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Author Topic:   Motor Shuts down at 4500 rpm in 3rd gear
posted May 23, 2003 01:24 PM
My 400 is shutting down at 4500 rpm. The problem is intermitent, it happens about 30% of the time.

It seems to me to be an electrical problem, so I changed the distributor, cap/rotor, plug wires and coil and the trouble persists. The module is a 2 year old MSD HEI and I am going to swap it next.

Any other thoughts? This is a new Holley 750 double, but I don't see how a carb could produce this kind of trouble intermitently.


posted May 23, 2003 03:30 PM

race it
posted May 23, 2003 09:22 PM
Trace your wires and look for an electrical short. Make sure you don't have a wire grounding out on the chassis somewhere.

posted May 24, 2003 09:02 AM
Thanks guys, but this appears to be teminal.

Now the motor won't turn over when it hits a certain spot and one of me plugs is covered with aluminum with the electrode mashed in.

Somthin aint right.

posted May 25, 2003 10:29 AM
[do you run extended tip plugs and what kind of heads do you run you are probably running into a clearance problem with plug to piston and when you run it past 4500 it starts to hit the plugs and is causing your ignition problem run a non extended tip plug or shorter reach plug and see what happens

posted May 25, 2003 09:49 PM
aluminum on the plugs can only be piston. that's the only thing in the cyl. thats alum.

posted May 25, 2003 10:03 PM
remove cyl heads NOW!!!!!!!!! You got problems that must be addressed or you will be replacing a motor. If you've severely damaged a piston and it breaks you may then need a block, crank, cam, intake, heads, oil pan, etc.

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