Stuttering/hesitant At High Revs

[JamesK]

Hey guys i started to notice recently when i drive flat out and at high revs the car stuttered/hesitated a little i thought it was the sparks so i change the shitty ones that were in there to nice new NGK iridiums it didnt fix it per say but the problems changed now it feels like im hitting the rev limiter at 4-4.5K for a moment then goes fine again, but i havent been able to get on the freeway to really give it a go yet. Im thinking it might be the packs but i wanted to get some input before i blow a wad on splitfires, also could it be the fuel pump? Maybe ill change the fuel filter and see how that goes first

[ashneel]

coilpacks.

easy way to check is take out all coilpacks and give them a good clean. look carefully for hairline crack. usually looks like white powdery cracks. if you see then that means your coilpacks are gone. if you can do a DIY repair on them with some clean silicone sealant.

i did that to my R34 and it handled 240rwkw daily for over a year and still going strong.

[JamesK]

coilpacks.

easy way to check is take out all coilpacks and give them a good clean. look carefully for hairline crack. usually looks like white powdery cracks. if you see then that means your coilpacks are gone. if you can do a DIY repair on them with some clean silicone sealant.

i did that to my R34 and it handled 240rwkw daily for over a year and still going strong.

Hmmm that might make sense, I noticed on the 4th sparky that it was the only one covered in a small amount of white powder, I was wondering what it was but I was in a bit of a rush to get them back in so I didn't take much notice. Do you think that's the problem?....splitfires time?

[ashneel]

well it could be that or anything really. thats just the first and easiest thing to check. and if faulty cheapest to fix. try the DIY method out first or borrow somones coil packs. then if that fixes the problem you can make you mind if you should get splitfires or not.

[JamesK]

well it could be that or anything really. thats just the first and easiest thing to check. and if faulty cheapest to fix. try the DIY method out first or borrow somones coil packs. then if that fixes the problem you can make you mind if you should get splitfires or not.

Just did the whole tape DYI fix, not sure, it seems like it reduced the symptom but I'm also thinking it could be placebo effect. I didn't see any cracks or anything on my packs though....

[IOWNU]

Besides the above, also check your AFM.

[JamesK]

Besides the above, also check your AFM.

It seems to be what everyone else has though cause like a lot of people say it's between 4500-5000 revs, how do you check the AFM?

[BeEnAr]

take it off and clean it. Get the MAF sensor cleaner from Bursons etc. it works a treat!

When you say you did the Tape DIY fix, wht did you tape? If it was the coils themselves then maybe do the whole loom as well, I did the loom on mine and it fixed all stuttering issues I had, after cleaning the MAF's and doing the solder joints on them too. Oh and make sure your spark plugs are gapped down to .8mm

[JamesK]

take it off and clean it. Get the MAF sensor cleaner from Bursons etc. it works a treat!

When you say you did the Tape DIY fix, wht did you tape? If it was the coils themselves then maybe do the whole loom as well, I did the loom on mine and it fixed all stuttering issues I had, after cleaning the MAF's and doing the solder joints on them too. Oh and make sure your spark plugs are gapped down to .8mm

mmm might have to have a look into that, I only taped up the actual packs and not the rubber part if thats what you mean. I was thinking about the gap. I thought it was 1.1 for stock boost?

[BeEnAr]

nooo not the packs themselves, you don't need to tape them up. Pull the loom off (the wires with all the plugs) and check it for any splits, (mine had several and could see bare wire on a couple) then tape the whole thing up with some decent electrical tape (nitto FTW) then you should be right, if that's your problem

[JamesK]

nooo not the packs themselves, you don't need to tape them up. Pull the loom off (the wires with all the plugs) and check it for any splits, (mine had several and could see bare wire on a couple) then tape the whole thing up with some decent electrical tape (nitto FTW) then you should be right, if that's your problem

I just followed this guide

[BeEnAr]

yes, but dit you have any cracks in the epoxy or not? If no then you wasted your time. Try doing the loom as well, you'll probably find it has a split somewhere, otherwise I rekon it's dry solder joints in the MAF Sensor. Fix it by resoldering the joints Tutorial Here

[33gtst]

boost cut?

[paulr33]

yeha what mods have you got, you might be on the border line of R&R and it somes it goes over, some times it doenst

[krzysiu]

As far as I know James is still running the standard boost solenoid so boost cut is out. I still place my bet on coilpacks.

[JamesK]

As far as I know James is still running the standard boost solenoid so boost cut is out. I still place my bet on coilpacks.

Kirs is right standard boost , gonna order new splitfires I think

[JamesK]

yeha what mods have you got, you might be on the border line of R&R and it somes it goes over, some times it doenst

Borderline R&R? What do you mean by that paul?

[BeEnAr]

Have you checked your Loom and done the MAF joint with fresh solder yet? That's a LOT cheaper than new Splitfires. If it's not your coils then when you get your new ones you will have the same problem.

The above 2 fixes will take bugger all time to do and will cost you all of $5 for tape and solder a little more if you need to buy a soldering iron too but still a lot less than the Splitfires will sting you

[Owgasm]

I had this problem after a quick squirt on the track.

Checked everything, sparks, coils, intercooler piping etc.

Turned out to be the Vac hose on the Fuel Pressure Regulator, felt kinda stupid once I noticed the little hose dangling.

Chances are yours isn't this, but yeah.

Good luck.

[ali-turko]

if u wanna check your afm, i got 2 working ones you can try

and gap your plugs to 0.8mm