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chicklin · 12-01-2009, 11:32 PM

Made a little progress tonight. I set my timing using the vacuum guage rather than the specs under the hood (8 btdc). I advanced it to max vacuum and then backed it off about 1.5 inches from there, just to be on the safe side (I think the recommendation is 1 inch from max vacuum). It ended up around 14 btdc.

The popping is not completely gone but it definitely seems fainter and the acceleration and throttle response is WAY better. It actually feels like a truck now, not a schoolbus.

Now, I don't know if this is doing anything for the mileage, but it sure feels like an improvement. I'm going to drive it for a day or so and maybe advance it a little more again and see if it improves any more.

Does this sound at all consistent with the symptoms I was seeing? Is advancing the timing likely to improve the gas mileage?

12-01-2009, 11:32 PM	#10
chicklin Registered User Join Date: Jun 2008 Location: Kansas City, MO Posts: 108	Re: Exhaust popping Made a little progress tonight. I set my timing using the vacuum guage rather than the specs under the hood (8 btdc). I advanced it to max vacuum and then backed it off about 1.5 inches from there, just to be on the safe side (I think the recommendation is 1 inch from max vacuum). It ended up around 14 btdc. The popping is not completely gone but it definitely seems fainter and the acceleration and throttle response is WAY better. It actually feels like a truck now, not a schoolbus. Now, I don't know if this is doing anything for the mileage, but it sure feels like an improvement. I'm going to drive it for a day or so and maybe advance it a little more again and see if it improves any more. Does this sound at all consistent with the symptoms I was seeing? Is advancing the timing likely to improve the gas mileage? __________________ 1954 Chevy 3600 - 235, 4-spd 1986 Chevy Suburban - 350, 700R4 Last edited by chicklin; 12-01-2009 at 11:33 PM.