MY 93 F150 5.0 keeps jumping time! Help!!!
 

I have a 1993 F150 XLT with a 5.0 engine. I replaced the timing chain and gears recently. The chain and gears were replaced correctly. When I started the truck, it ran rough so I set the timing. I removed the SPOUT and set the timing to 10BTDC, replaced the SPOUT and all was well. At least, until the truck ran for about 30 minutes. When I put it in gear (either drive or reverse), it would go dead. I replaced spark plugs, wires, dist. cap, rotor and fuel filter. Then, I reset the timing (which was off badly). I started the truck and it ran fine for about 30 minutes. I could drive it and all was well. When it got warm, again, it would die when I put it in reverse or drive. I checked the timing and it was off again! Could my problem be a bad distributor? I have owned Fords for 40+ years and have never had this problem. Please help an old man figure this one out! :-huh

It could be a bad distributor gear , i would have a look at it....Lew

That's what I was thinking, just wanted a second opinion. You know, two heads and all that!

MY 93 F150 5.0 keeps jumping time! Help!!!
 

Not the problem, lew 52. Just checked the dist gear and it looks better than I thought one should look for 294k miles. No damaged or missing teeth. What now? Anyone have any thoughts?

??? i don't know , if the gear looked good then the cam should be ok , did this just start after you replaced the chain ..

MY 93 F150 5.0 keeps jumping time! Help!!!
 

I just recently bought the truck and the timing chain went out on my drive home. Fortunately, I was close enough to limp home. When I first test drove the truck, it was fine. Now, I can't get it to stay in time! It's driving me buggy! Every other timing chain I have replaced (quite a few in over 40 years) everything was great afterward. This one is a puzzler.

The only thing i can think of now is the pin that holds the gear on or the dist , is the dist locked down good so it won't move , balancer could be slipping...

The pin is nice and tight in the hole, no looseness. The distributor was tight, as well. The balancer appeared to be fine when I had it off. The rubber was hardly visible and I had to use my fingernail to feel it. It felt pliable.

The pin can be tight in the hole but be partly sheared, you may need th drive it out to tell for sure

You could also try this Vacuum Engine Timing | MILEPOSTS Garage (Tech Tips) with a vacuum gauge, I do this and it works out better for me, with these tired motors.

bashby-- The pin seems secure. When I removed the Dist., I tried moving the rotor while holding the gear. No movement. Pardon my ignorance, but wouldn't the gear or rotor have some play if the pin was sheared?

Slip Ford Man-- That link provides details for a carburated type fuel system. This is EFI. Would there be any differences in the procedures?

If the pin is partially sheared, you wont have any play in the rotor, the gear will move a few degrees at a time until it completely shears. I cant remember if the pin is solid or hollow on the dist gear, if its hollow (dont think it is) you could probe throgh the hole to check, but if solid you cant tell. If its partially sheared its gonna be a bi*** to get out.

Tomorrow, I have plans to make some home made pear preserves. So, either tomorrow afternoon, or Sunday, I'm going to check this out.
What I'll do is, set the balancer at TDC, remove dist and check roll pin (it is hollow, but has a tiny opening, perhaps 1/64"), replace dist to the point that the rotor points to #1 plug wire, crank and set timing (again). If it jumps again, I'll be back looking for more answers, or guesses, or any hope, really.
I'll keep you updated. Thanks!

It is now Sunday. This is what I have done. I removed the distributor, removed the roll pin holding on the gear. It was fine, reinstalled new pin. Set to TDC and re-installed distributor. Replaced dist cap, checked wires for tightness and firing order. Started engine and let it warm up, removed SPOUT connector, set timing. Same old problem. After a short test drive up and down the street, it wouldn't idle in drive or reverse. Checked timing. It was off again.
Could the cam have bad teeth or would that show up in some damage to the distributor gear? There were no metal shavings on the gear, although they may have been cleared away by oil.
I'm at my wits end. Please, if anyone has any thoughts, I could use some help!

I guess this is a stupid question, but are you 100% sure the distributor hold down is working as it should?

Just a thought..... Hope you find it..