AMC 360 quit running

Driving down the highway one day and the engine backfired 3 or 4 times then quit running. Now when I try to start it, it just cranks but no fire. Then it backfires. Not sure where to start. Carb? Timing? Elsewhere? Was running fine up until that moment. HELP!!!!

Engine = AMC 360 V8 Late 70's/early 80's
Carb = Motorcraft
Jeep = 1975 CJ-5

 

Year and model of Jeep? Type of ignition - ie factory or aftermarket? Any modifications to the engine? If it's a CJ, who swapped in the 360?

In a no-start condition, you always look to see if you have fuel and spark. If it backfires, you likely have spark. Look down the carb throat with the engine off, choke plate open, and open the throttle. You should see fuel squirt in from the accelerator pump.

If you have fuel, and you have spark, then look elsewhere. Ignition switch? Neutral safety switch? Do you have power to the coil with the key on?

Welcome from Boston!

 

If you have the stock ignition, which is Prestolite, I would suspect the module.
If you have the Motorcraft system, I would suspect the pickup assembly in the distributor.
First, check to see if the timing is still proper. Do this by turning the motor over and checking the timing mark with the rotor position on #1.

 

Timing chain my have slipped a tooth or maybe even broken. Does the engine crank over faster than before which could indicate a non rotating camshaft.

 

The most common no-run situation on a '75 would be module failure, as tommycj mentions. Parts stores have a checker for these things, I think.

If the timing chain broke, there would be no spark at all, so it would not backfire. If it jumped time, it would have to be more than one or two teeth, since the engine will still run one tooth off IME. You should be able to see that if you line up the rotor with #1 and look at the timing marks.

 

I would start with having someone bump the starter while i am looking at the rotor of the distributor (cap off mind you). make sure you did not eat a distributor or drive gear. the pop before the no run situation makes me think of a mechanical timing problem.

 

same thing happened to me. i had a msd ignition and coil.
ran great, pulled out 2 rigs, then i went to leave and big backfire, wouldn't start, couple more back fires, ears were ringing...
turned out the coil went bad. we were about to head home when the local (to the trail) gas and service shop had a used vw coil they sold me for $40 (bastards, a new msd coil is the same price). i was back on the trail, and still going 3 years now.

...that reminds me, i need to put a real coil back in there! but i'll definately keep that guy for a spare!

check for spark, and good luck.