Timing issue?
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Postmaster
Joined: Nov 2015
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From: O-O-O-Oreilly's
Timing issue?
Hi everybody,
My frankentruck is having symptoms of possibly too far advanced timing, but I am not sure. Cruising down the highway at 60-65, all is well, if I mat it, it sounds normal until the revs rise a little more under a load, then it sounds like a ping, but not as rapid as you would think a ping usually is. Also, it makes a little bit of a knock or ping when initially cranking at a hot start. Oil pressure is good, motor is healthy and pulls strong. I will check the timing tonight. Any ideas? Thanks in advance!
My frankentruck is having symptoms of possibly too far advanced timing, but I am not sure. Cruising down the highway at 60-65, all is well, if I mat it, it sounds normal until the revs rise a little more under a load, then it sounds like a ping, but not as rapid as you would think a ping usually is. Also, it makes a little bit of a knock or ping when initially cranking at a hot start. Oil pressure is good, motor is healthy and pulls strong. I will check the timing tonight. Any ideas? Thanks in advance!
Postmaster
Joined: Mar 2011
Posts: 2,698
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From: Taxachusetts
Yup, it sounds like the timing is a bit advanced. Check your harmonic (balancer) dampener for wear when you check your timing. Sometimes the rubber insulation gets hard and falls apart, leading to a false timing reading.
On a hot re-start, does the engine labor while cranking before starting? (= too much advance).
Do you have a stock cam or a "bigger" one?
You could adjust the vacuum advance by turning an allen wrench in the vac advance nipple on the distributor....if the diaphragm is still good (check it) - and you have that feature. Older distributors have it....DS I and II have it. Something to check, 'cause the diaphragms do wear out/crack leaving the carb to suck air instead of advancing the timing under load.
On a hot re-start, does the engine labor while cranking before starting? (= too much advance).
Do you have a stock cam or a "bigger" one?
You could adjust the vacuum advance by turning an allen wrench in the vac advance nipple on the distributor....if the diaphragm is still good (check it) - and you have that feature. Older distributors have it....DS I and II have it. Something to check, 'cause the diaphragms do wear out/crack leaving the carb to suck air instead of advancing the timing under load.
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Postmaster
Joined: Nov 2015
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From: O-O-O-Oreilly's
Checked for vac leaks and found none.
Looks as if the dizzy was out of adjustment. Set the timing back to 6° btdc and all is right in the world. Starts and runs much better!
Looks as if the dizzy was out of adjustment. Set the timing back to 6° btdc and all is right in the world. Starts and runs much better!
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