Hi Guys,
Posting this on behalf of a friend who has a 180bhp Anniversary Golf, we've got a really odd misfire and its nothing to do with the plugs or coilpacks as we've tried new of each. I'm usually pretty good at diagnosing these problems as I've had some big powered 20VT engines in my time, but this faults got me stumped.
Here's a scripted log of how the car behaves, noted done by myself last night;
19:49 – Car mildly warm, reading 55 on temp gauge. Seemed to take longer to start than normal, no misfire counts.
19:51 – Pulled away and moved the car 100 meters up the road, car sounds lumpy at idle however no misfire counts through VAG Com. Temp at 75 degrees.
19:53 – Again, drove 300 meters no misfires or signs of hesitation.
19:55 – Normal driving, misfire counter reading misfires on cylinder 4.
19:57 – When pulling away extreme hesitation and misfires on cylinder 2 and 4, engine management flashing.
19:59 – Pulling away, feeling of boost issues, possibly limp mode but with no engine management light.
20:04 – Excessive misfire counts on cylinders 1, 2 and 4 when accelerating.
20:17 – When at idle cylinders 1, 2 and 4 counting misfires.
20:19 – When building up the revs again excessive misfires across the board and flashing EML.
20:31 – Excessive popping and banging on run down from 4,000 rpm.
20:36 – When driving briskly home misfires only been counted on cylinder 4, untill left to rest at idle where they are again on 1 & 2.
There is no fixed EML present on dash, the car takes a few turns longer to start than normal and has an audiable lumpy idle. The wires to the coil packs seem fine, the next step is to clean every electrical plug and earth point on the car including checking the ECU for water ingress.
Other than the above, anyone have any ideas as to what it may be, I'm wondering if its possibly a cam chain tensioner failiure? But its odd that it doesnt misfire straight away and from cold runs fine. I've debated compression testing, but if there was a cracked head or low compression I can't see the misfire switching cylinders and the car running and boosting fine at times.
Any help is much apreciated!!
Posting this on behalf of a friend who has a 180bhp Anniversary Golf, we've got a really odd misfire and its nothing to do with the plugs or coilpacks as we've tried new of each. I'm usually pretty good at diagnosing these problems as I've had some big powered 20VT engines in my time, but this faults got me stumped.
Here's a scripted log of how the car behaves, noted done by myself last night;
19:49 – Car mildly warm, reading 55 on temp gauge. Seemed to take longer to start than normal, no misfire counts.
19:51 – Pulled away and moved the car 100 meters up the road, car sounds lumpy at idle however no misfire counts through VAG Com. Temp at 75 degrees.
19:53 – Again, drove 300 meters no misfires or signs of hesitation.
19:55 – Normal driving, misfire counter reading misfires on cylinder 4.
19:57 – When pulling away extreme hesitation and misfires on cylinder 2 and 4, engine management flashing.
19:59 – Pulling away, feeling of boost issues, possibly limp mode but with no engine management light.
20:04 – Excessive misfire counts on cylinders 1, 2 and 4 when accelerating.
20:17 – When at idle cylinders 1, 2 and 4 counting misfires.
20:19 – When building up the revs again excessive misfires across the board and flashing EML.
20:31 – Excessive popping and banging on run down from 4,000 rpm.
20:36 – When driving briskly home misfires only been counted on cylinder 4, untill left to rest at idle where they are again on 1 & 2.
There is no fixed EML present on dash, the car takes a few turns longer to start than normal and has an audiable lumpy idle. The wires to the coil packs seem fine, the next step is to clean every electrical plug and earth point on the car including checking the ECU for water ingress.
Other than the above, anyone have any ideas as to what it may be, I'm wondering if its possibly a cam chain tensioner failiure? But its odd that it doesnt misfire straight away and from cold runs fine. I've debated compression testing, but if there was a cracked head or low compression I can't see the misfire switching cylinders and the car running and boosting fine at times.
Any help is much apreciated!!
check the injection rail
try getting some injector cleaner in there you could always check tge pump to see if it's blocked 
