CIS nagging issue resolved? Last issues solved.

[ahh911]

Two issues actually:

1. After 4 to 6 hours of car sitting after a drive, the car would need about 3 to 4 seconds to start.

Fiddling around with the wur, I noticed the return fitting (with the copper washer) wasn't as tight as it should be. So I unscrewed and found a small piece of shop rag (1mm) between the sealing copper washer and the wur body. I cleaned it up and torqued the fitting back down. Have not had this problem return this year and it starts smoothly. This issue has existed since the first day I bought the car with wur pressures in spec. I think somehow air was seeping in but somehow no fuel was seen around the fitting, I know, weird. Coincidence? Don't know.


2. I've had the rpm surge slightly at what I thought was 1000 rpm when hot. Bought an Innova digital advance/tach timing light. Turns out my dash tach is off by ~ 200 rpm, so I was really at 1200 and mechanical advance was kicking in. Once I set the rpms correctly it's rock solid. Had I determined the actual rpm several years ago I'd have saved time and gas figuring a self induced issue.

Anyhow, all that's left is a slight surging at 2k rpm in 2nd, but I think it's the steep mech advance curve that my distributor has (mapped it out with my new toy). It comes up pretty steep at 2k and peaks then drops off a little. Would need a real distributor tester as my margin of error sighting the timing light is probably +/- 1 degree. A far as total advance at 6k rpm, I only feel safe at around 26 degrees. Tried 87 octane for the first time this year and at 29 degrees I thought I heard a little rattle at around 3k rpm full load, with 91 octane no noise. I think whoever re-mapped my distributor (prior to me) did an okay job, but the advance is a little strong in that 3k rpm area, essentially right at the high spec limit. So I a backed off to 26 degress and with the 91 gas I normally buy there should be plenty of margin. Car just whistles along with the orig muffler and timing backed off, really nice given today's need for every car and truck to blast out the pipes.

Phil

[PeteKz]

Phil, thanks for the update. I suspect that a lot of CIS minor running problems people ask about here are related to ignition advance not being correct, or irregular due to the dizzy sticking internally, or vacuum advance not working properly, or some such.

[ahh911]

Hi Pete,

3.5 to 6 hours after shutdown, the car would take around 4 seconds to start, it would happen nearly every time. The characteristic would be an instant catch for 1/2 second, then finally start 4 seconds later. The wur outlet fitting had a 1x2.5x1mm bit of shop rag between the copper sealing ring of the wur return line and the screw in fitting. Maybe it had nothing to do with anything.


As for ignition, all is true except I'm not nearly 100% sure that the notchy distributor advance at 2k rpm is the sole cause of the slight surging while in 2nd gear, to a less degree 3rd etc..

Phil