Ed, I Know you are out there so, help me out with your opinion. I hear misses at the tail pipe when the coach is running idle. I know from the mechanics inventory that she found dwell variation when my tune up and diagnostics were done. So far, to smooth the the idle, I have been burning 100 octane and that helped a lot to smooth out the idle, but there is some missing that I can faintly detect. I have also given the coach BP 93 octane it seemed to run well each time but still with the miss in the tailpipe. So where do you think the primary cause is of the miss. Dwell variation can be caused by worn distributor shaft and/or a worn timing chain that has some miles on it, (81,500.00) also to some degree the exhaust can trap unburned fuel that accumulates in the header section of the pipe some time and reignite so I have come to understand can happen. Cheap fix scenario here now and I don't want to do alot to solve the problem. I'll do a rebuilt distributor, If I can isolate it or I'll do a timing chain and gears if I can determine the problem is there, I know some people change out there point to electronic. How can I fix it the most economical way to clean up the idle?
Dwell variation and idle
- Thread starter Michael Mykulak
- Start date
have to admit I'm not the expert on most mechanical issues. but I can usually get one to run. first try a set of the point eliminators. if what your hearing goes away them it was wear in the disruptor. or poor quality points- condenser. if not I would guess the timing chain is stretched. as long as it stays in time with in specks it's up to you if you live with it or try to make it better. but they do wear out if you drive them and they fall apart if you don't.
I've gotten the same with my '70. I switched to an electronic conversion, then back to a points distributor - there was always a slight miss at idle. Not obvious, but if you pay attention to it, every few seconds there's a miss. It's barely there, and certainly something I can live with... My guess is, it is in the carb. I'm probably going to do a carb rebuild in the spring, so we will see then.
Tom Hoczyk
PCS Past President
Attempt to help
In my experience, check: worn points, worn distributor breaker plate, worn distributor shaft bearings (bushings), stretched timing chain, worn timing chain sprockets. Carburetor: possibly an incorrectly set float, but I've also seen where the 2nd stage of the carburetor occasionally drips a drop of gasoline into the intake, unburned gas makes it to the exhaust, detonates there, makes the sound you hear. Tom
In my experience, check: worn points, worn distributor breaker plate, worn distributor shaft bearings (bushings), stretched timing chain, worn timing chain sprockets. Carburetor: possibly an incorrectly set float, but I've also seen where the 2nd stage of the carburetor occasionally drips a drop of gasoline into the intake, unburned gas makes it to the exhaust, detonates there, makes the sound you hear. Tom