Hi guys, need some advise...
Last Saturday finished doing my engine from the HG up and all seems ok. Engine runned fine Saturday night and all Sunday but two days later, when revwing normaly (no boost) in 3rd between 1500 and 2500 rmps I noticed slight misfire. Above that rotation (ie 5th, 3000 rpms, 110 km/h) it doesn't misfires.
I read somewhere that after replacing the cam belt you need to time the engine but I didn't do that. I know it coud be something else like leads (I never changed), plugs (W5DPO with 60.000kms), rotor arm, something electric...
Do you think I should rotate the dizzy a little? Back or forward?
Greets from Portugal,
Bruno
it might be the timing that needs adjusting with a timing light.
However those plugs/leads - and just coincedental that you changed head gasket.
or cambelt could be a tooth out.
sounds like you have a timing issue seeing as you said you haven't timed it up!
make sure its timed up, you could a be tooth out or more!
Quote from: PeteG40 on May 08, 2009, 02:48:18 PM
it might be the timing that needs adjusting with a timing light.
However those plugs/leads - and just coincedental that you changed head gasket.
or cambelt could be a tooth out.
The crank pulley timing mark "O" was spot-on the edge of the metal thing that's supposed to be alligned with and the "dot" mark on the camshaft pulley was also alligned on the arrow tip so they were perfectly alligned when I turned the engine by hand. No chance I missed a tooth.
I don't swear by the plugs or the leads tough...
Any more opinions?
Cheers
so your mechanical timing is good - but you need to check your ignition timing with a timing light and adjust your distributor
Quote from: PeteG40 on May 08, 2009, 03:34:57 PM
so your mechanical timing is good - but you need to check your ignition timing with a timing light and adjust your distributor
Thanks, I'll try that. The blue sender plug should be disconected right?
yes, run the engine up to temp and then unplug the blue temp sender.
If your timing is ok (which to be honest if nothing has moved on that end of the head it shouldn't be far enough out to cause missfire issues)then there's a good chance that the plug leads were damage when stripping or rebuilding, it does'nt take much to cause a small fracture in the inductor material within the lead, which typically would show up when driving the car low to mid range under load. I spent far to long checking everything and anything on my car earlier this year to find it was indeed a dodgy lead, (hmmm that rhymes). So if you know someone with a Polo thats running fine I'd check the leads by swapping one at a time(or just brrow one lrad of someone which is long enough to fit all the plugs, then its just a process of ellimination)
Well I must say that I've done almost 200 kms this weekend and I haven't got a single misfire ??? It's strange and I don't understand the pattern that causes the misfires. I though to change the rotor arm and dizzy cap for starters and went to know the price of the leads and it a fortune!!! Champion leads - 50€, FAE leads - 65€, Beru leads - 75€, Bosch leads - don't know yet! These prices are killing me LOL
Greets,
Bruno