Engine ping.
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Engine ping.
Have a 85 f150. got a motor from a 89 efi for it, ripped off all emission and cpu control components. Has a holley 4160, and a clifford intake on it. switched everything over to dsII. runs ok big problem is around 3k rpm the pinging starts and its loud!! I have the vac advance to the full vac port on my manifold. if i put it to the timed port on the carb the engine runs really rough and has a hesitation.
my question is, is the pinging coming from having the vac advanced to full vac all the time and the intial timing set to 12 btdc. i have no idea what my total timing is dont have any timing tape but its gotta be high enough to make it ping. i havent driven the truck much and i wanna correct this before i do.
also truck smokes a bit to mostly when it starts to ping could they be related.
my question is, is the pinging coming from having the vac advanced to full vac all the time and the intial timing set to 12 btdc. i have no idea what my total timing is dont have any timing tape but its gotta be high enough to make it ping. i havent driven the truck much and i wanna correct this before i do.
also truck smokes a bit to mostly when it starts to ping could they be related.
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From: Virginia
Your timing is too advanced. I have had this problem, and found the original vacuum advance advances the timing too much. To make it work, you have to set the timing way down around 6 or 8 TDC. This makes the engine run like a dog. What I did was set the timing up to 12-14 degrees initial(so it would start ok when hot) and left the vacuum advance line off and plugged. That solved my problem, and I had plans to buy a adjustable vacuum advance so I could hook that back up, but never got around to it.
You can leave the vacuum advance unhooked, and the only thing it will cause is poor fuel mileage. You said the engine doesn't run correctly with it unhooked, but you need to re-tune and adjust everything after you unhook it. It really should be hooked to a timed vacuum port if you use it.
You can leave the vacuum advance unhooked, and the only thing it will cause is poor fuel mileage. You said the engine doesn't run correctly with it unhooked, but you need to re-tune and adjust everything after you unhook it. It really should be hooked to a timed vacuum port if you use it.
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well i definitly do not want poor fuel mileage, already got one truck that is a gas *****, dont need another one as bad. when i hook it up to timed spark port it runs rough, but that may be bc the carb needs adjusted and what i did is advance the timing to much to try and compensate for it??
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From: Virginia
When you hook it to manifold vacuum, the idle speed jumps way up. So then you close the throttle blades on the carb to slow it down, and then that changes your idle mixture. You have to re-adjust it to get everything back right. I am assuming this is a six cylinder, and if you have that larger carb on it, you may have to turn it up side down and adjust the rear butterfly adjustment to close the rear butterflies more, so less air will enter the engine. It takes a lot of fiddling sometimes when you change stuff around.
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