Not Another Problem! Dies on WOT

[robbo_yobbo]

well, Ive swapped motors (vct 6 - and almost everything else for that matter) and have encountered problem after problem, and so far its just all been coincidence, but hopefully this ones the last prob (once the new alternator goes in).

I sit in the driveway, put the peddle to the floor and it dies for a second or so, stutters, then revs up like its supposed to. sometimes theres a little pop almost like its backfiring, but its not on gas!

accellerate gradualy, and theres no problem.

whats the likeley culprit? Map sensor? TPS sensor? blocked injectors? some other wiring problem?

None of the above realy makes sense to me, as if it were any of those I would have thought the stutter would be continuous, but its only at WOT, then goes away after the first second.

There is a loom I found on the PCM wiring harness that doesnt seem to match up to anything on the engine side - its square and orange - Anything to do with it? Anyone know what it should be plugged into?

There was no problem before I swapped motors, so is this another coincidence, or what have I screwed up?

[Mr Hardware]

you should take all that cash you found and pay a mechanic to fix it

[robbo_yobbo]

that cash was spent a long long time ago. mechanics Im sure would charge alot more than $400 odd just for the time involved in problem diagnosis and thats without actualy fixing it. it hasnt lit up the check engine light so pressumable hasnt thrown a fault code.

[Oo_xrsx_oO]

Sounds to me like you need new leads, probably wouldn't hurt to do the plugs at the same time.

[robbo_yobbo]

Originally Posted by Oo_xrsx_oO

Sounds to me like you need new leads, probably wouldn't hurt to do the plugs at the same time.

REALY!
Now thats a symptom I wouldnt have put down to leads - and if it is the case, deffiniteley another big coincidence. Plugs are only about 5-10,000 clicks old.

Not denying the possibility - but definiteley curious as to how bad leads would only cause the miss at WOT and not any other time??

Something like poor spark + WOT = rich mixture & missfire???

[5tumpy]

I second that xrsx... Sounds like spark issues to me...

[AWD Chaser]

leads, sparks, or fuel filter... I would recommend fuel filter...

[Mechan1k]

How old is the coilpack and what condition is it in?
Over time these can break down and you may find that one or 2 terminals aren't in the best condition.

Had an issue with mine where I had the odd missfire ... but no code at all (not even a coilpack code) ... removed the coilpack and one terminal was damaged on the top and scratched badly with chuncks out of it. Got a replacement one from the wreckers and has been working fine since (that's after replacing plugs and leads as well at the time ... but not fixing the misfire.

[robbo_yobbo]

Well, the problems solved - !!! it appears the problem was not as much of a coincidence as I thought - it was related to my alternator problem (which surprisingly turned out to be working anyway - only in reverse!!!!).

The low voltage must have peaked (a LOW spike) as the the alternator speed increased - because it was working in reverse, Im guessing it either confused the ECU or just didnt have enough juice to create a spark.

Either way, its all fixed and didnt involve buying anything, or spending money! - I love it when that happens (not the problems - the free solutions)!

Cheers for the tips anyway, at least Ill know what to look for if I get those symptoms again and its not voltage related.