So we got the '78 out of the garage today and it was running good. We took it for a run and got everything warm, checked the timing, set the idle, set the carb and everything was looking good. Nothing was even leaking.

That was this afternoon. My son took it this evening and went to enjoy his new wheels. He put on probably 50 - 100 km and it died. I went to rescue him and it was back firing so I thought he didn't tighten the distributor down tight and it slipped.

I ran home and grabbed the timing light and hooked it up to check the timing but couldn't get it to work. My first thought was that there was nothing coming from the coil. Checked some wiring but couldn't find any problems. Just out of a hunch I pulled the distributor cap off and had him crank it over, bingo, the rotor never turned. It would move just a bit but would not turn.

I ended up towing him home. Once there I decided to pull the distributor and see if it still had a gear on the end, that's when I ran into my first problem, I couldn't get it to budge. I tried to pry it out with a screw driver and still couldn't get it to move. I had him bump the engine with the starter as I pulled and it finally started to move and came out.

The gear looks fine. I looked into the engine and had him crank it and I could see the cam turn. There is a bit of side to side movement in the distributor shaft but not real bad.

Any ideas on what might have gone wrong? I don't want to just put the distributor back in and hope it doesn't do it again.

 

Did the roll pin shear on the distributor gear?

Josh

 

No it looks tight and I can't spin it.

 

Sounds like it is time to look at the timing gears and chain. The moving of the cam maybe the pistons hitting the valves because of a broken timing chain or cam gear.

 

You have something really strange going on here. If the distributor didn’t turn then the roll pin is sheared, or the timing chain has snapped. You didn’t say if you saw the cam turning or not. If the cam is turning then it has to be the roll pin. Take a drift pin and tap out the roll pin. If it doesn’t tap out then it has sheared off and the gear is just tight on the shaft. You will have to use something to tap the gear off and remove the sheared ends of the roll pin from the gear and shaft and replace it.

 

The OP states after removing the distributor he had the engine bumoed over and the cam was turning.

So.... from that we could assume the timing chain is intact. But the rotor wasn't turning.

Roll pin has to be sheared, it just may be too tight to turn it by hand. I would put an extention down to the oil pump and make sure that turns, it might have locked-up.

Josh

 

Thanks guys. This is a new rebuild and everything involved is new other than the distributor.

I never thought to check the oil pump. I will check that today.

Any idea why the distributor would be hard to pull out?

 

well, if it was hard to pull out, i would either think your gears have been chewed up a little, or your oil pump is stuck. how did the teeth look on the distributor?

assuming you have the distributor out right now, take a long flat head screw driver and try to turn the oil pump. if you can't turn it, then there's your culprit.

 

Unless he's running a chebby motor he's gonna have a hard time turning the oil pump with a screw driver.

 

haha duh... my bad... been workin on too many chebby's lately.

 

Well I used a 5/16 socket in place of the screwdriver (lol) and the pump was stuck. I was able to get it to move with just a 1/4" ratchet so I don't think it was anything real big or hard.

I spun it over with a drill for 3 or 4 min and everything is moving fine and I have good oil pressure. I think I will replace the pin on the distributor and put it back together.

I may price out a HEI distributor for it, do they make a big difference in performance and mileage?

 

It’s kinda hard to beat the ford distributor. I wouldn’t waste my money on an aftermarket distributor. I would put a hardened roll pin in though.

 

X2 the Duraspark is hard to replace especially if it has genuine Motorcraft pick-up and module.

Josh

 

How does the underside of the rotor look? Is the molded block inside the hole of the rotor still intact (locks the rotor to the cutout atop the distributor shaft)? If so, you can vise up the dist gear (between 2 pcs of wood to protect the gear from vise jaws) and spin the rotor to check if pin is sheared.

Is the motor a 351m/400, 302, 429/460?

 

the pin was sheared. sheared when the oil pump stopped turning. It's a 460.