Here it is>78 400m f-100.
I drove the truck 50 miles to work as usual,no problems.I tried to start it to leave 8 hours later and nothing.All tune up items and ignition components are new.I checked for spark at coil,good,fuel is good.The rotor in the dizzy doesn't turn.Engine will backfire if I turn it over till it floods.I am thinking timing chain.I have to get a ride to it tomm and will be stuck there for 8 hours. I don't want to buy a chain tonight if anyone thinks it could be something else.Could it be the dizzy gear?Had oil pressure when engine was stopped.Also engine has been getting harder to start and missing a little also backfiring on deceleration every once in a while.I attributed it to a engine in need of rebuild.when I say hard to start I mean 1-2 seconds instead of the instant turn I have gotten used to.All help is much apprecited

 

It sort of sounds more like the rollpin in the distributor gear is broken..........since the rotor doesnt turn ..... and I cant say I have ever seen a timing chain completely break or stretch so bad the rotor wouldnt turn.
Fairly quick fix...that is if the distributor isnt corroded to the block as is known to happen very often on the 351M/400
Good luck.

 

110,00 thousand is my guess on the mileage.Also, a chain can't completely break to the point where a rotor won,t turn?

 

Are you saying the rotor bug doesn't turn when you crank the engine over? If so either the timing chain broke or if your lucky the roll pin in the distributor.

I guess it's also possible the dizzy gear sheared but pull it out and look at it closely.

 

That's right ,DUH ME !

I'll remove that piece of ignorance

 

this is what I found out today.I pulled the #1 plug and felt it while it was cranked,it is sucking and blowing strong so I am guessing the the cam is turning.I pulled the distrubutor and the gear is good .Also when i turn the shaft on it it works,turns the stator,etc..I put it back in and tried to crank. the rotor moves maybe 1/4" everytime I blip the starter but will not turn like it should.it just kind of engages i guess.the fuel pump is working so that also tells me the cam is turning.I am guessing not a timing chain.Could the oil pump have something to do with this? I am completly stumped and do not know what to do.please help

 

Timing chain is shot, the chain is jumping teeth!!

My 460 went out at 90K, all the nylon teeth where gone.

 

replace the timing chain, ford used a phenolic camshaft gear and if it has never been changed it is worn away to just about nothing. the distributor gear should start to move within a second of you turning the crank. turn the crank bolt with a 1/2 drive breaker bar back and forth (CW AND CCW) and watch the distributor gear, should move right away

having strong sucking and blowing AKA compression has nothing to do with the chain and gears, you would be checking for a bad ring that way.

the oil pump has nothing to do with the ditributor gear turning, the distributor gear is turned via the camshaft and in the bottom of the distributor is where the oil pump get's it's drive from. won't affect your timing

 

[QUOTE]Originally posted by peachhead25
I pulled the distrubutor and the gear is good .Also when i turn the shaft on it it works,turns the stator,etc..I put it back in and tried to crank. the rotor moves maybe 1/4" everytime I blip the starter but will not turn like it should. ------------------------------------------------------------------------------------ Did you make sure that the gear is physically attached to the shaft (via the roll pin)? hold the shaft and turn the gear and make sure they turn together.When you breake the pin in willdo this.The sudden jolt causes it to "jump" like it going to turn but it doesn't.

 

I did check the pin.Everything seems to be intact on the distributor. I thought if the chain is broken the cam will not turn causing the valves to not move thus having no compression.When my mitsubishi thru a belt If I tried to crank it it would turn real fast cause it had no compression.If the chain or one of the gears broke would the fuel pump still work? I thought it worked off of a cam lobe.

 

Peach go back and RE READ the posts!!! It takes 5 minutes to see if the chain is bad.
All my Fords had the bad timing gear, happens all the time.

Thank God my 302 HO has a true roller from the factory.

The answer to your problem is the chain.

 

No,the fuel pump shouldn't work if the chain is broke.You MAY get some compression on some cylinders though. I guess your next step would be to check compression all around huh?That should tell you something.

 

if the chain is completely broken the fuel pump will not work at all! if the cam gear is worn away, just the least bit will throw off the timing, the fuel pump will still work but that does not diagnos your problem

like pro3qtr said reread the post's and if you follow what has been said it will be very easy to figure out your problem

 

I still do not know what to look for now.This makes no sense to me.If the fuel pump is steadily pumping fuel.I diconnected the line and checked while someone turned it over.As far as I understand the fuel pump cannot work if the cam is not spinning.If the cam is spinning then the distributor should spin.I took it out and turned it by hand.I grabbed the gear and the stator and turned in opposite directions,the pin and gear are fine as far as I can tell.My boss seems to think that something happened to the cam itself like the gear on the cam ate away.I do not agree.I am going tomm to check it out again.Thanks for everyones help

 

Do you have an electric fuel pump in the system also?

The camshaft timing gear is probably shot. The OEM gear fails at around 100K. I replace it on any old Ford with 80K or more.

If the distributor is OK and it does not turn with the engine then you either have a bad timing set or a broken cam. Either way you will need to open the engine up and check. The timing set failure is a more common failure than the camshaft. If you replace the cam you will need a new timing set anyway.