Hey, guys. I've just rebuilt a 20R for my 74 Longbed and I am having trouble adjusting the 32/36 Weber carb. The engine internals are all stock and I'm running a Petronix-upgraded distributor & coil plus a long header.

The engine hesitates/bogs down taking off from a stop, and tends to stall when I come to a stop sign-- but idles fine once I restart it or rev it up just before it stalls. Based on what I'm reading about Weber tuning-- and because I don't know the origin of the carb-- I suspect the carb is jetted for a different engine. (I bought the truck a year ago, and the not-original 20R with the Weber ran rough then, too.)

So-- just to make the truck road worthy, I'd like to install the stock 20R carb-- but I do not have all the emmissions garbage to go with it. My question: If I just plug all the vacuum ports on the stock carb will it run okay?

Thanks!

 

Let me modify my question-- "if I remove & plug all the vacuum ports EXCEPT for the lines to the brake booster and distributor?"

 

you should have no problem with the stock carb if you plug all the lines i actually did that on my celica before i rebuilt the motor seemed like it ran fine

 

do those carbs have vac advance,u may want to keep those

 

ive never had any luck plugging the lines on the stock carb, there are too many vacuum actuated diaphragms on it to function right.but then again, with a stock 74 carb there is much less vac lines then newer ones.


fixing the weber cant be too hard.



what is your mixture screw set at?

or how far away from the oem lean best idle setting are you?




with the stalling it sounds like the float level is too low and maybe your not getting enuff flow from the fuel pump (flow is not PSI). check the on car fuel filter and the in carb filter.


with the bogging from a start that sounds like your running a bit rich.

 

I was told by the guy who rebuilt my 18r-u carb recently that I needed to T off of one line to run to the dist for a vac, advance, and cap everything else. And he has been rebuilding carbs for the last 20 years. I havnt got it running yet due to spark issues but hopefully this week it will run and ill find out what those vac lines are running to that I need to T off of.