I am OO of 88 4L Pioneer and purchased an ECM/ECU in 89 doing some shotgun troubleshooting.
Never used it since purchasing it since it didn't solve my problem at the time.
Would there be any difference in performance using the 89 vintage?
I would just try it but that could likely be very a subjective test. Just wondering if technically (software) is better/different.

Related question: I never liked how long it cranked before the engine fired up (3-4 seconds).
Any way to speed up the sequence like today's modern engine stop/restart at red light?

 

Probably notice a little more power.

The cranking time is never gonna change.

Go look at my site. www.cruiser54.com

 

Well, the 88 ECM has s different part number than the 89-90. I don't know what makes it different. Perhaps related to removing the C101 connector?

Anyway as Cruiser said, reducing the cranking time to that of a more modern vehicle ain't gonna happen. My '88 takes about the same time to start.

 

It was just a running improvement.

From my website:

 

Ya know, you Renix Jeep owners need to "cruise" through my website and check out all that is there.

 

X2. He has put together a great collection of tips that every RENIX owner should do. You'd be amazed at how just going through and cleaning up your ground point will help cure those weird problems.

 

Hi Cruiser54.
I have, actually, been to the website and watched the video above which led me to wonder.
My ECU seems to be pre-428, which led to my question.
Your site is a goldmine and I've successfully installed several upgrades you described.
Thanks for sharing your wealth of knowledge.

 

Hi lawsoncl.
I have no particular problems.
Just want to keep her going with some TLC now and then.