cdmc1984

Hi every one I am new and like most new people I suspect I have come here looking for answers about my JEEP!
Ok!
So I have a 1993 Jeep Grand Cherokee Laredo in line 6, 4.0 engine, with a 42re Transmission 4x4. It went down for about 8 months now transmission went out and I have been tinkering with it since then. I rebuilt the transmission from front to back. We swapped out motors, because the old one froze up. We put in what I believe is a 1995 that came from a junk yard. We now have a crank, but no start condition and it keeps backfiring in both the exhaust and throttle body. We checked battery voltage and it's good. We replaced crank sensor, cam sensor, distributor cap, rotor button, spark plugs, and spark plug wires. I pulled cover and checked timing and timing looks good. I have 31 psi @ fuel rail and all fuel injectors check out at 14 ohms. I don't know what the voltage should be on fuel rail wiring harness, I tested and I am getting 7 volts on all the fuel injector connectors. From the harness side when I have key forward engine off. I don't think it's a mechanical problem, I think it's electrical possibly. If it is mechanical I would say it's the flywheel flex plate, I left the original 1995 on the motor, but the vehicle is a 1993 and I know the crank sensor picks up from there. Although I was told that the 1993 and 1995 flex plate were compatible. I checked all the vacuum lines, replaced and reconnected all vacuum lines that needed to be. I checked all my valves and they are opening and closing. It really feels like an electrical or a sensor issue that is causing it to flood. I swamped both the coolant sensors and the oil pressure sensor. I swamped out the intake and all the sensors there, we replaces the oxygen sensor about a year back.
I just want to rule something out that I am unsure about the 42re transmission has 5 or 6 different sensor inside and out (not including the crank sensor) because I just put in a new one yesterday but will any of the other transmission sensors effect if the engine starts or not? If so which once and how do I check them? What should be my supply voltage to my other sensors be? In the book I says there should be a ground wire from the fuel injectors to the intake manifold but I have gone over the entire wiring harness and the only ground I can find is the one on the passenger side of the motor below the coil that bolts to the block and I check it and relocated it on the block.

I dont know I stuck in a rut so any and all input is greatly appreciated!!!

cdmc1984

Are there any sensors on the 42re transmission that would cause a crank but no start condition?

cdmc1984

I got her running after re-disconnecting all the wiring cleaning all the connections with QC electrical connector cleaner blowing them all out with a air hose and then reconnecting everything waited over night then she started right up next morning. But now I have other issues. Like the ideal is a little high and the torque convert bolt are rubbing the aluminium shield plate between the motor and transmission?

Alexander James Leigh

I have a 1998 Laredo V6 4.0L And I can't get the turn signals to work. I have replaced the main combination switch, Replaced the flasher. Still doesn't work. I assume it's a bad connections somewhere didn't know if anyone has a idea on where the typical connection will be for the turn signals and hazards.

cdmc1984

I don't know. sounds like you might have bulb out. I did the same a few years back but the cluster switch fixed the issue. Have you checked the output at the bulb with a voltmeter to check for 12v? Is it front, back, left or right or just the entire thing?

97grand4.0

Your post is too long to decypher for me. Try simplifying .