Which ECUs will work?

[schardein]

I found an 89 XJ at the pic-n-pull.  The Engine computer had a reman sticker on it, looked like it had been spray painted black, and I couldn't find a part number on it anywhere.  I passed. Good call?

[chris71]

i'd say that was a good call to pass on it . the ones i found i got from a couple local jeep clubs in town , i posted on there forums as to what i was looking for and within a day i got one for 30 bucks and another for free ,  :thumbsup:

[87 Comanche dude]

A mechanic replaced my ECU in 2012. He got one from a jy.  So for curiosity’s sake, I looked at it last week. 

It has a piece of tape on it that states “AUTO”.   I have a manual 5 speed and it works fine, which falls in line with Cruisers posts on the issue.  
 

The original sticker number on it is 56006078.  From researching comments on this forum dealing with ECU’s, I see that it works fine in my 87 base unit MJ with the 4.0 L.   Apparently it’s an upgrade and predecessor to the #’s 428/429’s.  
 

MY QUESTIONS ARE:

What model year did it come from?

 

Does it increase the HP in the 4.0 L?  If so to what HP?

 

Does it have the other improvements programmed into the 89 & 90 models with 428’s and 429’s in them?

 

I just want to know what ECU I have.  

 

Thanks for any help!!

 

 

Edited February 2, 2025 by 87 Comanche dude
Left out a word

[89 MJ]

20 minutes ago, 87 Comanche dude said:

MY QUESTIONS ARE:

What model year did it come from?

 

Does it increase the HP in the 4.0 L?  If so to what HP?

 

Does it have the other improvements programmed into the 89 & 90 models with 428’s and 429’s in them?

 

I just want to know what ECU I have.  

 

Thanks for any help!!

It should have bumped the horsepower from 173 to 177. I can’t say for sure what model year it come from, but I wouldn’t be surprised if 88 and 89 shared the same part number. 

[pizzaman09]

3 hours ago, 87 Comanche dude said:

A mechanic replaced my ECU in 2012. He got one from a jy.  So for curiosity’s sake, I looked at it last week. 

It has a piece of tape on it that states “AUTO”.   I have a manual 5 speed and it works fine, which falls in line with Cruisers posts on the issue.  
 

The original sticker number on it is 56006078.  From researching comments on this forum dealing with ECU’s, I see that it works fine in my 87 base unit MJ with the 4.0 L.   Apparently it’s an upgrade and predecessor to the #’s 428/429’s.  
 

MY QUESTIONS ARE:

What model year did it come from?

 

Does it increase the HP in the 4.0 L?  If so to what HP?

 

Does it have the other improvements programmed into the 89 & 90 models with 428’s and 429’s in them?

 

I just want to know what ECU I have.  

 

Thanks for any help!!

 

 

The 89 and 90 models are a bump up to 182 hp.  I'm not sure which ECU you have as I'm no expert in it but people tend to like the upgrade if you have an ECU from an 87 or 88.

[89 MJ]

57 minutes ago, pizzaman09 said:

The 89 and 90 models are a bump up to 182 hp.  I'm not sure which ECU you have as I'm no expert in it but people tend to like the upgrade if you have an ECU from an 87 or 88.

Oh yeah, it’s 182, not 177hp, I was confused earlier

[87 Comanche dude]

Thanks 89 MJ & Pizzaman09