I have recently started having a problem with my truck. I put a 91 3.9 fuel injection into a 87. I switched all of the wiring as well as the gas tank and all the accesories. The only thing that would not work with the wiring was the 4x4 indicater, which I rewired and now works, and the transmission. The only wires that I put on the transmission were the three for the reverse lights, etc. There was another wire to the back of the transmission that I have unhooked and have not wired yet. The original transmission was a 4 speed w/OD lockout. The tranny that is now in it, is a 3spd from the 87. Now my truck will start up and run good for about an hour but will suddenly die while driving and not start for a couple hours. But the next day it will fire right back up. Does anyone know what the problem could be. I don't know if the fuel is regulated at all by any transmission wires, etc. Any help would be appreciated. Thanks.

Dave

 

This happened to me in my 92. When it wont start up again, put a fuel guage on it and make sure its getting enough. Th ebrushes in my pump were burning up but it would still run from time to time.

 

Could also be a bad pickup asm in the distributor or a bad coil.

 

My problem seems to be in the wiring. My injectors are pumping full blast when the key is in the on position. This instantly floods the engine and it won't start. The stalling before was caused by my plugs filling with the overdose of fuel. Usually the injectors stop when I turn the key off but I have had them continuously squirt with the key off and out of ignition. I'm going to replace my injectors and pressure regulator to see if that helps the situation. I'll have to check the pressure b/c something is not stopping the fuel flow like it should.

 

Double check the continuity of crucial wiring. Also double check connections, wiring itself, though small, can cause huge problems, just an idea, hope it helps.