Engine will not start. really loud backfire!!! Timing maybe

[CarpeBronco72]

My 302 will not start back up. I was driving home from work, and I was giving it gas and it started to hesitate and jump around, this continued everytime I gave it some more gas. then there was a really loud backfire. the engine continued to run after that. But as soon as I got home it stalled out and will not start again. I reset the distributer and found top dead center. lined up the rotor button. but that didn't fix the problem? I get spark to all the plugs, and I changed the plugs also. I tried advancing and disadvancing the timing. but still will not start. before I resiet the distributer, only some over the cylinders were firing. PLEASE HELP!!!

 

[70_Steve]

If you can verify that the rotor is pointing to #1 spark plug wire with the engine on TDC on compression stroke, then no use in "resetting" the distributor. It's already correct. Almost sounds like the timing chain jumped a link or two.

How many miles on the engine?

 

[wildbill]

:- :- :- It sounds like you jumped timming and or the little shear pin in the dist shaft broke that holdes the gear not a bad job just some time good luck. : : : Bill 8) :

 

[74bronc]

I would start by taking the distributor cap off and watching the rotor as you crank the engine. The rotor should rotate. If that is good, i would bet that the timing chain jumped time.

 

[Jeepster]

I would think if the timing chain jumped something would be off (rotor,timing mark) with the actual #1 piston at the top of its compression stroke. When you pulled the plugs did you compare them to each other? If the dizzy's gear pin sheared, you would be able to spin the rotor by hand. Or turn the crank and see if the rotor turns. Back fire out the exhaust? If its not what the others say and you have a bad/dirty plug, look to that side rocker arm/ valve/pushrod.....Just a thought.

 

[Guest]

I had a similar problem a couple of years ago but the timing chain did not jump/skip however it was just very loose. It would not run until I set the timing @ 6 btdc and would run fairly smooth until I drove it then it would buck like a bronco and want to die. I ended up putting a new edelbrock double roller chain and steel gears on it. The chain was so loose, it just lifted off. I also added pertronics at that time to and it has been great every since.