Boost pressure

[newsh]

Boost pressure

Most original coils are past their best. Could be a POS problem too.
If it was a MAF or boost leak or an overboost problem you would get a total fuel cut, this is not like a "machine gun"misfire at all. You basically go from full boost to nothing at all and nearly head butt the windscreen.

So I suspect a poor coilpack or POS and the boost is drowning a plug or two and unburnt fuel goes into the exhaust and ignites there.

[macspring]

I know nothing, but I'm on here since '05, and so my amateur opinion would be the same as Newsh stated that the oem coils may well be past their best.

While the oen ones look better with the 'lid' in place, the TSFI ones work a lot better, notwithstanding the dwell 'issue'.

Buy Beru ones, I've found them good and competitively priced.

Be sure to post the cure to this thread in due course.

Best wishes.

[paulmac]

I will try pos next I hope it's not the coils as I have swapped the complete coil set up from my aan engine ,but who knows they might also have issues
Ur spot on about the missfire it sounds like a machine gun but doesn't fire u in 2 the windscreen or anything like that at nearly always happens when coming on to full boost ,say 25-28 psi at 3500'rpm

[Michael S2]

If your AAN set is old as well they are likely to have problems too.

I had this exact issue of machine gun fire as you say when coming on full boost. Changed all my coil packs and problem has gone.

[newsh]

Set of red coils and a loom from Alex may well sort it.

[paulmac]

Thanks for input guys it always helps when someone has had a similar problem otherwise its very hard to know what direction to go in

[paulmac]

So I'm getting Alex to make me a loom up and will get coilpacks ordered Monday
Hopefully this will sort the missfire
Any ideas on the non idle issue or what is the downside to leavening ISV. Valve disconnected

[tomwood_uk]

Sounds like an overboost cut to me. Does it feel like its going to throw you through the windscreen when it happens?

[paulmac]

No nothing like that more missfire and I can sort of feather the missfire with the throttle alittle

[tomwood_uk]

No nothing like that more missfire and I can sort of feather the missfire with the throttle alittle

Ahh ok not that then

[eyale24]

Check the blow off valve! Maybe it full boost the piston coming up . Try to put it overwise and check it.

[Rikki Kitto]

I had similar issues updated to new coils and loom conversion sorted it right out

[paulmac]

I hope so cause I'm running out of ideas, thought I had had found the culprit last night was doing a fuel flow test suggested by Paul nugent and I heard a rattle inside the fuel pump relay pulled it apart and low and behold one of the contacts is missing and relay is in bad shape
On the up side my car now idles cold or hot , as before I had to disconnect the ISV altogether to make the car drivable ,so if any one is having idle issues may I suggest trying a fuel pump relayimage.jpg

[rs200]

well I had a same problem on AAN engine before few weeks ago.. the problem was in bad ECU because ISV stay open at idle and engine get too much air .
there was no regulation of ISV . on conector are 2 wires i get +12v on one and ground on other, just like on bulb ! :/

Iv change ECU and engine run perfect right now on idle.

[newsh]

I hope so cause I'm running out of ideas, thought I had had found the culprit last night was doing a fuel flow test suggested by Paul nugent and I heard a rattle inside the fuel pump relay pulled it apart and low and behold one of the contacts is missing and relay is in bad shape

On the up side my car now idles cold or hot , as before I had to disconnect the ISV altogether to make the car drivable ,so if any one is having idle issues may I suggest trying a fuel pump relay[ATTACH]63212[/ATTACH]

Good find, never seen that before.
I had my fuel pump fuse get so hot it melted, I've relayed it straight from the battery now, runs much better and seems to have sorted my occasional pinging issue.