My 1978 F100 XLT with 351M takes about 3 cranks to start after she's warm, and I just rebuilt the starter and put new cylinoid in it. Any suggestions. SHe starts right up when cold.

First off, what's your starting technique when cold and when hot? Might be a procedural issue and not allowing the carb enough fuel. What are other symptoms????? How long do you crank?


That said, my initial thought was the beginnings of an ingnition module going bad.

Do you pump the gas any when starting?

Check your timing bet it is off a little. Someone bumped up the timing this causes hard warm starts.

^^^Shoot...I bet that's it too. I was assuming your rig died and it was a hard restart. Depending on trans, you should be between 10-14* BTD.

Thanks for all the good advice, I will check the timing out. I am just learning how to work on trucks, so can you guys fill me in on how to check/fix my timing out!!! My transmission is stock and an automatic. Thanks

Sounds like timing to me also. Do you have a timing light or a friend you can borrow one from?

1978 Ranger F100 XLT said:

Thanks for all the good advice, I will check the timing out. I am just learning how to work on trucks, so can you guys fill me in on how to check/fix my timing out!!! My transmission is stock and an automatic. Thanks

Click to expand...

First you'll need a timing light/gun. Hook it up to your battery. Pull the vacuum line from the distributor and plug it. Start your vehicle. Then there will be a balancer with a timing pointer coming off the snout of the crank shaft. It'll be behind all the the other crankshaft pulleys. Point the timing light at that balancer, and the light should flash on 12-14* BTDC...if it's still a stock set up. Chances are, the marks will be worn on the balancer, so you'll probably have to go in there with a flashlight before this process, and mark the acceptable range with chalk.

Being the dumbest guy on FTF...

I just plain ol' don't understand the symptoms he's describing. :/
How sure are you that you do?

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1978, does the starter sound weak or labored like you've got
a weak battery or not-so-good connection? Asking since you
replaced the starter and starter-relay and I need to know why.

Alvin in AZ
ps- Nomenclature...
Two Ford starters for a 351w that don't have a solenoid...
http://www.panix.com/~alvinj/file12/starters351w.jpg
...short nosed one on the left is for manual transmissions.
Those are called "positive engagement" starters.

Does anyone use them besides Ford?

This is a starter with a solenoid...
http://www.panix.com/~alvinj/file12/starterBendix.jpg
...the solenoid pulls a lever that shoves the starter drive into
position before making the high current electrical contact to
run the starter's motor. It doesn't need a separate relay, it
does both jobs since the high current contact is inside the
solenoid. This type is supposed to use less current to do the
same thing as Ford's "positive engagement" type.

This is a starter relay (that's what Ford calls it BTW ...
http://www.panix.com/~alvinj/file12/starterRelay.jpg
...that one looks like it's for my '91.

When the circuit is opened on a solenoid the solenoid's rod is
driven back into place like it means it. It's kinda like when
the current is suddenly stopped through an ignition coil, a
reverse magnetic field is induced and so it "slams" the rod the
other direction.

Do you have headers on your truck and if so it could be heat soak problem.