Please help - I have no hair left to pull out.

A few months ago i fitted an Apexi AFC-II fuel controller. After about a week i developed a misfire. I disconnected the AFC but it was still doing it so I took it to my local tuners who said it was misfiring on all four and the most probable cause was a coil pack. So I borrowed a coil pack off a mates car but it was still doing it.

I booked it back in the tuners but by the time the day came the misfire had completly gone so i didn't bother going. A w days later it came back but a few days after that it went again.

This continued for weeks during which time i was looking for a pattern such as when it rained or when the tank got empty but there simply was'nt a pattern.

Its been ok now for 3 or 4 weeks and i thought i'd seen the last of it but it came back last night with avengence but is already almost gone.

Please has anyone got any ideas?

 

what MY?

when you say you borrowed "a" coil pack did you just get one or a set of four?

 

water getting into the spark plug leads somewhere.....engine end not plug end?

Tim

 

Thanks guys.

Sorry I forgot to mention its a UK MY98 so theres only one coilpack on these and it was borrowed from a same year car.

As regard to water in plugs it can't be cos its miss firing on all four.

I've also illiminated water in the tank.

 

could be bad fuel pressure casues by duff pump / blocked filter or something. need to get that checked with a pressure gauge.
could be blocked/sticking injectors too.
could still be spark plug leads - did you replace them as-well ?

I take it it doesnt through an Check Engine Light at any point ?

OR - where the AFC was fitted, have you re-checked the wiring is good when you took it off ? where it was fitted it could have damaged some other wiring causing the intermittant nature you're seeing !?!?!?

Steve

[Edited by ScoobyDuck - 4/29/2003 4:59:21 PM]

[Edited by ScoobyDuck - 4/29/2003 4:59:49 PM]

 

Cheers Steve....

But when it was on the rolling road it showed as an electrical mis-fire showing randomly on all four cylinders so this would surly rule out any fueling problems. To confirm this its smells really rich and flames like a good'un outta my twin back box full decat system

As for spark plug leads I have'nt replaced them for the same reason. Surely all four leads can't go at once?

Oh and no.. theres no check engine light and I know the bulbs OK cos I've seen it come on once before when playing with some wires I should'nt have been.

The AFC was fitted by myself and I checked and re-checked the wiring for damage and their connections but after re-connecting it I was still convinced this was the cause so I had it re-wired professionally when I had an Apexi Boost controller added.

One possibility I've thought about is the crank sensor, as this is presumably where the ECU gets the signal telling it which plug to fire and when. But firstly I have no idea where this is, how much they cost to replace and also I would have thought if it was gonna go wrong it'd just stop working rather than be intermittent.

Thanks again peeps.

 

Any more ideas anyone?

 

I'm now bald

 

or it could be an ecu problem not switching the coil pack correctly needs to go to the dealer.

 

doubt dealer would be able to help with all the additional goodies bolted on, as they're not gona be able to see what it's doing to the injector & boost signals

Steve

 

Many thanks Steve and Rob.

I will see if I can persuade someone to let me try their sensors out at the week end.

As for what Rob said.. it's made me think about another possible (and rather embarasing) cause... When I first started playing with the Apexi's and I was messin about with ECU wires I did'nt bother putting the kick plate cover back on. Around this time I took the car to a secluded spot with a certain female to see how comfy it was with 2 people in the passenger seat. As it was a tad chilly I left it ticking over and managed to shove my foot into the ECU causing the engine to cut out. It would'nt restart for about 15 mins and when it did it was miss firing badly for a few mins.

(Sorry.. did'nt need all the detail there but thought I'd reward you with a funny story to go with it)

Anyway Could this have done any damage?

 

onlu if the gearstick or handbrake got in the way !

you've probably got a dodgy break in your ECU wiring loom ! that's gona be a bit difficult to sus out !

 

DannyBoy',
d'no what it could be then !
when you say 'electrical mis-fire' I take it they were checking each cylinder for when a spark should have been produced from the coil pack?

the crank sensor is easy to spot - it's right under the alternator.
the other one to check/swap if you can get your hands on a mates car, it the cam sensor, which is on the right front of the block (looking from the front)
I would have thought that a dodgy signal from either of these would make it run realy rough & throw a CEL too - but maybe not!

it may still be something to do with the APexi stuff, but you might be better off getting it diagnosed with out it - might make it a bit easier (depends how hard it's gona be removing it all).

gona go dig out the diagnostics pdf & have a read .. see if it throws any ideas into my head!

good luck mate!

Steve

edit - just had a thought, as it's so intimitant it's gnoa be hard to find, but it could be an earthing problem. try checking earth straps, or making some new ones (like the DIY EARTHING MOD thread & see if that makes any difference)

[Edited by ScoobyDuck - 5/7/2003 9:34:17 PM]