1977 351M Carb Question, F150

That's not terribly far off if you jumped time...doubtful you hit a valve. But I thought it sounded like it jumped. So 2-3 hours of your time and a $30 chain...you'll be good to go.
 
My '78 351m jumped more than that & replaced chain & water pump (while it was off) in the driveway on a cold, windy day. Drove it another 15 years
 
See all that missing nylon...kissed a plug...head of the plug broke off...no serious damage. But did have an interesting little ball of spark plug bouncing around in the cylinder.

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Seeing how sharp that rig is, I'm Second guessing the help now...shoulda let you get pissed at it and sold it to me cheap.
 
UTfball68 said:
Seeing how sharp that rig is, I'm Second guessing the help now...shoulda let you get pissed at it and sold it to me cheap.
Click to expand...

Well, now might be your chance to get it!!! Currently sitting on the Side of the road waiting on a tow truck. Took her out for a little test driving, go for about 10 to 15 minutes, everything is great. Then bang! Dead truck again. WTF!
I'm mostly kidding about the selling part, but sure am pissed off right now!



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Have dome lights??? If not ground wiggled itself loose. After it cools, check if it fires...if it does...ignition module is toast. Beyond that, what are the symptoms?
 
What worries me is it did the exact same thing when the TC slipped........
Riding down the road, feeling good. The sun is shining, birds singing, wind blowing through my little bit of hair, pretty happy to have her running again; and then a loud "bang" backfire sort of sound and she dies. Lights work, she turns over and is getting gas but won't fire up. That is about as far as I got on the side of the road. Back in the garage now but was too aggravated to even want to look at it tonight. Just crossing my fingers I didn't screw up something with the chain somehow. I did recently install a cheapo Chinese ignition module so I'll try swapping that out and see if that is it; not feeling very hopeful though.
Thanks again!


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Looks like its jumped timing again! #1 cyl at TDC and distributor rotor not pointing at #1. So the question is what in the world did I screw up????
Uggghh!



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OK, what the heck has happened here...???!!??
Dots were together when I installed this damn thing and now they are 180 deg off. I can turn the crank by hand and hear a hissing/air noise from some where in the engine. Seems weird. Do I have a broken cam or crank or what?
 

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Rotate the crank one more full time...your dizzy is probably 180* out right now too. The hissing is probably the air in the cylinder escaping the plug holes.
 
UTfball68 said:
Rotate the crank one more full time...your dizzy is probably 180* out right now too. The hissing is probably the air in the cylinder escaping the plug holes.
Click to expand...
This. The crank spins twice for every rotation of the cam.

Also you'll hear compression blowing past the piston ring gaps into the crankcase as you turn it with a wrench, that's normal.

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OK Ben and Tim C, you guys are of course right. Got the dots lined back up by rotating crank as you said. With dots lined up, #1 cyl is at TDC as I think it should be.
Unfortunately Ben, I cannot take the dizzy pic as it is not installed. I pulled it out to look at it first before I opened up the front cover. I was thinking something might have happened to it so I pulled it to see. It is not broken. However I can say for sure that before I removed it, with #1 at TDC, the dizzy was not pointing at #1 but I don't think it was 180 out either.
So, something happened that was very much like the first time it seemed to have jumped timing. Maybe it wasn't the TC after all, either time. As noted before, it seemed to be running just fine after the last time I put it together. Drove it around for a while and then the "bang" and it dies. Am I barking up the wrong tree all together here? At least I have a nice new TC.
I really appreciate the suggestions!
 
It sounds like the distributor either moved from the hold down clamp being loose, or theres something else going on, LOL.

It shouldn't be enough to make it not run, but verify the rotor button can be turned and springs back, that'll verify the mechanical advance weights aren't hanging up. Make sure the vacuum advance rod is on the pin on the pickup plate and that it has the small e clip holding it down, make sure it moves and springs back, you can suck on the vacuum hose and it should move slightly, or at least try to pry on the plate with a screwdriver.

Stab the distributor back in and see if it fires. You now know the VALVE timing is good. If it fires, verify IGNITION timing with a light, and retry. If it doesn't fire or it dies again, you're going to have to diagnose whether it's spark or fuel related.

If it's backfiring when it dies, that could be timing, or fuel. Trying to accelerate if it's lean can cause a backfire.



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Well I'm going to be happy and pissed at the same time if it is as simple as a loose hold down bolt :)! Come to think of it, the dist did turn real easily when I pulled it out.
Wish I hadn't torn down the front end again...at least now I'm getting pretty good at it.
Tim - Do you know the answer about oiling of the TC when it's running?
Thanks again for the input. I'll try the suggestions above but not sure when I will be able to get it back together. I'll keep progress posted.
 
The timing chain is splash lubricated by the oil draining from the lifter valley and valve covers. Sometimes machine shops will drill a small pinhole in one of the oil galley plugs in the front behind the cam gear but that's usually only on performance engines that have a specific oiling issue to begin with.

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Looks like Tim ha you covered. Just out of curiosity...what's the gear at the bottom of the distributor look like? You didn't shear that roll pin, did you? And still stock cam? If all good, tighten that distributor clamp/bolt down (haha) and if it doesn't fire...I think we're back to fueling or ignition module. Typically, the ignition module won't cause back fires, but a bad one will cause a shut down scenario, and once it cools down, it'll fire again. Beyond that, it really sounds like it could be flooding, back fire, too much fuel kills it, and then I'd be curious if after it's given some time to drain back, it'll fire again. But you should have timing covered.
 
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