Gene Posted February 16, 2016 Share Posted February 16, 2016 Hi everyone, I noticed this comment by Cruiser in another thread: "Get an 89 or 90 ECU regardless of trans. Instant 9 horsepower increase." I'd certainly like a few more horses in my 88 4.0 5 speed. I checked eBay, and they are listing Cherokee and even Wagoneer ECUs as being compatible with Comanches. I would have guessed the ECU would have to come from a Comanche. Comments from the guys who know? Thanks. Gene Link to comment Share on other sites More sharing options...
Gene Posted February 16, 2016 Author Share Posted February 16, 2016 Hi everyone, I just checked the Rock Auto website. It appears that they list interchangeability between Cherokee, Comanche, and Wagoneer. Interesting, though. A1 Cardone lists a separate ECU for 87-88, and a different number for 89-90. Standard Motor Parts lists the same ECU for 87 through 90. Gene Link to comment Share on other sites More sharing options...
gogmorgo Posted February 16, 2016 Share Posted February 16, 2016 MJ and XJ drivetrains (and just about everything ahead of the doors) are identical, so the ECU's are the same. The difference between the early and later Renix ECU's is down to programming, so they're plug and play. I'm curious as to which map the Standard one uses, but probably no one there could tell you. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 17, 2016 Share Posted February 17, 2016 Go to the boneyard and get one ending in 428 or 429. Link to comment Share on other sites More sharing options...
Gene Posted February 17, 2016 Author Share Posted February 17, 2016 Thanks Cruiser! Gene Link to comment Share on other sites More sharing options...
HOrnbrod Posted February 17, 2016 Share Posted February 17, 2016 Go to the boneyard and get one ending in 428 or 429. 53005429 and 53005428 ECUs are for the 89-90 manual and auto transmissions respectively. What exactly makes them different than the 87-88 ECUs to give an "instant 9 horsepower increase"? I'm guessing a timing advance? Link to comment Share on other sites More sharing options...
cruiser54 Posted February 17, 2016 Share Posted February 17, 2016 173 HP in 87, 177 HP in 88, 182 HP in 89 and 90. All due to timing and advance curve changes. Which reminds me. I need an 88 to 90 TCU. Link to comment Share on other sites More sharing options...
mjtjnj Posted March 1, 2016 Share Posted March 1, 2016 Cruiser, does this apply to the 2.5 and 4.0, or just the 4.0?Thanks Tom Link to comment Share on other sites More sharing options...
cruiser54 Posted March 1, 2016 Share Posted March 1, 2016 Cruiser, does this apply to the 2.5 and 4.0, or just the 4.0? Thanks Tom I'm not sure about the 2.5. Sorry. Link to comment Share on other sites More sharing options...
schardein Posted March 1, 2016 Share Posted March 1, 2016 173 HP in 87, 177 HP in 88, 182 HP in 89 and 90. All due to timing and advance curve changes. Which reminds me. I need an 88 to 90 TCU. Are we talking ECU or TCU here? Any advantage in different year TCUs? I don't own a Renix Jeep, but this is interesting to me as I like to go to the pick-n-pulls when I can. Sounds like 89-90 ECUs are worth pulling. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 2, 2016 Share Posted March 2, 2016 Grab 89 to 90 ECUs and 88 to 90 TCUs. I need a 1988 or later TCU........... Link to comment Share on other sites More sharing options...
schardein Posted March 3, 2016 Share Posted March 3, 2016 Grab 89 to 90 ECUs and 88 to 90 TCUs. I need a 1988 or later TCU........... OK thank you. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 3, 2016 Share Posted March 3, 2016 Does anyone have an 88 to 90 TCU laying around? I wanna ditch the OE one in my 87 MJ. Link to comment Share on other sites More sharing options...
chris71 Posted March 4, 2016 Share Posted March 4, 2016 so the 429 ecu would be for the manual trans ? i have an 87 5spd i'm interested in this gain , or just go grab both and try them ? Link to comment Share on other sites More sharing options...
Rockfrog Posted March 4, 2016 Share Posted March 4, 2016 I have an ecu from a 1990 auto currently running things in my 1988 5spd. Link to comment Share on other sites More sharing options...
chris71 Posted March 4, 2016 Share Posted March 4, 2016 ok cool so the auto part don't matter then , looks like i have jy run this weekend and pick a couple ecu up , thanks rockfrog :thumbsup: Link to comment Share on other sites More sharing options...
cruiser54 Posted March 5, 2016 Share Posted March 5, 2016 ok cool so the auto part don't matter then , looks like i have jy run this weekend and pick a couple ecu up , thanks rockfrog :thumbsup: Yup. The auto ones are more plentiful and work just great. Link to comment Share on other sites More sharing options...
chris71 Posted March 5, 2016 Share Posted March 5, 2016 ok so far i've been to 2 jy and have not found an ecu or any 89-90 models , anyways i have found a remaned one at oreilly's auto parts from a company called cardone? would these remaned be worth getting if i can't find a 89-90 in the jy ? i still have a couple jy to go to pickings are getting slim . Link to comment Share on other sites More sharing options...
cruiser54 Posted March 5, 2016 Share Posted March 5, 2016 ok so far i've been to 2 jy and have not found an ecu or any 89-90 models , anyways i have found a remaned one at oreilly's auto parts from a company called cardone? would these remaned be worth getting if i can't find a 89-90 in the jy ? i still have a couple jy to go to pickings are getting slim . Stay away from the Cardone crap. Link to comment Share on other sites More sharing options...
chris71 Posted March 5, 2016 Share Posted March 5, 2016 ok will do :thumbsup: search goes on. Link to comment Share on other sites More sharing options...
chris71 Posted March 7, 2016 Share Posted March 7, 2016 OK so I've ended up with two of the 428 ECUs , so today I am going to install one of them and see how it goes. Is there going to be anything I am going to need to reset like the TPS or anything at all. Thanks Link to comment Share on other sites More sharing options...
cruiser54 Posted March 7, 2016 Share Posted March 7, 2016 OK so I've ended up with two of the 428 ECUs , so today I am going to install one of them and see how it goes. Is there going to be anything I am going to need to reset like the TPS or anything at all. Thanks Plug and play. Let us know what you think. Ever had one out? If not, remember this: Remove the black bracket from the body, not the ECU from the black bracket. 10mm ratcheting wrench works best. Link to comment Share on other sites More sharing options...
chris71 Posted March 7, 2016 Share Posted March 7, 2016 OK cool will let you guys know Link to comment Share on other sites More sharing options...
chris71 Posted March 7, 2016 Share Posted March 7, 2016 Alright got the swap done today wasn't to bad to do , after a nice long test drive I cannot seem to stop smiling . the truck idles better smoother , the difference is noticeable from acceleration and the power through all the gears , it was even better in 5th , worthwhile upgrade to do . Link to comment Share on other sites More sharing options...
cruiser54 Posted March 7, 2016 Share Posted March 7, 2016 Alright got the swap done today wasn't to bad to do , after a nice long test drive I cannot seem to stop smiling . the truck idles better smoother , the difference is noticeable from acceleration and the power through all the gears , it was even better in 5th , worthwhile upgrade to do . Teehee..... Link to comment Share on other sites More sharing options...
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