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Old 08-01-2009, 03:01 PM   #7
bwood
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Join Date: Jan 2003
Location: Denison, Texas
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Re: stumbling/misfiring at 2500-3000 rpms

Quote:
Originally Posted by faribran View Post
if we are guessing.....
i have seen a small block produce these kinda symtoms due to a worn out timing chain and gears...
Quote:
Originally Posted by Green Machine View Post
Could it be the torque convertor locking/unlocking? Try resting you foot on the brake enough to turn on the brake lights next time it happens.
These are what I was thinking. The torque convertor locking/unlocking can also be cause from a brake light switch that is failing (makes the brake light flicker) or a bad Coolant temp sensor (makes the ECM think that the truck may not be up to operating temp.

Quote:
Originally Posted by 60ratrod View Post
well i did notice when i put my timing light on the motor i saw the timing mark jump around when i was trying to see where my timing was sitting. could this be a timing jump issue?? i'm gonna try to get my ecu read this weekend.
Timing wll jump around if you have not unhookrd EST wire.
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Last edited by bwood; 08-01-2009 at 03:04 PM.
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