Running on two!

[VoodooRhythm]

Hi guys, I'm getting to my witts end with this now,

A couple of weeks back i popped a boost pipe, the car lacked power when it happened but also started to only run on two. Re-attached the boost pipe, but was still not running right, got home and did a compression test,
Dry 171, 168, 144, 152 psi
Wet 187, 187, 149, 165 psi

These are a bit up from std as i'm running a head gasket 0.1 thinner then std.
Anyhow while doing the comp test i found the plugs were stupidly black and as they are about 3yrs old decided to change them.

New plugs in it idled fine, but as soon as the engine was loaded it missed just as bad as before.
Now i figured maybe a coil went down, got the engine running and dis-connected each coil in turn, pulling 1, 2 or 3 made very little difference (although 1 did make the revs drop/engine splutter more) pulling 4 almost made the engine stop. Got hold of another two s/h coils and went about swapping 2 and 3 over.
Started her up again, but no difference what so ever!!

What other things could i look at to find the fault???

Really need to get her running again as i need it to get to/from work.

[alanjuggler]

check out the PTU if you're sure it's the coilpacks. it could possibly be injectors though, so you might want to look at the dropping resistor.

not sure why a boost leak would prompt it though.

[VoodooRhythm]

had wondered about the PTU,
Iceblade had mentioned the injectors, but there is masses of unburnt fuel coming out of the exhaust and the plugs are getting very fouled, so thought there is fuel getting in, but no spark??

[Jonny Wilkinson]

had wondered about the PTU,
Iceblade had mentioned the injectors, but there is masses of unburnt fuel coming out of the exhaust and the plugs are getting very fouled, so thought there is fuel getting in, but no spark??

What do you mean by "masses of unburned fuel" ? Is there petrol coming out or smoke/soot ?

Injectors could be sticking open leading to too much fuel or it could be the ETS or lambda broken. All would cause rich running.

[VoodooRhythm]

It's white(ish) smoke that's only visible with light shone on it and seriously smells of unburnt fuel.
I've got a pre-facelift, so no lambda.
Would be very odd for the Engine temp sensor to go so wrong at the same time as the other stuff.

Starting to think it could be injector, got a 100% working PTU coming fo will try that then injector if no different.

[Jonny Wilkinson]

Have you pressure tested to make sure you got all the boost leaks ?

[skyshack]

Difference between 2 and 3 is way too much.

Check you have coolant in the rad.

[Sideways Danny]

compression results are all over the place!! Doubt it's the cause of your issue though. Battery and alternator both healthy?

[VoodooRhythm]

Battery is only a month old, I tested the alt at the same time and is good.
Rad stilol has max fluid, not used any since fitting,
Oil is still a nice black and doesn't smell of fuel.

[VoodooRhythm]

Right so I've now fitted the replacement PTU and has made it a little better than before, seems to be running on three and will idle ok, (before it had started to need a little throttle to keep it going)

Iceblade gave me some testers to check if the plugs were fireing and found that when first turning the CAS (by hand with ign on) 1 & 4 were flashing (fireing) normally, but 2 & 3 would flash a couple of times then stop.

Is there anything else spark related I can look at??

[shane_evans]

Coilpack loom could have gone brittle. i had that on my old s13 run pretty rough, once i changed it ran as it should

[VoodooRhythm]

Replaced it with another one already, so fo both to broken in the same way is doubtful.