390 running problem
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Joined: Aug 2005
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390 running problem
I have a 390 that just got reconditioned heads, new timing chain & sprockets, will start and idle but when shifted into reverse or drive it stalls. Idles @ 1000rpm, Timing set at 12btc, Tends to back fire with fire coming from the carb. Holley 4 barrel with electric choke. Any ideas?
Thanks,
Sisu1a
Thanks,
Sisu1a
New User
Joined: Aug 2005
Posts: 10
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Originally Posted by sisu1a
I have a 390 that just got reconditioned heads, new timing chain & sprockets, will start and idle but when shifted into reverse or drive it stalls. Idles @ 1000rpm, Timing set at 12btc, Tends to back fire with fire coming from the carb. Holley 4 barrel with electric choke. Any ideas?
Thanks,
Sisu1a
Thanks,
Sisu1a
Sounds like the timing chain is off a notch. Did you set the crank and distributer at TDC before before disassembly? Check timing chain by setting at TDC and pull the timing cover to see if the marks are lined up on the sprockets. If it checks ok then look at the distributor and make sure its pointed on the #1 cylinder in the cap. Also chech the vacuum advance module inside dist. by appling suction to the line, you can buy a hand pump that will do the trick, and check to see if the retainer is still holding the module arm on the points.
Elder User
Joined: Oct 2004
Posts: 556
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From: Ridgeway, Virginia
First off isn't 1000 RPM idle speed way off? Shouldnt it be more like 6 or 7 hundred? It has been a long time since I looked it up. Maybe its 900 but 1000 just sounds like a lot. If someone were to set their timing on an engine that is idling too high the timing would be off considerably due to the action of the centrifugal advance. When timing an engine it is critical that idle speed be set first and vacuum advance disconnected.
With this engine I would try setting the timing correctly with the correct specs. Actually with todays gas a 390 has to kind of be tweaked from factory timing specs. Setting it properly will give a good starting reference point. I would try this before tearing into the timing cover to see if a mistake was made. The mistake was more likely during the replacement of the distributor.
With this engine I would try setting the timing correctly with the correct specs. Actually with todays gas a 390 has to kind of be tweaked from factory timing specs. Setting it properly will give a good starting reference point. I would try this before tearing into the timing cover to see if a mistake was made. The mistake was more likely during the replacement of the distributor.
Last edited by GregTruck; Aug 29, 2005 at 12:08 AM.
