[NTX5467]

I concur, timing chains don't "heal", they stay broke. In the times when those and later GM engines were in production, it seemed that when a timing chain "went", it was usually in the 80K mile range. A friend had a BEAUTIFUL black '73 Riv whose timing chain went one night. When trying to start the engine with a jumped timing chain, there's usually some backfiring and poor running. Advancing the distributor one plug wire notch might at least let it start, if there is no other internal damage.

Unless the points have slowly regapped themselves due to wear, I don't really see that as a culprit, but it might be a contributing factor to flaky driveability.

My '68 5467 had an issue where it would be running fine, even idling, and then the rpm would start dropping (with no drama) somewhat gradually. If I caught it, with a few extra pumps of the accel pedal, it'd come back and act fine.

It also did that while driving down the freeway. Pumping the accel didn't help those times, though, as it just stopped running as I aimed it toward the shoulder or off ramp. It was hard to get it to restart and stay running, but it eventually would. Sometimes, it would run at idle and sometimes it took fast idle to keep it running long enough to get it back into "D" and hopefully drive off (usually making sure the right rear wheel was on the dirt to lessen driveline shock when I put it into gear). When I got industrious (after getting it back to my storage shop), I put a new fuel pump on it and it started and ran better than it ever had.


There might be some issues with the carb's fuel circuits being clogged internally, but getting a good fuel supply would need to happen first.

Just some thoughts,
NTX5467

[low'n slow]

When you changed the filter, did you also change the filter in the carb? There is a little check valve inside the paper filter that can cause this same problem.

[sledhead]

ran into same problem with my 1956 found the problem is the new gas (Vapor locking) put NAPA elctric pump a long frame with switch under dash when car is ready to stall i turn it on works great. There is a articale in Old Car News August issue that has a different fix Put tee in fuel line after the pump plug center outlet drill .040 hole run return fuel back to fuel fill tube. Put fitting in fill tube. Chrysler and others have has the same problem. It's a guess!!!