerate from either a standing start or between gears the car hesitates, goes lean and kind of sputters a bit then goes back to normal. if i accelerate SLOWLY it doesnt do it, and when i accelerate HARD it doesnt do it, im not sure what it is. i tried checking for leaks in the vac/cooler system with no luck.

i took a vid to see if it would help identify the problem. the gauge on the left is the wideband and you can see the pressure/vac/accelerator position on the gauge on the right.. turn up your volume so you can hear what the car is doing.

http://www.youtube.com/watch?v=xPHSLI50Kd4

cheers guys

accel pump adjustment

SECURITY Grand Master

SECURITY

Posted
  • Author
Posted
this car has not been tuned yet has it?

not properly, i had it on a dyno after the engine was rebuilt by the engine builder but the new injectors and plenum havent been tuned in properly. i got it running pretty well using the auto tune and the m5, but this problem just started randomly though.

the accel enrichment didnt work. it didnt change at all. i think its something mechanical rather than the tune.

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