Well. I have a 76 F-100 short <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-comffice:smarttags" /><st1:address w:st="on"><st1:Street w:st="on">Box</st1:Street> 4x4</st1:address> 360 4 speed manual transition.

It wont start. I did the timing gears / chain on it a couple of weeks ago.

The truck ran great for about a week. Now the truck won’t start. Cranks over but will not fire. I have spark, I have fuel, I have air (I assume the air filter is off). I have compression. The timing is set at 12 degrees BTDC. I am guessing at this since I cant get it started I cranked it to where the rotor was pointing at the number 1 cylinder contact and read the reading on the vibration damper. If any one knows what the correct setting for this truck is I would greatly appreciate it. Manual says to check emissions sticker under the hood. Its long gone!

The carburetor was replaced the same time the timing chain was done. It has a new coil, new fuel pump, new ignition switch.

It cranks fine just wont fire. I’m at a loss.

 

Sounds to me like the ignition module/pickup coil in the dizzy. Did you replace those before, and if so, with what..rebuilt units? Those DuraSpark units are mis-named. NeverSpark would be better. They were crappy and unreliable in the 70's and are now worse. Go with a modern electronic ignition system.

 

I have not replaced anything in the distributor. But if it were the ignition module/pickup coil in the dizzy would I still have spark?

 

You may have spark, but how good is it? It may be intermittant. The other cause why it won't fire is the truck may have jumped time. Since I can barely change a lightbulb, someone else will be able to assist you better. I just know that those modules were a PITA from day one.

 

Check yer plugs and see if they are wet. Like Bill said. It may have spark, Just not enough to fire the wet plugs under compression. I have seen this meny times. Replacing the plugs may work for a week or two than the same problem again.
Also you said that with the rotor pointing at number one you had 12*BTDC. It should be at 0 TDC. And only advance when running. So yer timming is off I would think.

 

Are you setting (closing) the choke before you try to start it? Since you mention the air cleaner lid is off, is the choke plate closed?

 

I have pulled all the plugs out cleaned them up and regaped them. they are not wet. The choke is partway open. I have tried starting it with the choke in both open and closed position.

 

It ran for a week...then died...Jumped time or ignition module. He just replaced the timing gear(s). Dunno whether he changed one or both, and did he replace the chain, too??

 

It's more than likely your ignition module. i had the same problem on my 77. you will still get spark she just wont fire. you can take them to a parts store and they can check it for you.

 

I had replace both timing gears and the chain. if its the ignition module is that located in the distributor? or is it the box on the drivers side fender?

 

Ign Mod is on the fender. I am still concerned about yer timing as the gear set should be strait up. Rotor at #1 and Timing mark at Top Dead Center.

 

I will reset the timming to TDC tonight when I get home see if that will get it started. I have my fingers crossed.

 

After ya drop the dizzy back in at TDC and #1. Ya should only have to advance it 6 to 8*,s. I think 12* is way to much on a 76 360.

 

Ok so what is ment by drop the dizzy back in at TDC and # 1?

 

If ya got 12* BTDC with the rotor at number one. Than remove the dizzy and put it back in with the timing mark at TDC and the rotor at number one. Than set your timing with vacuum to dizzy pluged.