Ok, so the Jeep has been back at the shop that put the motor in for a while now. They swapped out the blown AMC 360 with a newly rebuilt AMC 304 bored over 30. All outside parts were still good and were swapped out. Oil pump was rebuilt inside out. I drove the Jeep home with no issues. I only live about 10 miles away from the shop. Went on a trip to town to pickup some goodies for the Jeep, about 8 miles. The problem I ran into was anytime I would stop while the Jeep was in drive, the engine would cut off. It will crank back up everytime until it reached about 190 degrees on the temp gauge, then it won't start again.
They towed it to the shop and have tried the following;
Changing out the ECM for a new one. (The Howell EFI uses an ECM from a 1989-90 model GMC truck with a 350)
Changing the Coil
All electrical systems check out. (Starter, Alternator, Battery)
The engine is getting spark, electric fuel pump is working, the EFI is sending fuel into the engine just fine. Plugs are brand new, gapped to .50 according to ignition system manufacturers instructions. The idle has been adjusted up and down with the same result.
The mechanic is at a loss for what is going on. He said the only thing he can think of at this point is that the engine isn't able to regulate its temp due to boring over, so he is going to try and put a higher temp thermostat in and see if that works.
Any suggestions? I just read about vapor lock, but since the fuel is getting to the EFI and engine strong until it cuts off, this doesn't seem to be the problem.
Luckily I am not getting charged for all of this since they installed the motor!