Tintop Misfire

[peter_m7uk]

Hullo chaps,

 

Been having an irritating misfire problem for a while and wondering if anyone had seen something similar?

 

It started a few months back when my Polo engine started misfiring under load, so I ended up renewing

the plugs, leads, coil pack, air filter and fuel filter, which greatly improved matters, but I now still have

a problem with cylinder 4 (according to diagnostics tool).

 

I swapped over the injectors for cylinders 3 and 4 to see if I had a dodgy injector, but the problem remained

in cylinder 4, so I think I've ruled out problems with spark and fuel. The car has only done 66,000 miles, so

I'd be surprised to see any compression problems. The oil and coolant are not contaminated, so the head

gasket must be fine. The problem is also intermittent, so I wouldn't imagine that it's a worn cylinder, although

it does seem more common for a cold engine.

 

Other than a dodgy loom or ECU, I can't think what else could be causing it!! I've cleared the fault in the

ECU memory several times and even disconnected the battery for a fortnight while I was on holiday, but still no joy.

 

Any help would be appreciated. Thanks,

 

Pete

[Guest Ramraider]

Hullo chaps,

 

Been having an irritating misfire problem for a while and wondering if anyone had seen something similar?

 

It started a few months back when my Polo engine started misfiring under load, so I ended up renewing

the plugs, leads, coil pack, air filter and fuel filter, which greatly improved matters, but I now still have

a problem with cylinder 4 (according to diagnostics tool).

 

I swapped over the injectors for cylinders 3 and 4 to see if I had a dodgy injector, but the problem remained

in cylinder 4, so I think I've ruled out problems with spark and fuel. The car has only done 66,000 miles, so

I'd be surprised to see any compression problems. The oil and coolant are not contaminated, so the head

gasket must be fine. The problem is also intermittent, so I wouldn't imagine that it's a worn cylinder, although

it does seem more common for a cold engine.

 

Other than a dodgy loom or ECU, I can't think what else could be causing it!! I've cleared the fault in the

ECU memory several times and even disconnected the battery for a fortnight while I was on holiday, but still no joy.

 

Any help would be appreciated. Thanks,

 

Pete

 

Hi there, I have had a couple of Polos around that year with low ish mileage, one just required a bottle of injector cleaner in it...the other I fitted a new injector problem went. Don't remember it being loads of money either...

 

Good luck...

[peter_m7uk]

Hi there, I have had a couple of Polos around that year with low ish mileage, one just required a bottle of injector cleaner in it...the other I fitted a new injector problem went. Don't remember it being loads of money either...

 

Good luck...

 

Hi Ben,

 

Thanks for the reply. I'm afraid I've already tried a few bottles of injector cleaner, also swapping

injectors between cylinders as I mentioned in the first post. But the problem stays on cylinder 4,

so it suggests that the injector isn't the problem. Interesting to hear that you also had misfire problems

on a similar model. Maybe I should spray contact cleaner on all connections and see if I can get hold

of a compression tester, just to rule that out. My MOT is due in a month, so getting a bit concerned!

 

Pete