202 not running right

[DANNY8]

This is in a HZ tunna.....but being a 202 I figured yous could possibly help.

My bro bought the ute about 2 months ago. It had been sitting for about 2-3 years, then my bro bought it. He had a qwik spin b4 he bought it and it ran fine. When he got it home it was running fine while unloading off the trailer and parking it.

Then oneday it started misfiring and popping out the exhaust, and we haven't been able to fix it. It seems to be the same cylinder misfiring, as there's no difference in duration between the misfires and pops.

It's a blue 202 with an M20. We first did the timing, but it was ok. We put new leads and a dizzy cap on, but it still didn't fix it. We were told by a mechanic that the carby was stuffed so we put another one on, nope not that either....still misfiring and popping. Today we put another head on it incase it was a dodgy valve or sumfin....but nope still misfiring and popping.

The day after it came home we gave it a service, chucked new oil, filter and plugs in. And I rekon it's been doing it since then.

The only other thing I can think of is possibly the lobes on the cam worn down (altho if that were the case, the misfire wouldn't of happened overnight)....or maybe a dodgy lifter. As it seems to have started misfiring and popping since the service I'm really startin to think it's a dodgy lifter. I guess it could have a bit of crap in it, so it ain't pumping up. Oh and the pushrods seem straight.

Any ideas?

We told my bro that when me and Brad change the motors over in PEAKN6, we'll just chuck a carby on it and put it straight into his ute. But yeah not sure yet.

[SL/ENUT]

Hmmm i was going to say the timing is up the creek but you've done all that.

Could be a lazy lifter. Might also be something electric as well.

[DANNY8]

Wat sort of electrical problem do u rekon it could be? We also put a new coil on it. Do u rekon we should put another dizzy in it?

[SL/ENUT]

Throw one in, then see if the miss is still there. It can't hurt really.

[Not_An_Abba_Fan]

Are you using the same plugs you put in when you did the oil change, you mentioned you changed the plugs then. Determine which cylinder is missing and swap plugs over and see if the miss moves cylinders.

[starfire vc]

is it running point igniton or electronic??

[DANNY8]

It's running electronic ignition. Yeah the plugs we put in when we gave it a service are still in there. If I get time 2morrow I might go over to his place and first switch around the plugs, then try changing over the dizzy.

Cheers for the help guys!

[Pub247]

haha i agree with N.A.A.F. sounds like a dodgey spark plug i remember craigvk had a similar problem a while back, new plugs but turns out one of the new one's was a dud

[DANNY8]

haha i agree with N.A.A.F. sounds like a dodgey spark plug i remember craigvk had a similar problem a while back, new plugs but turns out one of the new one's was a dud

Lol I remember that thread. I'm really gonna be pi$$ed if it's just a spark plug.....all the hours we've worked on it just to be a dodgy plug. But on the other hand if it is just a dodgy plug atleast it's gonna be a simply fix.

When we changed the heads over 2day, Brad mixed the plugs up so if it was a plug it would be a diff cylinder misfiring. But I guess it wouldn't really matter coz the duration in between the misfires would be the same.

Well let's just hope it's a dodgy plug.

[dreamcatchu]

chances are that it is a dodgy plug, i had that issue on mine after the head work, turned out that 2 of the new plugs i bought were dodgy, seems to be a very common problem lately

[Tom_1569]

chances are that it is a dodgy plug, i had that issue on mine after the head work, turned out that 2 of the new plugs i bought were dodgy, seems to be a very common problem lately

I agree seems to be coming rather frequent with new plugs. I frequently visit JC and Oldholden and i would say their has been about 5-6 cases of this in the last two weeks, most of them related to NGK new plugs.

Cheers Tom

[DANNY8]

Well I just came back from my bros' house. Put the old plugs in but didn't make a difference. Will go back in a day or 2 and try putting another set in just in case.

[Tree cutter]

Have you checked the inlet manifold to make sure it isn't burnt out where it bolts up to the exhaust manifold. There are two places where the exhaust gases are supposed to flow through it to warm it up. If it has burnt or corroded through so that your exhaust gasses are entering into the inlet ports then it will cause all sorts of problems. You could try taking one plug lead off at a time while the engine is running to find which cylinder is missing.

[DANNY8]

Haven't checked the intake manifold, but I'd say if it was that, it wouldn't be just one cylinder misfiring, it would vary...if ya know wat I mean. The manifold was off when we changed heads (also chucked extractors on at the same time) and didn't notice anything out of the ordinary.

[Not_An_Abba_Fan]

Check the freeplay of the dizzy shaft, also pull the dizzy out and check the gear on the bottom, if it's the nylon one it may be worn causing timing issues.

[dreamcatchu]

by chance have you checked your dizzy cap? could be a slight crack in it or even a bit of moisture in there

[Goon]

The settings on the carby are set for a HZ? which ist a blue 202 so it should be diff..

no leaks in the head of the exhaust anywhere?

I was going to say the head first, but you've already done that..

[DANNY8]

Yeah it's a blue 202, and we've tried playing with the carb settings. Tried 2 dizzy caps, one off a spare motor which was running good b4 we pulled it out, then tried the one off my motor which hadn't even been used until we tried it on the hz.

Haven't been back to further investigate so haven't tried another dizzy yet....that's next on the cards....oh and putting new lifters in it.

[Goon]

Yeah it's a blue 202, and we've tried playing with the carb settings. Tried 2 dizzy caps, one off a spare motor which was running good b4 we pulled it out, then tried the one off my motor which hadn't even been used until we tried it on the hz.

Haven't been back to further investigate so haven't tried another dizzy yet....that's next on the cards....oh and putting new lifters in it.

Sounds like the right moves to make, hope it all works out

[Tree cutter]

Have you checked to make sure the harmonic balancer hasn't slipped so the timing marks are out. If it has been sitting for a while there is a fair chance the rubber on the balancer has perished so the outer part can spin around so the timing mark is in the wrong place.

[commsirac]

If new plugs and leads didnt fix it, then perhaps look at the internals of the dizzy. It could be the electronic control module which is housed in the little hump adjacent to the cap. Sometimes the module can work loose and need reseating to make a good earth connection.....needs heat conduction paste. Perhaps this is unlikely since it appears to be a regular misfire in the exhaust. If you can swap over another dizzy and coil, even a points dizzy and coil and see what happens.
Ignition in the exhaust points could be due to an exhaust valve slightly open when the plug is fired. As suggested ^, disconnect and reconnect one spark lead at a time, if when one is disconnected the exhaust ignition goes away then you may have your problem.

[DANNY8]

Yeah the balancer has slipped but we chucked a new mark on the balancer where tdc is, and we got the timing light onto it again.

But yeah I still haven't been back around to further investigate, I'll still try switching the dizzy with a spare, and removing the leads to find out which one isn't playing nice.

[amen]

What carby does it have on it?

I used to own a garage and we had several vehicles with 202 engines in them and had a similar problem to yours and we found out that it was the carby.

[DANNY8]

double barrel varajet....have tried 2 on it

[amen]

Well it just about seems like you have tried everything that most persons can think of and still no success.

If it were mine, I would sell the problem to someone else and count my losses, look for something else to take it's place to do the job that it is supposed to do. LOL.

Best of luck.