Ok, if you read my egr solenoid saga, it is suggested to try a different ECU / ECM unit. I have a 1990 automatic XJ

So which ECU /ECM to get? Per the wonderful internet I have learnt that that not all Renix six cylinder XJ ECU /ECM s are the same. Supposedly the 89 and 90 models offer more power, the factory tweeted them verses the prior ones, AND the automatics are different than the manual tranny types.

I dont see any 1990 XJs in the wreckers (Pick n Pull) near me, but there are some on ebay, but they state they are for 88 thru 90 XJs and no mention if for automatic or manual tranny. Rock Auto has them, and list both an automatic and manual type, these are used units.

From what I understand from the internet is that the last three digits ending in 428 or 429 are for the 89 to 90 XJ, and that the 428 is specifically for the automatic, the 429 for the manual. I also read on the internet that either manual or automatic versions will work in my automatic XJ, but that the idle will be better with the automatic version ECU / ECM. Is this true?

So the correct and evidently best one for me is the 428 model, correct? this will be the later version with higher power capability, and is designed for automatics

Rock auto.....https://www.rockauto.com/en/catalog/jeep,1990,cherokee,4.0l+242cid+l6,1179996,electric al,engine+control+module+(ecm+computer),2896

Now the Rockauto units do have different part numbers, but they do list cross reference numbers, which include the 428 for the automatic, are these different numbers they claim cross reference, are they functionally identical to the 428?

Anything else I should know before I make a purchase?


Thanks!

 

according to fs1 website, there is only one for a 1990...

hope this helps..

https://www.fs1inc.com/1990-jeep-che...itional_tabbed

 

Any of them will work for testing purposes.

 

Agreed.

 

i got one ordered, exact same part number as mine. ebay

will let you all know how it works

thanks!