Build Thread Question

[Whitewullff]

Sorry can’t find question tab and I’m too frustrated beyond right now. I have a 76 CJ7 AMC 304 that absolutely will not start. There isn’t any more reasons for it not to start. I’ve researched every possible thing and have replaced it all and aligned everything and it just cranks but will not fire over. New points, been gauged correctly, new coil, ballast, solenoid, distributor, new fuel lines flushed tank clean gas, new pump and filter . It’s getting compression fuel and pressure getting spark from the coil to the plug. Set timing by hand put mark at about 15* degrees btdc . Rotor is point towards number one plug just a litte before on compression stroke . Brand new plugs, cap is in correct firing order. Carberator is a motorcraft 2150 and i rebuilt it just incase. Cleaned blew out all jets. On and on it’s been done. I just want to push this money pit off a cliff beci certainly can’t sell it nobody would buy a $30k dollar POs that won’t start

 

[TSB8C]

Only takes 3 things for a gas engine to start:
1) Fuel
2) Air
3) Spark

Obviously these three must be in the right ratios, and for spark, at the right time. Do you have spark actually at the plug(s)? Pull one (or use a spare), connect a clip lead to the tab on the plug and a known good ground. With the plug wire connected from the cap, crank and watch for spark in the plug gap itself.

Checking air is easy - with the air cleaner off and carb top open, check that the choke is not fully shut blocking off air flow, nor is it wide open on a cold start attempt. A small screwdriver can be used to wedge it slightly open based on air temp.

For fuel, drop a bit into the open carb top and then crank. Coughing, sputtering, backfire would indicate starting attempts where fuel is getting burned. You can also look into the open top of the carb and check for a "spit" of fuel when you move the throttle (accelerator pump pushing a shot).

You said you had compression - on all cylinders? I saw an engine once with holes blown through the tops of 4 pistons. So #1 and #6 cylinders had compression, but 2-5 had none.

 

[Jeep Soup]

My Nickel.95
1) Some ignition solenoids have to (I) Stud on them. If there is a Wire connected to it, this Bypasses the Resistor in the Coil Circuit and gives full 12 volts to start. And as soon as you "Let Off" off the starter, it puts the Ignition system down to 6 volts again.

2) Do you have a "Ballast Resistor" in the Ignition System?
It looks like a 3/8" square by 3" long white/gray ceramic thing with a wire connectors on each end. Usually attached to the firewall with a small metal bracket. (WARNING! This unit gets Hot In operation)
It allows 12 volts for Start, warms up and reduces the Voltage to about 6 volts to the coil. This is to save the points in the distributor.

SO .......
If either one of these systems are not letting 12 volts to start......
You are going to have a hard starting issue.

IF YOU HAVE the Ballast Resistor System, carry a Spare. These fail,
Not Saying Often, but they reoccurring do. A quick Emergency Field Fix, put a wire across the two connectors (jumper) and you can drive your vehicle home to replace it.

Hope this helps,
"Dat Old Guy with a First Gen CJ"