Idling problem

Check fuel level in the float chamber. Might be too low.

Jan

How do I check it? And what level should it be at? And how do I adjust it? Thanks,

--Dan E

Check fuel level in the float chamber. Might be too.....high.

Seriously. Minor flooding becomes apparent at idle where at highway speeds the consumption is enough to mask it.

Can be caused by float needle valve not seating or not screwed in tightly. The 28 carb is less affected by fuel boiling (is it hot where you are?) but a possible. Probably not fuel pump pressure (if stock).

Any chance of vacuum leaks? Richen the idle mixture slightly and see if that solves it.

Speedy Jim

I'm not as familiar with the 28, but later carbs have a fuel level ~3/4" below the rim. Measure that with the top off and the float in place. I'd be very surprised if it is off and even more surprised if it materially affected idling. It's adjusted by adding washers under the needle valve.

Since you did replace the manifold seals, they are a prime suspect. It's not unusual for new seals to leak a bit. That can create enough of a leak to upset idle mixture. Spray around them with solvent and see if RPM changes.

Speedy Jim

I did that and no difference in idle speed. I did go ahead and replace the float needle valve with another original one. I did notice that there was gas in the bowl and the float was all the way down, in other words the float was not floating cause there was not enough gas. That did not seem to make a difference. I also let the mixture scew out more, about one complete turn and that did make a difference it seems to idle better for the moment. When you turn the mixture screw out does that richen or lean out the mixture? I can never remember.

--Dan E

Screw out will make it richer. The float should definitely float...high enough to have tripped the needle closed. If the new needle didn't fix that then there is still a problem.

Jim

Then I'll have to pull the top again and check it. Maybe the pump is bad but its odd that it doesn't shop up at speed...

--Dan

Yes, I agree about the "at speed" part. Another puzzle... Jim

It's been a long time since I worked on a vw but I remember it is too easy to just turn the fast idle or mixture screws to get the thing to run ok. Make sure your gas cap is vented I think that car uses vented cap. If you hear a whoosh when opening cap could be problem, just try running it with the cap loose (tank not full!) Another thing I've done before but not on that carb is monitor the float level with a light weight piece of *clean* broom straw- just drop it down that angled breather tube at the top of carb to find the relative position and mark it with a pen- (if gasket not in the way). The level should not drop at all. I would verify you can do this if you take the top off. Be careful you dont ruin the gasket looking back inside 500 times like I always do. Good luck Dave