Reply to "Multiple engine problems, help needed"

noquarterMember

Thanks for ideas

Today I got a little further. I took the Holley 600 vacuum from my Pantera and put it on the Longchamp. Then it ran fine! So it's a carb issue.

While it was running fine I took your advice and tried setting the ignition timing by ear instead of timing light. That improved the vacuum from 10 InHg to 16, almost normal. (The PVC system has been disabled by previous owner).
After that run I looked at the plugs, they were more even than before.

So the conclusion must be the Longchamp Holley is excessively rich on one side. I took it apart (again), also the bottom part, blew compressed air everywhere, and changed the power valve even though the old seemed OK. I then put it on the Longchamp, but still the same problem, plugs 2, 3, 5 and 8 way too rich.

How can the Holley be over rich on one side? I've also tried looking down into it while running, the fuel from the venturis look similar on both sides. Could it have a leak? Where? Any suggestions?

7/10/087:18 AM

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