Weber 38 has issues

[toy power]

Just built a 22r for the rig. .040" overbore, cam(214@/.050" intake), good valve job, header. Weber 38 will not work well. Stocker runs fine, no mechanical engine problems. With the Weber the truck will stumble very hard, almost a stall, and then take of when accellerating from an idle (when you upshift, for example). Accelerator pump is not adjustable, diaphram looks fine. I have attempted jetting the idle circuit and played with timing. Nothing seems to have an effect on the problem. You guys have any ideas?

[keyice]

sounds like the main jet is to big, 22rs don't really have enough pull in enough air volume to get the proper mixture with the stock webber jetting, that is why you need a high compression engine to have enough vacuum to pull over 400 cfm like a 38 webber is meant to do.

[Chevota]

i have a weber 38 on mine and it runs perfect out of the box and onto the truck. no major engine mods, hooker header thats it maybe a leak where the carb bolts on that would effect it , try cutting the air off of one cyl. and see if it runs any better??? i dont know but mine runs fine :redspotda

[toy power]

Where do you have your timing and jetting set Chevota? You running a pressure regulator?

[Chevota]

no preasure regulator on it . i have a cheap inline guage on it that usually says about 5.5 psi but the manual says to only run it at about 2.5 i think. not sure where the timing is because altitude change . the book says to put the mark on the 8 i beleive but i know its about 2 inches to the left. but it does run just about perfect. :orangesle

[Chevota]

i'll bet it isnt the carb though

[toy power]

Well, just how much were you willing to bet? After sending my $400 paper weight back to weber, they called and said there was a problem in the accelerator pump nozzle; what a shocker. Messed up accelerator pump-damn, I'm good. I just wish they would have listened the first time I called tech support. That bad carb cost me a lot of time and aggravation.