Fuel distributor shims

[Scott R]

I replaced my WUR a month or two ago, the old one was leaking. Ever since the idle has been too high. Its been professionally adjusted and the CO can be set for whichever amount I like, meaning I suppose that part is working. It's also had a professional control pressure test on the new WUR and that checks out as well. Same with vacuum leaks, there are none present. The AAR has been tested, the AAV and decel valves as well. sensor plate height is correct as well.

So I'm at a loss, the idle screw has to be all the way in to get it to 1100, which doesn't bother me, however at times it does not stay at 1100, it drops, or raises. Also warm starts are very difficult, I can shut the car off and leave it for an hour, come back and it starts, but the idle is very low for the first few miles.

I think at one point I may have added shims to the fuel distributor, but I can't remember. I'll go back in and remove them, however I can't find a procedure for determining how many shims should be in place. Is it based on warm control pressure?

[RarlyL8]

Fuel head shims change the system or control presure.
Go back and check your system, cold and warm presure. I would not rule out a vacuum leak either.

[Scott R]

Originally Posted by RarlyL8

Fuel head shims change the system or control presure.
Go back and check your system, cold and warm presure. I would not rule out a vacuum leak either.

Thats my thinking that control pressure is too high, do you remove shims to lower pressure?