Not melted or anything..looks brand new but it was also replaced & still the same issue!
Changing the CPS next!

 

If it won't even turn over, the CPS is not the problem.

 

You mean turn over as start?
When I say turn over, I mean it cranks as if it wants to start but won't actually start!

Anyway CPs was butt connected together and was causing a misfire issue below 2k and 100% throttle..as in going WOT from a stop it would misfire below 2k..now its all good and should fix that issue!

The reason the jeep isn't starting is the ECU is done! Blow or melt 2 doid...not sure why since no wires are chaffed or anything..everythings 100% ecu just popped! Pulled it to check the connectors & smelt that same burning smell, opened her up and yup 2 doids are burned.
So since everyone says the 90 Renix ECU has a better tune or something, I'll be replacing it with that tomorrow. 90 ECU out of an automatic will be going tomorrow. I hope its useable and I don't need the 5 speed version....

 

Turning over means the starter is turning the engine over, also known as cranking over. What I understand you have is a "crank-no start".

Glad you found it. Part number for 90 ECUs with auto trans end in 428. 89 may have the 428 ECU also.

 

Save the old one - if you don't need it for a core, I'd like to try to talk out out of it. I've got two other RENIX ECUs I need to do FA on, but it seems that the problem (if it happens) is blown injector drivers. And a fix has been devised for that - search it up on NAXJA, posted by Mr_W in Czechoslovakia, of all places!

 

Getting my 90 ecu for free so my old ecu is just gonna sit here..But injector driver isn't the problem...I wasn't getting spark?
Or maybe I misunderstood your post lol

 

I said it's the typical failure - but the ECU is too complex for that to be the only failure.

This is why I wanted to get the old one for FA - and to possibly devise a user repair, if possible. Especially if the failure is not of the injector drivers...

 

Nope injectors worked great. The ECU will be kept in the garage if you want it!
And what all happened with the ecu, is there a 1/2 burn that runs along a circuit or whatever the lines are on the green thing are...then 1 diode burned up & directly next to the diode theres a small burn on the green burn again but super tiny..so something shorted/burned up in there & was causing no spark..everything else worked 100& normal!

 

BTW Jon, do you only want failed ECUs?

 

Why for do you ask?

Kamaran - yes, I'll take it when you finally decide you don't need it. You have my address, ship it "best cost" and let me know when it's on the way.

Include a small card with the original application (model/engine/transmission/powertrain options) and your PayPal addy, so I can cover your nut for shipping.

If you don't still have my address, it's on my site.

 

Why for do you ask?

Because I may have access to a good useable one or two in the near future.

 

Jon if you want I have one from a 2000 & a 97/96..it was odd! Older style outside but had the new style dash & interior lol..a mut of the 2 years I guess unless someone did a hell of a swap on it!! It sure looked factory! and a 92..
These are all in working order and taking up space!

 

Throw 'em in a box, tape a card to them with the information given. Also, diagnosed failure or "Worked When Pulled" - I may have forgotten to mention that earlier.

If you can, I'd also appreciate about 6-8" of the wiring coming out of the thing - but don't scrap a vehicle to do it (save it for a vehicle that's being torn down.) It will make it easier for me to get in and figure out what's going on, and to make a breakout if I need one.

EDIT - As I said, "best rate." Sometimes, throwing things into a flat rate priority box is cheaper than shipping Parcel Post - so do please explore the options! Covering you for shipping is deductible for me (either as a "research expense" or materials for the Parts Exchange,) so I'm not worried about covering it - I just would prefer you to be out as little as possible while you're waiting for me...