I have a 70 Ford F-100, I got it about two years ago from a sketchy type of guy. I knew it was a project but I've been scratching my brain on this one. The engine I have is a 390, I'm sure on that. But the door says it was a 360, I pulled the pan off and saw the oil pump goes from front to rear, did some research, I have 4x4 and from what I saw, they only produced 4x4 with 360 not 390. Anyways, the problem I'm having is, with my engine I knew there was a timing issue, so I re timed it, got it going and it seemed fine for a couple days, then it went to crap again. I replaced the hold down clamp because I was told after a while those tend to go to crap. So once again I timed it and put the new hold down on it, it ran GREAT for a while. I own some property out of town and I said I would help a friend get out of a hole he dug in his 4x4 out there. So I get there and help him out have it run idle for maybe 2 hours. I head home and I loose total power, seemed like at the time that it was starved of fuel. So I tapped the gas a few times and it made a huge "THUMP" sound like a really bad gear change and regained power. I was just driving like ok limp home and check it in the morning. Well I get around the next corner and the same thing happens, but this time it back fired really loudly. It regained power and was limping really badly down the road, all of a sudden I loose power again. This time she dies and rolls off the road into a small ditch. I let her sit for about 5 minutes called to get some help and they said try to restart it one more time. So I did, and it made the most awful grinding sound coming from the starter and wouldn't turn over. I will check the starter tomorrow to see if it fell out of something, but I still need help wondering why this happened I've been thinking on it for a long time and the only problem I ever had with the truck is it back fire when I killed the engine. Otherwise nothing. I'm stumped and decided to join here for some help cause everyone I live by is a die hard Chevy and are actually kinda crude to a ford in need... Anything helps.

 

theonefordfan Welcome to and the FE forum.

You say that you know it's a 390, how so?

One can't look at them and tell the difference in a 360 and 390. They use the same bore block, with a different rotating system.

I think you issues are minor, I am going to suggest that you find an older fellow that knows his way around older Fords. That is what I do with my 66 F100 FE. He & I have an understanding of the truck, if there is a little issue he may listen, say raise the hood grab a carb screw and adjust it, or this or that. Close the hood and say give that a try. I'll usually fold a $10 or 20.00 bill hand it to him and drive away. He likes doing things the rest of the guys at the shop only think they can.

Makes a difference, give it a try. Don't sweat the chevy guy, they are air heads anyways.


John

 

I would also be checking the timing chain. Timing shouldn't change like that. I've never had a hold down clamp fail. Nothing to them to fail.

 

Im positive its a 390 I measured the stroke with a dowl rod a buddy of mine had. I just need ideas, if I knew someone who knew these engines, I would have went there first. I just need a list of what to check, as the other guy said, I will check the timing chain maybe its off by a tooth.

 

If an engine starts running bad, dies, and then won't turn over, I wouldn't consider the problems to be "minor" - but then again, I haven't been around the block near as many times as some of the dinosaurs on here.

 

Don't disagree at all. My observation when it works and then don't work it's minor, when it stops cold and won't go again til something is replaced, not so much.

I thought that is what I read in the OP, hit & miss.


John

 

Welcome to FTE
I'd check out your timing chain , some of them had nylon coated gears , after awhile the nylon breaks off and you are left with a lot of slack in timing chain . so you could have jumped a tooth or two or three ..

 

TRADE WITH ME

 

Another thing to check. The distributor driven gear, it's attached to the shaft with a roll pin. Not too uncommon for the pin to shear allowing the gear to spin on the shaft.

 

Another vote for a new timing set.

I have had a few different engines jump time. I try to take off, it hesitates. I floor the gas, it jumps and runs like a raped-ape. Shut the engine down, the backlash jumps the timing enough to keep it from starting.

The good news is the stock FE won't have any piston to valve interference when the timing jumps.

 

I also say ya are in need of a timing set. It's not hard to do
if your mechanically inclined. But it don't sound like you are.
Still with a good repair manual most anyone can do it with
the help of your FTE friends on here. There are them of us
that have had this happen and fixed it so many times that
we have forgot how to explain it to others. What you have
described is typical for an FE that is jumping timing. So go
get greasy Bud and welcome here.