Golf mk2 16v gti misfire shudder misfire

Hi all,

I have had a problem for sometime now when the car is misfiring when its cold and gets better when its warmed up. I have changed many items including the distributor cap, rotor arm, CSV, WUR, all the temp sensors on the side of the head, as well as having it tuned up to its basic settings. Today i took it to the garage for them to take a look, and they checked the fuel pressure which was fine and checked the injectors and changed an injector ring. They also put new leads. I have noticed that when you go along sometimes it misfires and sounds a bit rough as sorts of shudders and sort of lacks power. I have noticed that when i am doing like 30/40 mph and i put it in 4th gear the engine dont like it and sorts of shudders and sounds rough. Do you guys have any idea whats going on. I have noticed that when it behaves like this its like its only running on 3 cylinders. Its more noticeable in the morning from a cold start, and gets better when the engine warms up, but still has a slight misfire and lack of power.
Another point is i have noticed a tapping sound (tappets) will this cause this problem. The garage said that the engine is old and tired, but its only done 107,000 miles and has been looked after (FSH).

Any ideas guys to what to look at now. The garage did say that one of the cylinders has less pressure than the others (15%-20%)

Cheers, Daran

Have you checked the distributor itself?

Yes i have, it looks all good its dry with no oil. There are no oil leaks around that area. The hall sender plug had a bit of oil, but i cleared it out, i am sure that cant make the difference. cheers

And there's no play in the dissy?

Theres no play, just a bit but thats fine. The bloke at the garage was saying that the valve could be sticking, as there is a tapping noise, but do you think this would cause the problem.

That sure could be the problem if there's a valve's sticking. You'll lose compression on that bank making it feel like a misfire even though it is firing.

When started from cold, it starts up fine and idles fine. It revs cleanly, and feels that all the power is there. Its just when i start driving its very rough and misfiring. But after 2-3 mins its fine/better. But when your going along sometimes its not pulling cleanly and struggles as its shuddering, but if i change down a gear its ok, and i need to rev it high before i can change up again for it not to struggle.

I'd wait for Crasher to get on and have a read. Bit of a guru and should be able to give a definate. ;)

Thanks, I know, he has replied to my previous problems, he knows his stuff. This problem is related to a previous thread i started. Take a look at the Golf mk2 16v (1990) thread on page 2. cheers, mate

Never had a sticking valve on a KR in 20 years of working on them (that thought has just depressed me!) and a rattling top end is quite normal and at 107K it will be due for new exhaust valve guides, all the lifters and the cam to cam relay chain. To me it sounds like partially blocked injectors as they are normally well past their best at this mileage but I don’t think it is the hall sender inside the distributor as these usually get worse as the engine warms up.