View Full Version : Overheated - now hard start, runs rough, dies

06-26-2009, 01:02 PM
Well I guess I get to join the dummy club. My 1984 351 PCM (no elec ignition) got overheated the other day. When I realized it I idled back to the dock. I found a leak in the hose to the water pump (hence no water leaking when I checked).

The motor didn't seize, it ran fine idling back to the dock. When I got home and it cooled down, I started it briefly, seemed ok. The next day I changed all my hoses, new impeller (old one was destroyed). Now the motor is very difficult to start. Cranks like crazy, acts like it wants to start but can't "catch". Then when it does start, it runs very rough for a minute or two and then dies (like it's not getting enough gas).

One oddity - took off the distributor cap, cleaned up points and rotor, put cap back on and it wouldn't even TRY to start. Took the cap off, confirmed that I had put the rotor back on (I had), put the cap back on and it immediately changed back to the earlier symptoms of (hard starting, stalling). Seems to indicate that the distributor is somehow involved?

Sorry for such a long post. Thanks in advance for help.


06-26-2009, 01:33 PM
things to check,

Compression.............or at least pull the valve covers and see if the valves are still moving.........overheated engines often destroy valve guides and seals. or ocassionally locks up a hydraulic lifter.

I assume you have checked for fuel pressure..and that the carb is getting fuel into the intake (some either helps diagnose this).

id ditch the points rotor and cap and put the electronic ignition on it.......its cheap and takes that problem out of the loop.........did you melt any of the wires going to the coil or the electronic choke?

Thats my .02 anyway

Good Luck

06-26-2009, 03:47 PM
X2 on checking your wires. Could have melted one with the high heat.

06-26-2009, 03:57 PM
X3 on the wires, and check for water in the oil. may have blown head gasket