problem

[eyefi]

after an exhausting few days hitting the car with spanners i've finally finished the engine, woohooo! so, i started it on monday and it's running really rough. i pulled the plugs and 3,4 & 6 were carbon fouled, cleaned 'em up started rough ran rough for a few seconds. pulled the plugs again, same story. wideband reports very lean (expected if only 3 cyls are firing) or all over the place.

now might be a good time for some history :-

irridium plugs (came with the car)
new fuel system (aero fpr - flow tested 650's)
original coilpacks ('94 - 20k miles)
wiring & connectors look fine
new cams (cam belt)
powerfc ecu (compensation setup for bigger injectors, on all injectors)
compression is excellent on all cylinders
car ran fine at BPU before stripdown.
no stock o2sensor, ecu set to "no o2 feedback"

sounds like plugs, i have some new (copper) plugs to put in tonight. if this happens again, it's either:-

coilpacks
wiring
ecu weirdness
injector overflow
something i've done that can never be traced, ever.


does anyone have any other ideas or logical tests to get me through this as quickly as possible.

cheers.

[Fifty]

coil pack wires wud do it if you have transposed just one.

50

[Ian C]

Coil packs won't cause an idling problem unless, as Fifty says, they are wired up wrong. The wiring could be gammy to them as well, those plugs are a bugger for breaking. If it's the same plugs fouling every time then those cylinders aren't seeing spark - possibly from the coil pack plug being problematic or maybe the wiring to the PowerFC? I've no experience with the PowerFC though :)

-Ian

[eyefi]

can i just check, when RLTC is turned to the off position it does nothing at all with the injectors?

[eyefi]

Coil packs won't cause an idling problem unless, as Fifty says, they are wired up wrong. The wiring could be gammy to them as well, those plugs are a bugger for breaking. If it's the same plugs fouling every time then those cylinders aren't seeing spark - possibly from the coil pack plug being problematic or maybe the wiring to the PowerFC? I've no experience with the PowerFC though :)

-Ian

what's worrying me is that the plugs are carbon fouled (within a few seconds) not wet, so there must be a spark but a very rich mixture or an intermitant or weak spark.

i'll also try mixing the coil packs up when i change the plugs.

do i remember reading somewhere that once iridium plugs are fouled they are ruined?

[eyefi]

moved the coil pack around with new plugs and 3, 4 & 6 still get carbon. 3, 4 & 6 are the only cyls working. 1, 2 & 5 don't alter the idle when the coil plug is pulled.

so are 1, 2 & 5 sparking??

[eyefi]

they spark!

[migster]

Ok I think its a case of elimination here on the parts you have fitted :

Check cam timing and valve clearance from cam swap.
Check for even compression...the above can affect this
Check for any thing left off from changing the injectors
Swap round injectors or even swap back to originals to eliminate them
Check FPR plumbing ( correct feed and return ) as well as make sure the static presure is set corectly and the vac feed is all good.


Just generaly back track and eliminate one part at a time HTH

[eyefi]

i have 12v at the injectors with ign on.
the injectors open/close with 12v applied

[eyefi]

Check cam timing and valve clearance from cam swap.


valve clearance was spot on when fitted. timing looks ok.


Check for even compression...the above can affect this


compression is great mid 170's across the block.


Check for any thing left off from changing the injectors


allsorts has been left off the car :) all the injectors are connected


Swap round injectors or even swap back to originals to eliminate them


it's looking like im going to have to start going this far. i was hoping for some quicker less destructive tests


Check FPR plumbing ( correct feed and return ) as well as make sure the static presure is set corectly and the vac feed is all good.


FPR feeds to the side, returns from the bottom. static 36psi pump running, no engine. vac feed from the MAP sensor, all air tight.

cheers.

[eyefi]

quick update:-

i took no1 injector out just to have a look, all looked fine and tested fine, put it back. i then had a quick look at RLTC with the laptop and noticed some of the numbers seemed a bit screwy, so looking deeper and comparing to a backup of the RLTC dat the settings were totally scrambled, reference wheels were set to right front & rear???? loaded the backup dat file and fired up the car, ran on all cyls (you wouldn't believe the happiness ) its still runs shit but thats just mapping.

RLTC was turned to the off position when the problem occured so i sort of assumed it wouldn't affect anything, seems like it can. i made the mistake of soldering the RLTC into the loom when i installed it, i wish i'd put it on the plugs now.

so a couple of little jobs to do and then a load of mapping. thanks for the suggestions guys.

cheers.

[MONKEYmark]

glad you getting it sorted. you have put loads of effort into your car

will be good to see it running.

put me down for a passenger ride when its all sorted

[eyefi]

i was hoping it would be going to totb but i think i'll play it safe and leave it at home.

your welcome to a go anytime fella.