1. Home
  2. Chevrolet Trucks
  3. 1975 C10 350 2bbl missing when cold

1975 C10 350 2bbl missing when cold

Missing on a couple of cylinders when engine is cold and choke is set. Lasts for about 1 minute or so, then starts firing all cylinders and resumes normal cold idle. Continues to run properly after it's warm. Problem started the morning after the timing correction, but I've verified that it is correct.

Background: NEW plugs gapped to .060, plug wires, HEI Ignition control module, HEI rotor, HEI coil, distributor housing, PCV valve, rebreather filter, air filter, fuel filters Adjusted timing to 6BTDC @ 600RPM in Park, readjusted idle to 600RPM in Drive

Other: Mechanic says .060 is too much gap for HEI, as resistance is too great. Book and truck stickers say .060 Valve cover cleaning and gasket replacemenet scheduled this weekend. Noticed there is significant oil "baked" on rickers, etc inside the cover. Will plan on running a can of detergent through before this. Could there be any relationship to the miss now that the timing and idle are correct?

Thanks, BT3

Reply to
BT3
Loading thread data ...

Problem

.060 for gap is perfect , and the timing is right, but if the chain is stretched, could be causing a problem, what was it before you moved the distrib? which plugs did you install? AC Delco should be R44TX. There is also an R44T, that should not be used. the X stands for wide gap HEI ignition. The T for tapered seat. there is also an R44TS that should not be used , the S indicates moderate extended reach 7/8 inch long and was used on the '76 and later Bosch plugs and GM HEI are a marriage made in hell

formatting link
gives a nice break downof AC plug codes. Is the choke pull off working correctly? Is the choke set correctly? the unloader measurement is 0.275 measured between horn top of choke butterfly, adjust by bending tang on fast idle cam

Whitelightning

Reply to
Whitelightning

The timing WAS 11 BTDC. As mentioned I moved it to 6. Perhaps I'll need to draw a happy medium.

Admittedly, I used the cheapest plugs since I knew I was only going to leave them in there until this weekend, then put in AC's. That might be my trouble. When I got them, they were gapped at .025. When I gapped them to .060, they just looked strange, pointing out almost.

The choke seems to be operating correctly. It WAS having some trouble when I got it, but I cleaned the exterior linkages, then lubricated them and everything actuates correctly. As far as specifics, don't know. My chiltons says "We'll just assume your carb is working OK, moving on ...". I would need the "Carb adjustments for Idiots" book, as it's always been my understanding that these things work on the principle of "faries and pixie dust".

The previous owner had just put a new timing chain on.

Thanks for the feedback, I've got some things to check.

BT3

Reply to
BT3

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.