Follow-up thread: High altitude starting, pinging problems

[rgnprof]

This is a follow-up to 2 previous threads - one on checking cam timing and one on engine knocking and injection pump timing. Anyway, we are in Colorado and car ran great until we hit about 5000-6000 ft and then it started pinging again on me - especially under any kind of load. We are staying right now at 8000+ and the car is a real bear to start in the morning - lots of cranking and LOTS of gray smoke. Once I get it running, it smokes about the way it did in OKC - very little - but still pings and knocks.

Since this is the NA '78 300D, there is no ALDA, and the FSM says that there is supposed to be some kind of built-in altitude adjustment - in the injection pump itself. I am also having trouble with the vacuum locks and the cruise (also vacuum controlled) does not operate as well holding the speed - both of which I know are altitude related. I know there is a vacuum connection on the injection pump - is that related to my problems as well???

I'm thinking of checking my pump timing again - any suggestions, or am I just stuck with these kinds of problems until I get back down?

Also, an interesting observation is that I am getting BETTER gas mileage when the car pings and knocks - I got 22-23 early in our trip and now I am getting above 25??? Maybe it was running too rich before...pump timing too far advanced (see my previous thread).


ryan