sensors sensors sensors....

I'm swapping in an 89 4.0 into my 87 XJ and keeping the 87 4.0 harness. I've got everything hooked up except for 2 sensors. The 89 is hooked to a five spd (which I put in also) but the 87 was an auto, I don't know if that makes any difference. One is on the throttle body of the 87 engine but there's no sensor in that spot on the 89, its a square, four-pronged plug. I'm going to run the engine without it and just see what happens. The other sensor I broke putting the engine in, it is on the lower driver's side of the block, I thought it was an oil pressure sending unit but it just threads into the block, there are no holes in the sensor itself. It has a plastic case (which I busted open) and what feels like silicone inside (its blue) I'd kinda like to know what to ask for at Autozone lol. thanks

The four-prong plug is for the transmission half of the throttle position sensor. If you got rid of the AT, you don't need it.

The other sensor that goes right into the block is the knock sensor, and you'll want to replace that since the RENIX ECU looks at it for timing issues. The parts has since been updated - you'll get a sensor with a stud - the stud goes into the hole and there's a nut that retains the sensor. Like I said, you'll want that sensor. (I'm assuming it's the one that's right on the oil pan rail - the one a little higher is a coolant temperature sensor, and you'll want that as well - it's a fuel metering signal.)

So, ask for a "Knock" sensor and you'll be fine. Plug off the four-prong job, and forget about it.

5-90

Thanks, I go to Advance and ask for a knock sensor, the girl tells me its 78 bucks and she has to order it. DOH! I was like, ummm I'll get back to ya. Autozone and Carquest told me that my Jeep didn't come w/ one lol. I was like ummm I'm holding the thing in my hand right now. Anyways I hit up the salvage yard, They let me hike up to the XJs and pull one off. Final bill: 2 bucks Annnnd I think I found a Dana 44 I'm gonna head back to check out, Why do those trips always end up costing more money than you mean.