So, I finally splurged and bought a tester

[Mark_88]

for the vacuum and fuel pressure (bonus...two in one). So the fuel pump is pushing 7+ PSI like it should be....almost bought another fuel pump without testing it...would have had a spare anyways...

Then I tested the vacuum on the intake...seems to be fine when I close the choke butterfly and stays around 20 where it should be...once I open the choke I can barely keep it running and the vacuum drops off to almost nothing...the information with the tester says that if this happens the carb needs adjustment...also that the timing is off...but the truck actually runs well with the choke closed...so I doubt it's the timing.

I've tried all the adjusting I can do with the carb in various combinations of lean/rich and idle positions...so I'm pretty sure the carb is poooched...or, as we say in French, PHuked.

If anyone has any other suggestions before I start searching around for another carb I'd appreciate it...

TIA

 

[Kenneth S]

Since your truck runs better with the choke on it seems that you have some blockage in the carb some where, so try this little trick, with one hand work the throttle lever to get the engine rpm as high as you dare and hold it there, then with your other hand completely smother the top of the carb untill the engine allmost dies out and try to keep it from dying if you can, if not that's ok you can just restart it, by smothering the complete top of the carb the high vacuum created by the smothering might or might not clear up any blockage in the carb. That little trick has worked for me quite a few times over the years.

 

[Mark_88]

It's worth a shot...I know there is an open space in front of the main opening where the butterfly is that I can try covering over...since that is where it gets most of the air intake when the butterfly is closed...

Thanks for the idea...see what happens...