Has it had a new fuel filter since you've had it? Fuel blockages aren't that common on Mk2's because they have a plastic tank, but it is possible for pumps to fail. If you disconnect the main pump, you should be able to hear if the lift pump is running. You wouldn't really expect to have a fuel starvation problem sitting in traffic though. Does the rev counter behave when it's misfiring? Sounds more like an electrical problem than a fuel problem to me. Have you got a spare dizzy, TCI unit, or hall sender you could try?
i have a spare dizzy i could try but not a tci. It had a new fuel filter around christmas time. Is there any checks that can be done on the hall sender in the dizzy? The rev counter stays at around the same rpm as usual but the engine runs a bit lumpy as per a misfire.
The hall senders tend to fail intermittently, so it's hard to test for. It's worth checking the condition of the plug and wiring to the dizzy though. I've seen the electrical contacts slip in the plug and give a bad connection too. The rev counter tends to be erratic when a hall sender is failing.
Difficult one. If the lift pump stops working it makes the car undriveable. If the pump is starting to fail it could cause this problem. I think they're fairly cheap, might be worth doing to eliminate.
I've got exactly the same problem with mine (2E/PB). I know its number 4 cylinder and have a good spark so thought it was an injector problem, I'm in the process of changing that injector. Tick over is stable but sounds lumpy and when revved you can hear its misfiring and it comes and goes.
Right. I have managed to check the air flow meter resistance, this is fine. I have checked the injector resistance this is also fine. The charge rate when fully loaded and rev'd at 3000rpm is approximately 13.75v. I was going to change the dizzy tonight for a spare one I have but saw that when i removed the shield disc inside the distributor it was fairly dirty with oil and muck in it and covering the hall sender. It was also a bit dirty in the hall sender plug as well so i gave that a good clean out and it now looks like new inside, so will try this and see if makes any difference. One thing I have noticed though is that when I start and stop the car most of the time there is a metallic 'ting' sound. I located it tonight as the flap in the air flow meter moving and 'flapping' about.(no pun intended) Now its got me wondering if the spring has actually lost some of its tension or weather it should be like this? I haven't got a spare air flow meter to check it against that's the only problem.
I've never noticed that noise from an AFM, although it could be there's a bit of rubber or foam that's meant to deaden the sound. I haven't got one to check, as all my cars are Kjet at the minute.
does sound like the spring is a bit too loose in the afm, mine never made that noise that I could hear
if i want to adjust the tension on the air flow spring which way do you turn it to put more tension on it?
adjuster wheel is loaded by same spring that loads flap ie turning against resistance of spring will increase load on flap.
i tightened the spring in my air flow meter 2 notches last night and the drive to work felt better, especially when crawling in traffic, it wasn't as jerky at very very light throttle. I've also got a new lift pump and some of the correct cloth/fibre covered vac pipe on order, so i can replace all the vac lines just for piece of mind even though they look ok.
The AFM should definitely not be bouncing about to any great degree at idle or making any kind of metallic noise when you switch the car off Be aware that adjusting the spring tension and altering where the flap sits at idle will also affect the idle CO% and mixture at light throttle (up to the point the AFM is pinned open) It does sound like the flap spring was too loose from your previously excessively rich idle mixture. The longer stroke of a 2L will make it more apparent too... I would reset your idle mixture again now you have messed with the spring and see how it runs....
Yesterday morning saw the golf misfiring on idle again. I didn't have to drive very far so didn't find out if it was further up the rev range when on load. When i got to where i was going i thought i would whip the plugs out to inspect them and found that cylinders 2,3,4 were brick red and cylinder 1 was a browny colour. Any ideas??
So does the AFM flap still rattle and does it only do it when it misfires? To me the 3 brick coloured plugs look suspect, the 1 brown plug looks normal but it's hard to say from pictures. Have you gone through all the basics again? Engine and dizzy timing etc. In my experience injectors can be faulty even with a good resistance. Try and eliminate components when the car is misfiring, wiggle wiring and connectors or safely pull ht leads from plugs one at a time to see if it is one or all cylinders. Don't you just love cars!
"The following is a comprehensive list of conditions which you may find when you pull spark plugs: Signs Normal: When the engine is running the way it should, normal-reading plugs will look pretty much the same way they did when they were new and first screwed into the engine block. Normal, but with red coating: The red coating is a result of the additives in lower-quality unleaded fuel and will be visible on the plug's ceramic insulation. The red coating is not an indication of any engine problems." (taken from http://www.automedia.com/Spark_Plug_Diagnosis/ccr20030701sp/1) what kind of petrol are you using?
i've been running on a mixture of shell normal unleaded and v max and not long ago put some injector cleaner through the system. Changed my dizzy this morning but am going to change my injectors tonight as when i checked the resistance again its 5ohms across all 4 so is just on the boarder line of what the haynes manual states.
after changing my injectors the other day i haven't had any more problems. (touch wood) so hopefully thats sorted the problem once and for all.
Sounds like injector 1 then.. as the rest were all red, which indicates that 2,3,4 are getting fuel.. (Sounds like your injector cleaner additive leaving a residue). But 1 wasnt..
