cowboy450

If you mean the thermostat housing sending unit, no but they would probably have put the old housing on it. I'm thinking HO head after doing some research.

Ok, this bothered me enough that I just went and checked. My wire was hanging behind the valve cover so all is good. I don't think I will have a problem drilling the hole but it is still a mystery.

It hasn't been filled, still a rough casting like the rest of the head. This is an 88 so I'm sure it's not a late model head. As for drilling, grease on the bit and the start the motor to let water pressure shoot out should take care of that. My biggest worry is wiring if I don't have one. I hope it is hanging around somewhere.

Yep, back of the head, same place as my 89 XJ. There is a cast in boss there but it isn't drilled and tapped. Every one I have worked on has had a temp sender there. Got me puzzled. This motor is supposedly rebuilt, aftermarket head?

Ok, still haven't gotten to drive it, hopefully soon. New fuse box is in most of the way. I picked up a dash with gauges instead of lights. My head doesn't have a place for the new temp sender. There is just a undrilled smooth round spot there. No problem with that, I can drill and tap it but I have no wire. I thought Jeep used one harness, would the wire be tucked in the loom or something? If not how do I wire it? Thanks.

Ok, TPS is ok but was out of adjustment. Throttle body and IAC weren't too bad. I found one very small vacuam leak. EGR seems to be working as intended. I hope to drive it some tomorrow and see how it does. I was wrong about my fuse box, it does have damage on several connectors. Anyone have one laying around they want to sell? If not I hope to find one next weekend at the Knoxville Pull a Part. I'm thinking just clip the wires about a foot from the box to give myself plenty of wire to work with.

Ok, fuse box is fine just needed a little cleaning. The bulkhead connector was full of something that resembled tar. I cleaned it out (by the way contact cleaner won't touch this stuff) with carb cleaner, packed with dielectric grease and reassembled everything. It may be a few days before I can tackle the motor. I dug up my spare TPS and O2 sensor so I will let everyone know.

As I said I do have quite a bit of Renix experience. I pull the TB when I clean it so no problem with sensors. I have a spare TPS and do know how to adjust them. I think I will go get some different cleaner for the fuse box. I don't want to do anymore damage. Hopefully I have a spare O2 sensor. I'll do all that and see what happens. The truck has 225s on it and 5th gear really surprised me. It pulled really well. It crossed my mind that the rear end has been changed. I'll check and post what I find. Thanks everyone.

Howdy all. I'm a noob here from Lyman, SC. I just bought a 88 4.0, Pukego BA10 tranny, 2 wd. I'm not new to jeeps as I also have a 88 YJ, 89, XJ, and 95 ZJ. The MJ runs great but above maybe 60 MPH when you let off the gas and cruise it seems to miss. Touch the gas the tiniest bit and it smooths right out. I have some RENIX experience from my XJ so I have a few sensors, etc laying around. I think maybe starting by cleaning the throttle body and IAC, replace the TPS with a known good one. All vacuum lines look to be in place but I'm going to go a little more in depth with them. It feels like a lean condition but I know that can be misleading. I'm fairly sure it's not electrical because if you hit the gas it smooths completely out until you back off again. Another thing I noticed a few hours ago was that my idiot lights had gone out. I whacked the fuse box and the blinked back on. After further checking I found the dreaded clutch master cylinder leak. What is the best way to clean this up? Carb cleaner and compressed air and check all connections? Thanks.