92civeg

ok so what im dealing with is a dieseling issue on a weber 34, i know this carb is known for running very rich ( or so i found out after i bought it) weber sent me 2 replacement idle jets after speaking to the guy on the hotline i replaced my 55 and 45 with a 40 and 35...and that didnt cure it,although it no longer seems quite as violent.
Anyway id like to maybe try some smaller run jets? does anyone think that could be causing an issue?
what everyone is running. for their jet setup?


here is a pic of my carb and the jets are numbered as follows

174 175
40 141 135 35


the 40 and 35 are the outside idle jets and the 174 175 are the jets up top....is this similar to anyone elses setup?

xxxtreme22r

dieseling issues are not caused by the carb running rich. If anything it's caused by the carb running lean and causing high combustion temps. Or improper ignition timing.

put an idle cut-off solenoid in the carb and be done with it.

Also what are you using to regulate the fuel pressure?

92civeg

there is no spot for an idle cut on the 34,ive had ignition timing set all over with no change. No regulator currently installed but it seems like 99% of people who run a weber on their 22r dont run a regulator.

crash121

How many turns out is your mixture screw? Generally 2 turns (+/- half a turn) is the sweet spot. If your truck runs best with less than 2 turns out, get leaner jets. If it runs best with more than 2 turns, get richer jets.

92civeg

truck runs flawless with it about 2 turns out.....runs so good that it doesnt want to stop running when i turn the key off!

xxxtreme22r

run a regulator, a weber style carb only requires 3-3.5 psi of fuel pressure, factory carb puts out 7-8psi.

Part of the problem is the fact with the extra fuel pressure it tends to want to open the needle valve too soon leading it to run rich. This is why most people complain they run rich, because they do not run a regulator like weber wants you to. Then they bad mouth the webers because they can't tune it right.

I'll try and see what I come up with as far as idle cut-offs for sync carbs.

92civeg

ill give the regulator a shot...ill post my findings

92civeg

went out and got the best regulator i could find a weber!

hooked up a pressure gauge prior to installing the weber regulator and my factory pump had the needle bouncing between 3.5 and 4 psi, which i though was weird beacuse the factory pump supposedly puts out 7psi or so ive read?

put the regulator on and cranked it down to 2.5 psi (do you you guys think its too low? still runs great) and it still wants to keep running and will cough out the intake before it turns off about 50% of the time. the other 50% of the time it shuts offf normally. what gives?

92civeg

it seems like its running rich only because after i run it ill come back 20 min later and its like its flooded and ill have to crank it several time before i can rev it up and clear it out. maybe heat soak? im running brand new ngk 7734.....what does anyone else run?