Eoin Wright

It was a strange one in the end, the inside of the plug that runs to the distributor sensor had become mangled so it wasn't making any connection. I took off the cover and plugged each of the 4 wires directly to their respective pin on the plug and then it ran perfectly. 

Checked the ignition timing and it was ok, also took another look at the engine timing to make sure it hadn't slipped a tooth and it's still fine. Anyone have any ideas why it could be running like this? Still have a code 12, it's running rich on all 4 as a new set of spark plugs come out jet black after only a short time running, I replaced the distributor and rotor arm which didn't make a difference. 

The engine timing is ok but I'm starting to think the ignition timing could be out, I got a code 12 from the diagnostic test. 

Problems started after my head gasket blew out between cylinders 1 & 2 (was running perfect prior to this). Fitted a new head gasket and started it up, initial problems were the engine management light was on (code 12) and had a high idle (about 1800 rpm) but this sometimes fluctuated jumping from 1000 to 2000 every 2 seconds or so. Once the car got to operating temperature the idle evened out but still too high. 

Otherwise seemed ok with no leaks so took it for a drive, ran as normal up to 3-4k revs but it had no top end power. After a short drive I turned the engine off and started it again a few minutes later, now the idle was incredibly lumpy sometimes struggling to stay running, there was a strong smell of fuel from the engine bay, black soot from the exhaust and trying to drive had barely any power with a lot of lurching back and forth as it couldn't hold steady revs and was unable to go any higher than 2.5k -3k accompanied by a lot of pops and bangs from the exhaust.

On inspection removing the air filter seemed to fix this problem and it ran they same way as it did on initial start up. The following day when I started it up the problem had returned and was running as poorly as it had before. I then removed the intercooler piping running into the intake manifold and this reduced the sluggish, backfiring rev building but its still running very rich. I assume its a sensor of some kind that is faulty as it was running fine initially but now its choking itself with fuel. Other things to note which I don't know if relevant or not but I changed the fuel filter at the same time as the head gasket, its running a td04, decat , HKS F CON, front mount intercooler and an apexi boost controller.

Any advice would be greatly appreciated as I can't find anyone else on the forums who has had the same problem. Thanks