Rb25det Popping Sound Around 5000rpm

[O.I.C Napster]

Guys,

I got a r33 gts-t 1994 and when i put the foot down in pretty much any gear about 4000rpm my car starts popping when the revs are going up on full boost. The boost stays the same bit it feels like it surges then back on surges then back on right up to redline...

Would this be a fuel pump or maybe even coils

Im running a stock bov, fmic, cai, and a standard ecu.

Ive have it into a mechanic and they still cant seem to find anything worng with it. (maybe they not as heavey footed as me.

Mind u on 5psi it wont pop only on 10psi it will.

If any of you can lend a falla a hand i thank u in advance

Cheers Matt

[O.I.C Napster]

BTW i just had a dyno run today came back with 150.7 (stink i know) but around 125km in 4th the line dips and again at 134km it dips again then again at 148km/ph and the guy sasid he fixed it.

IM CONFUSED!!

[Cubes]

0.8mm plug gap.. if that no fix rip the center coil cover off, take the car for a spin to get it hot then come home and carefully look for little flashes of light around your coils.

If they flash your coils are nackered and u need new ones.

[rob82]

BTW i just had a dyno run today came back with 150.7 (stink i know) but around 125km in 4th the line dips and again at 134km it dips again then again at 148km/ph and the guy sasid he fixed it.

IM CONFUSED!!

Check your fuel pressure regulator has its vacuum source on. If the dyno shop gave you a printout of boost and power they would've taken it off.

[TurbostyleR]

the first thing i would do is replace the plugs and make sure they are gapped to .8mm...

then i would remove the stock bov...

[ali-turko]

no gap the plugs to .7 m i gap my mate to .8 slight improvment but when gaped at .7 the whole mis fire went away

[Guilt-Toy]

ive seen this happen as well.. .7 can also help so try that before looking elsewhere.. in my case i went to .6

no gap the plugs to .7 m i gap my mate to .8 slight improvment but when gaped at .7 the whole mis fire went away

[wolverine]

standard ecu so is sounds like rich and retard.

[O.I.C Napster]

Well i just looked at all the coils and found a little hairline crack, so i had a read of the following topic:

http://www.skylinesaustralia.com/forums/in...56&hl=coils

and wala did what it said. took the coils out looked at them with a magnifying glass and found a small crack, used pvc tape and sweet i have boost again right to redline. Maybe only a temp fix but saved me $$$ on coils i didnt really need quite yet.

Cheers for ya help

Matt

[Cubes]

And a picture of my crack.

Same place where yours was?