My 1990 4x4 22re blew the head gasket and water pump seal. I went out and got the haynes manual and took it apart carefully labeling every hose and clip as i went. Unfortunately after putting everything back together i came across a couple of cables i don't remember seeing during the tear down. Maybe you guys can shed some light. here's a couple of pics. Shes running now just need a few hose clamps and i have to work out some trouble codes 52, 41, and 12. anyways thanks for your help.



this cable is from the main wire harness. its black and white with red horizontal stripes. theres no connector attached to the end.



mystery ground cable looks like from the firewall. not sure where this one goes.



here she is

 

The ground wire I believe is to the firewall from the head not sure can't really see it well enough to know where it's coming from but check your head on the left side and see if you have a grond on it if not that's the one that go's to you firewall from the head as for the other one i am not really sure again need better idea where it is located to be sure where it belongs but it may be the one that grounds below your manifold on the right side should be two that mount right under the intake runner check that out.

 

I believe the ground wire connects from the firewall to the lift hook bolt on the driver side rear of the head. The black and white wire I think goes to a vacuum switch, could you post a picture of the top of your valve cover , intake. so I can see what sensors you have.

 

52- Knock sensor
41-Tps
12- Rpm signal

 

down the load the Factory service manual with link in my sig

 

well after a couple of months i finally finished her up for now (been busy with work and family). She's all back together and running smoother than ever. For a while I kept trouble shooting a strange knocking only when accelerating. All my buddies kept saying it was the timing. After checking and rechecking then readjusting to make sure i had the timing nuts on I started thinking it might be a busted valve or something more expensive. But then I got to thinking maybe it was a busted exhaust gasket. I replaced the two smaller gaskets hanging off the header to the pipe going over to the intake side of the engine. Not sure what these are for. Sure enough I could see where the exhaust gasses had been escaping. I bolted it all back in and was amazed at how quiet she was. I still have not worked on clearing those codes out but at least shes running good. I will work on those later on down the road. Thanks for all the help fellas.