1991 motor compared to 1995 motor

my 1991 motor died turns out its got a bad piston but i found a 95 motor for sale for $300. i was wondering do i need to swap wiring harness and ecu for it to run or can i use the same one out of my 91?

95 long block and 91 long block are mostly the same. just throw all your 91 stuff on the 95 block and you should be good to go.

sensors may or maynot be diffrent, go onto autozone.com and check part #s through the 2 yearsintake and exhaust should be the same and all accesories should be also

Naxja 1 jeep forum 0 it took me five minutes for a reply to this on here. i still have not got a reply on jeep forum and its been posted for about 15 minutes so mad props to this website.

thats because jeep forum sucks

I think 91 is a bit of an odd year for some sensors, among them the crank position sensor. I'd put any of the 91 stuff that isn't known to be identical onto the 95 engine if it was working right, but keep the 95 throttle body and other bits on hand, because at least some of those parts will interchange. I seem to recall reading that the early HO coils were more prone to failure than some, so you should at least make sure you don't lose the 95 coil as a spare. Actually I'd keep everything I could, but if you have limited room, at least make sure the expensive sensors, throttle body, ignition parts, etc. stick around.

Whatever the condition now, I suggest you take advantage of the engine being out, and replace the o-rings on the oil filter adapter, which tend to get leaky. They're cheap, but it's a bear to do in the limited engine compartment space.

One sensor you may have trouble with is the cam position sensor (or distributor pick-up coil); it changed mid 94, so it may not match your plug, or your computer... Best way to check is look at the plug ends, and look at the plate under the rotor under your distributor cap.

x2 on keeping 91 and 95 sensors on hand as they can always be spares for you if they work on both engines, and if they aren't the same, then they can be spares for some other XJ'er out on the trails! *L*

so what everyone is saying is to take the ecu and wiring harness from the other motor just in case?

You don't need to swap ECU or harness, just move the sensors from your 95 engine to the 91 engine and reconnect them to the original harness. You need to move the injectors and ignition parts too (distributor) since some of those also changed. Then everything will be back where it was, just like before, and only the iron will be different.

If you want to find out what parts are different, get on rockauto or autozone or wherever and open windows for 91 and 95 model years, and compare the part numbers

So I need to take the sensors that aren't the same off the 95 motor and use the 91 sensors on the 95 block

yes

Ok awesome thanks for your help I really appreciate it.

XJPhoenix said:

One sensor you may have trouble with is the cam position sensor (or distributor pick-up coil); it changed mid 94, so it may not match your plug, or your computer... Best way to check is look at the plug ends, and look at the plate under the rotor under your distributor cap.

x2 on keeping 91 and 95 sensors on hand as they can always be spares for you if they work on both engines, and if they aren't the same, then they can be spares for some other XJ'er out on the trails! *L*

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I know that the cam position sensor and distributor design changed, but wasn't sure about the connector. Perhaps someone with direct experience here can confirm, but if the two distributors are electronically equivalent then I might consider staying with the 95 one, simply because if the cam sensor ever does need to be replaced, it can be done in about a minute with the distributor in, rather than taking it out and apart as the old one requires.

I think the cam sensor plugs are the same, so you could use the same dizzy.