Bob Barry
02-15-2003, 01:00 PM
I bought my Edelbrock Performer intake and carb back in December, prepped it all, and have been waiting for a weekend warm enough to install it on our GW. In the meantime, the recently-rebuilt stock 2150 carb has been a bear on startup, going into a "chug-chug" mode as soon as the choke pulloff opens up the choke plate a little.
Now I knew what the problem was; the pulloff wasn't pulling the plate open enough, or it was pulling it open too far, because I couldn't find my vacuum pump when I rebuilt it so I kind of eyeballed the adjustment, and since I was going to be replacing the carb ANY WEEK NOW, I never bothered to adjust it to run right.
Well, today my stubborn self realized that with it 15ºF out today, and tomorrow's weather forecast to be COLDER, I wasn't going to be doing the intake any time soon.
So, armed with my trusty Mity-Vac pump, a 1/4" nut-driver and a 7/64" drill to use as a clearance gauge, I set out to tune my truck the proper way.
Here is what I learned:
* In 15ºF weather, the squeeze-handle on a plastic Mity-Vac pump will snap in half like a wishbone.
* In a pinch, some needle-nose vise-grips can be clamped onto the remaining stub of a plastic handle and serve as a replacement
* In 15ºF weather, other parts on a plastic Mity-Vac pump, like the rod that connects the squeeze-handle to the plunger that creates vacuum, will also snap like a wishbone.
* When buying a Mity-Vac vacuum pump, buy the METAL one; it may not be cheaper, but it will eventually cost you less than the plastic version.
* A guy can tune out the "chug-chug" of a misadjusted choke by eyeballing the choke plate and turning the pulloff adjustment nut when the engine is first started, turning the nut until the "chug-chug" goes away.
Now I knew what the problem was; the pulloff wasn't pulling the plate open enough, or it was pulling it open too far, because I couldn't find my vacuum pump when I rebuilt it so I kind of eyeballed the adjustment, and since I was going to be replacing the carb ANY WEEK NOW, I never bothered to adjust it to run right.
Well, today my stubborn self realized that with it 15ºF out today, and tomorrow's weather forecast to be COLDER, I wasn't going to be doing the intake any time soon.
So, armed with my trusty Mity-Vac pump, a 1/4" nut-driver and a 7/64" drill to use as a clearance gauge, I set out to tune my truck the proper way.
Here is what I learned:
* In 15ºF weather, the squeeze-handle on a plastic Mity-Vac pump will snap in half like a wishbone.
* In a pinch, some needle-nose vise-grips can be clamped onto the remaining stub of a plastic handle and serve as a replacement
* In 15ºF weather, other parts on a plastic Mity-Vac pump, like the rod that connects the squeeze-handle to the plunger that creates vacuum, will also snap like a wishbone.
* When buying a Mity-Vac vacuum pump, buy the METAL one; it may not be cheaper, but it will eventually cost you less than the plastic version.
* A guy can tune out the "chug-chug" of a misadjusted choke by eyeballing the choke plate and turning the pulloff adjustment nut when the engine is first started, turning the nut until the "chug-chug" goes away.