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4.0 info needed

StretchTJ

NAXJA Forum User
Location
Kansas
I have a buddy doing a 4.0 swap into an MJ that I picked up for him off here last year. The MJ came tore down with no motor(originally a 4cyl truck), but a complete 4.0 warness(unknown year) in a box in the cab. He has a good 4.0(unknown year) with a harness, but upon further inspection, he is not sure if the harness is the same year as he was told that it was the one that came with the motor, but differing wire cuts say otherwise.
So, two seemingly good harness, one good motor/tranny/trans, and one MJ.
What we need to know is how to determing what year the parts are, ie the motor and the wiring harnesses. Are there numbers that we should be able to locate on the block(if so, where?) and the harnesses?
They found two different numbers on the intake manifold. They are: AY11596 and 33007067.

We also have a complete 97 xj that is being used for parts and a template to put this thing back together, but the motor appears to possibly have jumped cogs on the timing chain so we are not using that motor.

Thanks in advance.
 
The engine can be fairly readily identified by the cylinder head casting number, assuming that it's the original head/block pairing. The block casting numbers work on wider margins.

Cylinder head casting numbers are:
#2686 1987-1990
#7120 1991-1995
#0630 1996-2000
#0331 1999-2007

The only "grey area" would be for 1999/2000 - in 1999, the #0331 head was installed on the TJ and WJ, while the XJ didn't get the #0331 head until the 2000 model year. Other divisions are clean.

The wiring harness will be a bit more difficult. The 1987-1990 wiring can be readily identified by the presence of a plug for the knock sensor (should be on the same subharness as the HEGO plug and the CTS plug.) 1996-up can usually be spotted by having multiple HEGO plugs, but I'm not sure where they would be found. 1991-up wiring harnesses also use different connector shells for the Cranshaft Position Sensor - 1987-1990 used a three-pole Weatherpack connector (using only two cavities,) while I believe the 1991-up used a three-pole Deustch connector (again, using only two wires.)

I can't give you more than that at the moment, but you may find a clue that will help - or someone else may chime in with other critical data...
 
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