Vehicle: 1979 F150, 351M, 2bbl, C6 trans.

Problem: Truck will not turn over.

Specifics: The truck was performing flawlessly. After returning from work one evening, I went back out to the beast to go get some dinner. When I tried to start the truck, it made typical low battery/bad connection sound. i.e. the starter relay would chatter when I tried to start the truck. I popped the hood and decided that the negative battery cable needed to be replaced (insulation peeling back and some corrosion). This did not help. I cleaned ALL battery and starter connections to bare metal. I replaced the starter relay. I replaced the starter. I ran a new ground cable from the starter housing to the battery. I replaced the starter to relay cable. I replced to positive battery cable. The net result, the same relay chatter. I have taken the starter back to the supply house and had it tested, worked fine. I hooked the starter directly to a jumpstart vehicle and the engine turned about 1/16 of a rotation before stopping. This I was able to repeat, after letting the starter rest for a minute I could reconnect and it would again turn only slightly.

Any help would be greatly appreciated. Firstly, I am beginning to lose hair over this one. Second, I had to borrow my friends chibby to get to work today. Not cool.

Thanks in advance.

-nate

 

The starter has to have a very tight connection to spin well. If you hook it up to a battery with jumper cables it may not work but still be fine. It happened to me. I'm not sure what else is going on. Or you sure the starter cable insn't touching the header or something? You could try turning the engine with a socket on the crankshaft bolt to see if it turns freely.

1977 Ford F-100
400m/c6/4:11/Gear Vender O.D.
Crane hydralic roller, forged, ported polished,Deamon,Edlebrock, yada, yada, yada
280,000 miles
Stock on the outside
modified/rebuilt everything

 

Sure sounds like you covered all the electrical. Maybe pulling the sparkplugs and trying it again may help diagnose the problem.
If it still doesn't turn over it could be some kind of internal mechanical binding problem. If it does turn over it could be a hydrostatic lock, like antifreeze in the cylinder.
Sure hope it isn't any of these things.

Sparky

 

Mr Weasel, welcome to the board!

I know this is a stupid answer, but nothing has been mentioned about the battery. Does it have 12.6V at rest?

 

I had the same problem with my '78 f-250 351m. I tried to start it start it and i would get the same chatter. i was about to lose my mind. then i decided to get a new battery and it turned right over. i know it sounds stupid but u never know.

 

Also one more thing, check you distributor. It may have come loose and turned itself out of time, i.e. hard start. I know it's a total long shot, but you never know.

RubberDuck

 

First of all, thanks for all the input. I never expected this much response this soon. Anyway, after work yesterday I tried turning the crank with a socket, bad news. Way too much resistance for a "properly operating" engine. I then removed the sparkplugs to ensure there was no coolant in the cylinders. The moment the last one came out of the block, the skies opened and the rains came. I was no longer able the work in the deluge. Oh well. I guess I'll try again this afternoon. I did check the coolant level in the radiator, and it was right where it should be. So that is the latest news. Again, any ideas would be greatly appreciated.

-nate