Running on 3 cylinders

[Hypnotik]

I can't figure this **** out.


Last weekend I went out for a short drive and coming around a roundabout I got into and it dropped a cylinder. It has done this before about 6 months ago. I remade the coilpack harness and it has been fine ever since. This time, I figured out which coilpack wasn't firing and unplugged that injector to limp it home(about 1.5 miles). I started swapping around coilpacks once I got home to figure out if one was bad. #2 cylinder isn't firing with different coilpacks in it. Not a coilpack problem. I changed plugs, tried 3 different brand new ones. Not a plug problem. I thought it might be the harness again. I bought a new harness and put it on today after the car has been sitting for a week, no change. I stripped back the main harness where the coilpack subharness plugs into, no melted wires, no kinks, plug seems to be fine. When I pull out the plug from #2 it has fuel on it and I did the screwdriver trick on the injectors and they are all clicking normally. In a move of desperation I pulled the mounting bracket off of a spare ecu I had and mounted my PFC like the stock ECU because some **** on Google said it needed to be grounded and it magically fixed someone else's car who had the same problem. No change. I pulled the coilpacks out and put sparkplugs in them and laid them on the intake manifold as I cranked. ALL the plugs are firing, but when I put them back in the motor still no #2. WTF.


Does anybody have any suggestion at all? I can't think of anything else.


My only other thought is this. About 3ish weeks ago I fixed some bare wires on the harness that goes over the driver side wheel well. The car was fine for at least 2 weeks before this happened. It doesn't seem like these wires would affect the coilpacks and only one at that but anything is possible I guess...

 

[sliding-r]

Compression test it...
Cause if it sparking and fuelling the only other thing it can be is loss of compression surely

 

[DeanS15]

I'd say comp test it too... Did the plug look ok - any oil on it? Do you have any excess smoke out of the exhaust?

 

[Hypnotik]

I did a compression test yesterday, time to rebuild with forged internals.

#1 = 145
#2 = 40
#3 = 160
#4 = 155

 

[meddler]

That would do it every time.

 

[JaseYpk]

I did a compression test yesterday, time to rebuild with forged internals.

#1 = 145
#2 = 40
#3 = 160
#4 = 155

wow! thats quite a drop! would be interested to know what the cause is once you strip it down!

 

[Hypnotik]

What's funny about all this; No smoke, no noises, no water in the oil or vise versa, no oil on the plugs. The car still runs perfectly fine but it sounds like a Subaru.

 

[DeanS15]

Maybe not gasket... Maybe valve related?

 

[JaseYpk]

Mine was running on 3 cylinders after i almost flooded the engine with dirty water, but my problem was obviously water based as once i'd stripped the inlet mani and plenum off and dried and cleaned it all, it ran fine. Maybe worth a shot if you've got a spare weekend? just a good old clean out?

 

[Hypnotik]

I found the problem. Both rocker arms broken on #2.

 

[martinbattye]

that engine is filthy!!

Bee-r on there?? or just a rev limiter whore?? lol

 

[spoonman]

oops..... RAS aren't full proof are they, now comes the bit where you have to try and find all the broken bits, and martin's point freakin black in there.

 

[meddler]

That's nasty. It's not often rocker arms break.

 

[JaseYpk]

niicee... least you've found the problem. hope you get it fixed soon

 

[Hypnotik]

It's fixed. I had spare rockers and shims from another head.

 

[s15wideass]

excellent!!! i had the exact same problem with my spec r, and like you it wrecked my head for a full day (today actually) of testing wires in the loom, swapping plugs and coil packs and ended up getting sick of it, couldn't get #2 to fire.
so i had a look on here after i gave up on it and saw this thread, went striaght back out to the shed and RIPPED off the rocker cover to find the exhaust rocker arm sitting out of place under the cam shaft, not broken but out of place, just the........i'm not a mechanic so just the little thing that sits on top of the valve and keeps the rocker in place is broken so i'll have fun finding the missing piece of it in the engine somewhere.
thanks for posting this up man, saved me alot of time and head scratching:thumbs: