MISS FIRE

[dumbnut]

I haved changed the ecu relay, coil, temp sensor and still no change. I have also looked through most of the forums and this seems to be a comon problem but know one seems to have said how they have cured it. Oh and i have checked all the earths.

Looks like some lost 100 quid
some one must have the answer??

[javalin]

what plugs and leads are you using?

[Khare]

It's going to be 1 of 2 things. If I'm right, I should get a free cookie.


1. Ignition coil

2. Moisture around the distributor cap. Has it by any chance got a black plastic cover around it? If so, bin that plastic cover and have just the distributor cap. Moisture gets trapped in between the cap and the cover and causes arching of the spark. I had this yesterday but quickly sorted it when I removed the cap, removed that black plastic cover, thoroughly dried the outside of it, cleaned the contacts up with some sand paper (including rotor arm), and dried the pins where the HT leads connect to as well. Fitted it all back up, sprayed WD40 on the inside of the leads and all over the cap and pins and voila, like new 

[Leon27]

what plugs and leads are you using?

Good question there.

And what Khare had done to check your arm and cap? Are they in good condition?

If you can, get VAG-COM setup and check the status' of the major bits and when the fault occurs read off whats going on.

Example would be Measuring Block 003 which gives the Throttle Position. Mine used to go up from 0 degrees to 13, back to 0 then start again at 18 up till 72. Faulty and a new one from VW was £96. Can try unplugging the TPS to see if it makes a difference. Would depend though on how harsh is your misfire? Does it feel severe like one cylinder is down or like a mild stutter?

My alternator was overcharging causing a mild stutter misfire type fault from just above idle speed to 4k rpm, your description of the fault sounds quite similar to what I experienced - Check the voltage of the alternator with a Voltmeter but ideally with VAG-COM when driving.

Also check your Vac pipes aren't kinked or knackered especially the one to the fuel pressure reg and to the ECU.

Try that and let us know how you get on

[dumbnut]

This where i am at. i took your advice and removed the black cover over the dizzy cap but it still has not cured my problem. As i fitted a second coil i have now sorced a third and that has not cured my problem.
Its showing no faults on dio.
 I have one thing left to try, i have managed to get my hand on a throttle sensor which should be here in the next few days.
I am pinning my hopes on it being that. 

[harlemex]

I haved changed the ecu relay, coil, temp sensor and still no change. I have also looked through most of the forums and this seems to be a comon problem but know one seems to have said how they have cured it. Oh and i have checked all the earths.

Looks like some lost 100 quid
some one must have the answer??

Len now owes me a the tidy sum of one hundred quid. 

[Bellend]

Could be so many things.

Can you tell if it's an igntion misfire or what?

I find on roadtests that if it's a failing lead or plug it's a very harsh missfire, whereas say a temp sensor has gone, milder missfire and rough running in general.

[dumbnut]

Its more of a missfire and a jerk when you press accelorator very gentle. if you rag the granny out of it drives without fault. travel at 30 pressing down gentle it starts to play up and it does this all the time.

[Leon27]

Fuel pressure problem? Impossible to diagnose on the net but just a thought, if its sort of kangarooing (fuel starvation?) and then the jerk could be fuel cutting off or suddenly coming back? Hard to establish but I've read that you haven't replaced your fuel pump relay. Donor one if you can, but they too are as troublesome as the ECU no. 30 youve changed.

Worth a look to check that your throttle body is clean too.

[dumbnut]

my throttle sensor came today so will be fitting tommorrow. i will give the throttle body a good clean if that dont work i will try the fuel route. I will let you know how i get on. all this has started to cost a fortune