Weber 44 IDF Question Options

[orbit398]

Just looking to see if someone can help pin point an issue I am having – assume it’s a carb issue.

Here is what I have: 2.0 liter with flat top pistons (euro style), has ~160 psi on all cylinders, carb cam, bursch exhaust, dual Weber 44 IDF carb set up, idle jet = 55, main jet = 145, F11 emulsion tube, 200 air correction. Carbs are synced and pull the same at idle as well as about 1500. I live in Houston (sea level).

I have read and followed several write-ups on tuning the Weber carbs. Overall, the car runs great above about 2200 rpm. It idles excellent.

Issue: Still getting the occasional popping. More importantly, while under easy acceleration (throttle slightly opened/just limping along in traffic) ~around 2000/2200 rpm, the engine seems to be missing or it shutters. If I open the throttle just a bit more, it disappears and runs great. I cannot replicate this by just revving the motor up in neutral; does this only under a load??

What could be the issue here? I plan to recheck synchronization/insure carbs pulling equally, spray carb cleaner/starter fluid to check for air leaks, try to ensure butterflies are opening equally. Just puzzled at what it could be.

[IronHillRestorations]

Elliot's advice is sound.

If we assume that you are correctly jetted, popping through the carbs is a lean condition usually caused by clogged idle jets. That is as long as you don't have an ignition issue.

Make sure the linkage to the two carbs are dead nuts the same length. If the linkage is off just a little bit you can have problems.

What kind of ignition are you running?

If the jets are clean and you still get have that problem, I'd go up one size on the idle jets.

[orbit398]

Elliot's advice is sound.

If we assume that you are correctly jetted, popping through the carbs is a lean condition usually caused by clogged idle jets. That is as long as you don't have an ignition issue.

Make sure the linkage to the two carbs are dead nuts the same length. If the linkage is off just a little bit you can have problems.

What kind of ignition are you running?

If the jets are clean and you still get have that problem, I'd go up one size on the idle jets.

The PO added a distributor out of a 1.9 liter water cooled vanagon. Per the PO, it rev's higher and the advance curve was more aggressive (angle of advance is changing over a broader range of revolution). It also has the VW OME hall sensor or opto electronic sensor and electronics ignition module. The car ran fantastic when I test drove in the Austin hill country as we pushed it hard. I never putted along so I didn't know if the issue I have described was there or not.