Hello everyone, I am new here so please pardon any of my improper “Forum Etiquette”. I come here today seeking help with an issue I have with my 1981 F150 with 300i6. I was going down the road the other day and the truck backfired and proceeded to come to a stop. After a quick check to make sure the engine wasn’t blown up, I narrowed my issue down to spark. First I pulled the plugs and noticed they had a lot of carbon buildup on them. Being that The motor has only 2500 miles on it since a light rebuild and these plugs appeared to have 100k miles worth of wear I thought that the lean fuel mixture on my Carter 1 barrel was to blame. Long story short I got new plugs and decided that with a new carb I was going to do a bit of an upgrade. I put on a Holley quick fuel 450 carb matched to an Offenhauser C series intake, and thew on some Eli manifold. Anyway (now to the issue), in all of this I discovered that my distributor gear sheared off of the distributor shaft, easy fix, I replaced the distributor. My problem is though, I now have no reference for timing to at least get it close to where it should be so I can adjust with a timing light. What can I do to set the timing to get my engine to run well enough so that I can set the timing properly with a light?

 

I also would like to add that I did get the motor to crank, however it’s running very out of time and doesn’t sound healthy so I don’t let it run long.

 

Pull the number one plug. Turn the balancer by hand until you hear air coming out(put a wad of tissue over the hole to see when it blows out). You'll know the you are on the compression stroke. Put a long screwdriver down the plug hole and turn the balancer until the screwdriver stops moving, if it starts going down, just turn it back a bit. Look at your timing marks, they should line up. Turn it back until you are 10* before. Stab the distributor. Set the rotor about 1/2" - 3/4" counter clockwise of the number 1 plug, should line up with it when you stab. That'll get you where you need to be.

 

If it's running, then it's close enough to put the light on it and bring it in exactly where you need to be. Make sure to disconnect the vacuum line to the distributor if you have one before you time it.

P.S. If it won't stay running, you can adjust the hold down bolt on the dist so you can just turn it with some force from your hand. Then while it's running, twist it slightly one direction and then the other till it runs good enough to put the light on it.

 

I had it running, however it sounds very bad. I know you’re supposed to bring them to operating temperature before timing it. I was concerned with running it for an extended period with the way it’s running. Is there any major damage I can cause in doing so? If not I’ll let it run and turn the distributor until it sounds healthier and then put a light on it after it’s warm. Thanks for the reply.

 

I attempted to do this once already, however I think there are many reasons I messed up. The main one being that this was the first time I ever replaced a distributor (learning as I go with this truck) and was more worried about getting the oil pump shaft and drive gear to line up. What exactly do you mean when you say “Stab the distributor”? Thanks.

 

I attempted to do this once already, however I think there are many reasons I messed up. The main one being that this was the first time I ever replaced a distributor (learning as I go with this truck) and was more worried about getting the oil pump shaft and drive gear to line up. What exactly do you mean when you say “Stab the distributor”? Thanks.

P.S. Sorry if this is posted twice. I originally quoted the wrong reply

 

I just meant install the distributor when I said stab it.

 

Gotcha. Thanks for the advice. I’ll try it out tomorrow and see if I can’t get my hands on a timing light.

 

You don't have to let it warm up to set the timing. A cold engine won't affect the timing reading if it's idling slow. If it's idling fast, then yes you do need to wait till it kicks down to a normal idle. And you will still want to set the bolt so you can just turn the dist by hand, but it stays put. Much easier to look at the light, then move the dist, and then look at the light again.

That it runs at all means you got the dist in correctly. It doesn't have to be very far off not to run at all.

 

Alright. So I guess I can't really hurt the engine by running it out of time just long enough to adjust, so I'll give the timing light a crack with how the distributor is now.

 

Maybe before you check the timing go back over the firing order just to make sure it is right.
Get 2 wires mixed up and it can run like crap and sound bad.
Dave ----

 

I would like to thank everyone for your suggestions. I now have the problem resolved. Turns out my rough running issue was an exhaust leak and the engine was running fine. When I didn't have a helper, all i heard from inside the cab was my exhaust leak and it sounded like a knock of some sort. When i started it with my dad standing In front of the truck, i turned it off and he was confused. We then switched positions and realized that the motor was running fine it was just my exhaust making the racket. Got everything all dialed in now. Appreciate the help fellas!

 

Good to hear it was not something to bad to fix.
Also thanks for letting us know what the cause was as it may help others.
Dave ----