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Car Is Hesitating

Span

By Span,
in Engines & Forced Induction

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d-brodgtst Apprentice

d-brodgtst

Posted
Posted
any ideas as to why my car would be hesitating? it happens about when the car is above 4000rpm when your foot is planted. thanks guys. its an rb25det engine

Span

go with the standard plugs first,skylines like to do this when you dont f*k off the factory boost control,computer sees extra air then says you need more fuel so you get too much and it flat spots,0.8mm gap plugs usually fixes it.start with plugs if that dont work work ur way back form there,ie nxt step coils...still check out the ecu option,it can fix a lot at once

Span Enthusiast

Span

Posted
  • Author
Posted
go with the standard plugs first,skylines like to do this when you dont f*k off the factory boost control,computer sees extra air then says you need more fuel so you get too much and it flat spots,0.8mm gap plugs usually fixes it.start with plugs if that dont work work ur way back form there,ie nxt step coils...still check out the ecu option,it can fix a lot at once

ive actually got an after market boost controller on there mate. not sure if that makes a diff.

bubba Grand Master

bubba

Posted
Posted

Is it misfiring or just a bit of a hesitation?

I had a bit of a hesitation that was fixed by fiddling with my ebc settings. Dropped the setting that it uses to hold the gate shut down by 0.2psi and the hesitation went away and is now smooth as. Basically it was bringing on boost too hard and going past the SET value momentarily.

d-brodgtst Apprentice

d-brodgtst

Posted
Posted
ive actually got an after market boost controller on there mate. not sure if that makes a diff.

do you still run a standard ecu?if so the extra airflow from the higher boost could be upsetting the ecu and messing with the mixtures,hesitation/flat spot because the ecu is pushin a bit too much fuel in for the extra air, its just one of many possibilities,most of them are mentioned in the thred anyway,i just thought id add that,simple test,turn boost back to stock then see if it still hesitates,if it does then im wrong on that part...

charlie22 Community Regular

charlie22

Posted
Posted

i had the same problem with my r34, it turned out to be the coils in my case. the spark from the standard coils isn't strong enough and when it comes onto high boost it simply blows the spark out. but are you running a high/low boost set up or just straight out 10psi?

Span Enthusiast

Span

Posted
  • Author
Posted
i had the same problem with my r34, it turned out to be the coils in my case. the spark from the standard coils isn't strong enough and when it comes onto high boost it simply blows the spark out. but are you running a high/low boost set up or just straight out 10psi?

just straight out 10psi i will wind boost down tonight and see if it makes a diff.

1SLP80 Contributor

1SLP80

Posted
Posted (edited)

Pull out your coil packs........ Its easy to do.

Undo the 8 screws that hold the plastic cover on, at the top of the engine.

Take the wired off the coil packs........ 6 of.

pull the coil packs out, and check them very carefully for cracks. I did this, and found NO cracks. I covered the underside of the coil packs with high temp (shellys roof and gutter) silicone.

Checked and re gaped plugs to .8, now the problem is no more, im running .9 of a bar too. Only mods are pod, cooler, full exhaust and pump .........

Edited by 1SLP80
Span Enthusiast

Span

Posted
  • Author
Posted

good news guys. hesitation stopped when i wound boost back. i just put it as stock again as i am selling it. running a lot happier now. took it through the revs and no problems what so ever. thanks for the help guyz

Dan

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