Wierd Shut Down/miss Thing

[beau_32]

hey guys, got car back the other day from getting head gasket done, head had a full service and was resurfaced used arp studs and cometic gaskets (head, inlet mani and exhaust mani), gates belt, new tensioners etc etc

when i first went in to get it the mechanic said it was running shit with the boost up so he just ran it at waste gate pressure (10 psi) and said it was ok... i got in it and got 3 blocks down the road and went straight back as it was running bad, at like 4.5k rpm it would just break down and miss and carry on, revs wouldnt even keep climbing! when i got back and told him he said he replaced 1 plug but rest looked good so he didnt bother doing them, so he said leave it with him and he'l replace them all just incase its them. went there the next day and got it, still running shit and he said it mite be the remaped ecu freaking cause of the change in compression. i took it cause i had the shits and thought id sus out what i could find out, so i had a search on these forums and couldnt find anything so i look for a tuner that does 32 remaps and decided id ask toshi (from these forums also) about it and he said it mite be compression but to him it sounded like timing and said to check timing marks and ignition timing before going to see him for retune so i did that and sure as shit the inlet cam was 1 tooth out so took it back to mechanic and showed him (took photos while i had cover off) and he said bring it back in and he'l fix it... so take it back in and when i pick it up it felt heaps better but over like 6k rpm it sort of did the break down thing but no where near as bad so i sort of just thought it was cause it was only on gate pressuse and i was just freaking cause i was used to 18psi... while i was talking to toshi he also said mite be an idea to hook up car to his software and see what its doing after doing head gasket... so thought i wont up boost till we check it then il up it once i no its sweet. so hook it up and at 10psi it was sweet no issue so i only went to 14ish psi and then took it for a drive and it was f**ked again, running as bad as the 1st time i picked it up, so toshi was trying to figure it out on computer but nothing was showing up... so what do you guys this could be? the more boost the worse it is and sometimes the miss can even carry into the next gear, say if i give it abit in 3rd the go to 4th it will sometimes keep missing and then slowly level out... things iv been told to check, coils for crack, plug gap and waste gate spring incase its leaking... any other ideas would be great!

thanks in advance beau

[Moodles2]

Break it into paragraphs, and people might actually read it and help you.

[Room42]

Break it into paragraphs, and people might actually read it and help you.

I read it and I'm happy to try and help out. From that big long paragraph it seems to me that the plugs wont be gapped properly.

[-Jimmy-]

Sound's like your AFM is playing up.

[SargeRX8]

Afm, plugs, coils/ignitor.

[beau_32]

sorry moodles2...

any way i could isolate each one of these things with out the obvious of cleaning or replacing?

at least ppl are saying its nothing major (fingers crossed they are right)

thanks guys

beau

[boostn0199]

Looks like to be one of the usuals coils plugs afm or cas.

[beau_32]

I probly should have said its a 32 gts with a 25/30, holset hx35w turbo, hi flowed injectors, gtr fuel pump, z32 afm, splitfire coilpacks, external waste gate! Its a rb30e block n 96 rb25de head...

Sorry should have put this in 1st post

Cheers beau

[boostn0199]

In that case i prob would try another cas as since the problem started after head rebuild he might of dropped the cas or something. Was it just a headgasket change or was the 30 block put in now aswell.

[beau_32]

Just gasket, bought car with 25/30 conversion done bought 20mnths ago! What is cas? Sorry if dumb question?

Cheers beau

[Gerg_R31]

Crank angle sensor sits on exhaust cam

also the timing marks on the backing plate on the head are not the exact timing marks when you use a 30 bottom end with a 25/26 head. i don't know the exact spots but might suggest to get the cam timing done on a dyno

[beau_32]

Ahhh I see well thanks, mite be my problem!

You would think a mechanic would no this sort of thing though wouldnt you?

[Gerg_R31]

Depends if that's a common job to them

[GTScotT]

When was the last time it ran well?

What has changed since then? Or has it always had this problem since being built.

Is this CEFF11Es old car?

[beau_32]

yep its nic's (cef11es) old car, it was sweet before head gasket was done mate. runnung 18psi perfect, pulled like a train from 3000rpm and getting around 350ks a tank...

i gaped down plugs and checked coil packs yesty and still no good... im swaping afm with a mates on weekend and see if that helps!

ant other ideas guys?

cheers beau

[beau_32]

does anyone think it could be a fuel pressure regulator issue? its only the standard regulator???

cheers

[GTScotT]

Try the CAS.

Ive had one do something similar after it was in a front ender. The motor would actually shut itself down too.

[beau_32]

how can i test to c if its CAS? or would i just have to replace it? i tried mates AFM today and no diffrent

cheers beau

[DONO]

On 03/10/2011 at 3:33 PM, beau_32 said:

how can i test to c if its CAS? or would i just have to replace it? i tried mates AFM today and no diffrent

cheers beau

many years later and I wish this thread was finished lol, if you're still around, did you end up sorting it? What did it end up being?