87 YJ 4.2 man trans immediate shutdown after starting


Shaker

New Member
Joined
May 12, 2021
Messages
1
Location
Md.
The wife and I recently had a nice 87 Yj given to us and we have an issue I cant narrow down. Engine starts and shuts right back down. I have ordered all new parts for it so it is up to date. Had a new carb installed prior to us taking it and all the vac lines seen good but also will be removed or replaced. Changed the fuel pump, gas filter, ( added a new glass filter prior to pump to visually monitor the sediment coming from the tank.) plugs wires coil and restabbed the dist. to get back in time. Has to be electrical. I have sprayed fuel in the carb upon start up with no effect and I am left scratching my head. Could someone help me narrow my search for possibilities. 168,000 miles so I also have ordered an HEI style distributor. I don't want to start doing further updates ie.. the water pump hoses belts etc until i know I can get this puppy runnin. The plugs were caked with carbon as well when removed. I am thinking the auto shutdown relay or ECM but don't know where to find the relays as of yet if there are any as it is a carb engine with mechanical pump. Any advice or criticism is welcome at this point in time.

Shaker
 

machoheadgames

Certified YJ Researcher
Supporting Member
Joined
May 19, 2020
Messages
416
Location
Dallas, TX
The wife and I recently had a nice 87 Yj given to us and we have an issue I cant narrow down. Engine starts and shuts right back down. I have ordered all new parts for it so it is up to date. Had a new carb installed prior to us taking it and all the vac lines seen good but also will be removed or replaced. Changed the fuel pump, gas filter, ( added a new glass filter prior to pump to visually monitor the sediment coming from the tank.) plugs wires coil and restabbed the dist. to get back in time. Has to be electrical. I have sprayed fuel in the carb upon start up with no effect and I am left scratching my head. Could someone help me narrow my search for possibilities. 168,000 miles so I also have ordered an HEI style distributor. I don't want to start doing further updates ie.. the water pump hoses belts etc until i know I can get this puppy runnin. The plugs were caked with carbon as well when removed. I am thinking the auto shutdown relay or ECM but don't know where to find the relays as of yet if there are any as it is a carb engine with mechanical pump. Any advice or criticism is welcome at this point in time.

Shaker
You don’t have a true ECM or auto shutdown relay on an 87.
They do have an ignition control module though so maybe replace that. Sorry, don’t know a ton about troubleshooting a 4.2L.