ECU gone bad?

[MaciekPL87]

Hello,

This is my first post on ExplorerForum. I have a '93 XLT with 130k miles.

About a month ago the truck just stalls out of nowhere. Start it back up and it's fine. It did it probably once every two weeks. It's an Automatic.

Driving to a friends house on SuperBowl Sunday the tachometer started bouncing and the engine felt as if it was misfiring or bogging. CEL lit up. 10 seconds later truck ran fine, and CEL went off. As soon as I pulled in to park the truck could barely stay lit and the engine sounded as if it had a humongous cam in it. Ran very rough.

Three hours later I got in, started up perfectly and drove home perfectly with no CEL.

Monday going to work it started doing the same thing at the exact same spot on the road just cruising. The CEL stayed on and truck ran like crap all the way to work. Black exhaust meaning the engine is getting flooded with fuel.

Mechanic read the codes. 5 sensors had low circuit voltage and if I remember correctly a "Fuel circuit failure". Don't have codes in front of me but mechanic said all those sensors can't go bad at the same time so he said it's most likely the ECU or the Fuel Pressure Regulator.

The Explorer doesn't run good intermittently now, it runs bad and rich constantly with CEL lit so something is getting worse.

I ordered a new ECU, probably a mistake before consulting the forum first but the sensors didn't go all bad at the same time. No codes for spark plug misfires (were replaced 7k miles ago.)

I checked all vacuum lines, cleaned all electrical plugs, reset the computer, battey was replaced 1k miles ago.

Anyway, I know it's a long post but maybe someone can tell me what else to check if it's not the computer.

Thank you,
Maciej

 

[MaciekPL87]

Reman ECU fixed the problem! Truck has alot more power and just runs smooth. I'll see if I can get better MPG to the overall 13.95 I've ben getting.

Thanks to the Moderator for moving to proper forum.

 

[shamaal]

Thanks for posting the followup, ECUs do go bad but generally in a catastrophic manner.

 

[93xlt2wd]

Where did you order the new ECU from? I have the same exact truck with almost the same mileage with the same exact problems. It runs really rich and then one day it just bogged out and wont start. I had previously kind of fixed it by reseting the computer and new MAF and O2 sensors. But now I know it is the ECU.

 

[MaciekPL87]

I bought it at Advance Auto Parts. Took two days to come from Tennessee. Write the number off your ECU because there's many variations you can buy. Mine was $148. Good luck!