Quick time line of the truck. (sorry for the long post)

I bought the truck with a few issues as a project truck, and I haven't been able to drive it since I parked it when I drove it home.

1979 F250 with a supposed stock 400 in it. 4spd and 4x4.

I replaced the clutch linkage as it was all rigged up, went to test drive and has had trouble ever since.

-I replaced the silver box ignition module.
-I rewired the coil and traced all wires pertaining to making it run. All good there.
-Finally got it running by turning the distributor all the way clockwise, made me and my mechanic friend think it jumped timing. Check the distributor gear and it was fine.

-Replaced the timing chain with a nice double-roller cloyes, advanced the cam 4 degrees. The old chain/gear had NOT slipped, but was very loose.

Now the fun part that I've been fighting the past few days is getting it timed correctly. When the distributor is adjusted to where the truck idles good and revs up nicely the thing is hard to start b/c the timing is too far one way. I spent yesterday adjusting the carb so it would hopefully run with it turned back counter-clockwise...could never get it to run worth a flip.

-Replaced the starter yesterday thinking it was just a weak starter, as it ran great. No difference.
-Today I finally got some white paint to mark the balancer so I could read it and time it. Initially it was something like 30+ degrees(past the marks), I had the vacuum advance blocked and everything. So I tweak it and am able to get it down to 9 degrees but the truck runs like absolute garbage. Spins over easy, but barely started and if it did would only idle and die when trying to rev it up. I tried numerous times to adjust the idle-air screws using a vacuum gauge and several different guides I found around the site(motorcraft 2150)

Finally said screw it and turned the distributor back the other way to where it idles/revs great, but is now hard to turnover again. It also wont idle below 1000rpm. that's where I'm at now, still haven't driven it b/c I seem to be stuck in neutral/reverse...gotta fix that too.

Any input would be greatly appreciated...i'm about to go crazy!!

 

ah wtf...I had it all arranged nicely!! It decided to strip all my line breaks

*edit*nevermind I fixed it, noscript on firefox made it weird*edit*

 

You don't block or plug the Vacuum advance.. you plug the vacuum hose that goes to that part.

Maybe you are on tooth off with the distributor ?

Have you set the timing marks then looked at where the rotor is pointing ?

Checked and verifed the firing order ?

 

I think I recently had the same issue as you but on a 302. Turned out, the outer ring on the 40 year old balancer had slipped. I originally thought the engine had skipped a tooth on the timing chain, so tore it all apart and replaced a 1 year old chain with a double roller, and when I put it all back together I still had the same issue. When I timed the engine, it ran poor, but when I cranked the distributor over in one direction it would smooth out. So you might be off a tooth if you have it cranked all the way over. Move it over and adjust it until it runs and starts smooth. Hope this helps.

 

First check and see if the #1 cylinder is at TDC with the rotor pointing at the #1 position(approx. 1 o'clock) on the distributor. If not, you will need to reset your distributor location. The firing order is 1-3-7-2-6-5-4-8 going counter clockwise.

 

Before I tore-down for the new timing chain I checked the #1 piston tdc and the rotor position and it was good. The motor purrs once it gets running. Also, when I just set the timing by ear and get it to where it runs good, it is hard as hell to turn over. So I back the timing off(ccw) slightly and slightly until it turns over good, but then it still runs like crap.

I'm starting to think It may just have the wrong balancer, or the ring on it slipped. When I had it off I didnt notice anything wrong about it, but it was the first one i've had off.

When setting the base-timing, I should leave the distributor uncapped and just plug the hose?

On a side-note...if I were to pull the distributor, how would I know where to put it when it goes back in? I initially marked it, and dropped it back into the same exact position. But lets say it was a new one, does it matter where its turned as long as piston 1 TDC and the #1 rotor are lined up?

 

It doesn't matter as long as the vacuum canister is facing forward.

 

ok, thats what I was thinking. Thank you.

Any input on the rest of the issues?

 

You really need to check if this is the correct balancer. I think the balancer for a 400 is 6.5" diameter.
Also, if you have access to a timing light with degree settings, you can compare what the balancer is showing compared to the timing light.
You're correct about the vacuum hose. (Pull from distributor and plug for base or initial timing check)

 

I'll double check the balancer, would a 351 balancer be a differenct size?

The timing light I have only has an on button and a clip for a spark plug wire(i've been putting it on #1) and ofc the power clips.

Do I leave the distributor uncapped? would that matter?

 

I would think the 351M balancer would be the same, but check with a parts house and see. Both should be 28oz. external balance.
Leave the distributor unplugged during base timing.

 

Its sounds to me like the weights in the distributor are stuck at full advance.

 

Wrong, You have to have the rotor pointing to the same place when fully seated

AND the vaccum advance should be pointed forward for ease of turning.

 

pretty sure thats what he meant. It doesnt matter where the whole thing is sitting at as long as #1 tdc and the rotor is on wire #1.

 

You're correct