Engine misfire

[jamiesgolf]

Hi guys, I have a 2.0l 8v gti which I got for £300 as it had a misfire on cylinder 4. I ran a diagnostics and it showed cylinder 4 misfire detected, and injector circuit open cylinder 4. I tried numerous fixes before giving up and taking it to a garage. They simply cleaned the injector, and changed the HT leads at a cost of £250!!!! On my drive home it was still misfiring and spluttering badly, so I opened up the engine bay and noticed the injector connector wasn't on properly so I put it on properly. I then took the car for a drive and it was no longer misfiring. I then cleared the fault codes and then went for another drive. Almost immediately the ecu picked up the misfire again even though I cannot hear nor feel it any more.

Before I took the car to the garage I assumed it had to be the injector or injector wiring harness that needed replacing but I thought id
Take it to a mechanics as they'd know for sure and I thought it'd be a cheapish fix.

Any ideas what's causing the misfire that is now unnoticeable?

Thanks for any help in advance!

[gm8]

faulty coilpack ?

[jamiesgolf]

Already changed it, and the maf sensor, and all spark plugs. None made a difference :-/ oh and another mechanic I gave it to changed the coolant temperature sensor which also made no difference

Thanks for your help

[mike1990]

Get the car scanned for fault codes and compression test it

[james2]

Hi guys, I have a 2.0l 8v gti which I got for £300 as it had a misfire on cylinder 4. I ran a diagnostics and it showed cylinder 4 misfire detected, and injector circuit open cylinder 4. I tried numerous fixes before giving up and taking it to a garage. They simply cleaned the injector, and changed the HT leads at a cost of £250!!!! On my drive home it was still misfiring and spluttering badly, so I opened up the engine bay and noticed the injector connector wasn't on properly so I put it on properly. I then took the car for a drive and it was no longer misfiring. I then cleared the fault codes and then went for another drive. Almost immediately the ecu picked up the misfire again even though I cannot hear nor feel it any more.

Before I took the car to the garage I assumed it had to be the injector or injector wiring harness that needed replacing but I thought id
Take it to a mechanics as they'd know for sure and I thought it'd be a cheapish fix.

Any ideas what's causing the misfire that is now unnoticeable?

Thanks for any help in advance!

£250 for not fixing it sucks. 

[jamiesgolf]

Yeah I've run a diagnostics and nothing new is showing up. Yeah it's really annoying, especially when you're a student! Charged me £10 to take it for a 'test drive' which they obviously didn't do as it was still
Misfiring!

[MoshiMoshi]

If they charged you for 'HT leads' I'd be suspicious. Your car doesn't have them to speak of, it has a coil pack wiring harness and coil packs that step the voltage up to generate the spark. I'd be taking it back and having words, easier said than done sometimes though!

[topher]

If they charged you for 'HT leads' I'd be suspicious. Your car doesn't have them to speak of, it has a coil pack wiring harness and coil packs that step the voltage up to generate the spark. I'd be taking it back and having words, easier said than done sometimes though!

its a 2.0 they don't have individual pencil coils, just one coil pack and ht leads.

[MoshiMoshi]

Ahh, should have noted the 2.0 in the post. Well, I'll be leaving now!