Where is the best place to locate used parts for a 93 f150? I have a 4.9 5 speed 2wd and need a ECU. What year computers will swap with mine? Thanks!

 

Junk Yard (with an agreement that you keep bringing them back until you get one that works)

There is a code card on the ECU - Providing the whole vehicle is stock, you should match that code.

Jim

 

You'll have to hit the phone book for your local salvage yards.
You'll need to find a match to your existing computer by the numbers.
You should find a number something like "F2TF-12A650-APB" on your ECM. The F2TF means F2=1992, T=Truck, F=Engine management(more or less). 12A650 is just Fordspeak for engine computer and is found on almost all Ford computers. The "APB" or whatever the last 2 or 3 letters are are what counts. The ECM you need can be from a 1992 or 1993.
If you have a California truck, you need an AUA or AUB
For non-California trucks:
APA, APB, and ARB-all interchange.
ASA and ASB interchange.
ATA, ATB, and AEA interchange (sometimes found in E150 vans too)
NA, NB, and NC interchange.
TA is by itself but found on 93-95 trucks.
XA is also by itself and also found on 93-5 trucks.
Note that the interchange does not explain WHY for example XA cannot be used in place of an ATA(or whatever). Such a swap might possibly work if you get desparate, but you're on your own trying it.
Note also you might even have a code not listed. Ford used a buttload of variations and it's not unusual to find a number which "doesn't exist", especially if the computer was replaced by a dealer at some point. In that case you will either seek help from the Ford dealer or take your best guess from the list above.
Good luck. Be aware that although a junkyard will happily sell you an ECM, the won't gaurantee it to be your problem and likely won't give your money back if it fails to fix your truck. Most mechanics consider a computer swap the last resort as the boxes give very little trouble versus the large number of underhood components that do commonly fail. Salvage yards know this and will likely tell you, "you buy it it's yours". Should the box be bad they will exchange it but likely not give a refund.

 

GypsyR, great info thanks a bunch. The ASE mechanic said it was the ECU, but can't find a used one. Are these just plug and play? Can I swap it myself?

 

Yep, Look back behind the inner fender where your tire tool is supposed to be. You will need to disconnect at least one of the battery cables first. Then you just loosen the small (but long) bolt that holds the wiring harness connector tightly to the ECU box. You'll see. The main part of the box is actually under the dash but it slides out through the firewall from under the hood. Replacing it should take you less than 15 minutes. Once you replace it, you should check the codes or have them checked to see if the ECU replacement had the intended effect.
BTW, just because the guy is ASE, doesn't mean he's correct in his diagnosis. In fact even if he is a damned good technician that doesn't necessarily mean he's correct. I've seen some of the best techs I know with all the best diagnostic tools be fooled by this kind stuff of many times. And of course sometimes it is just a simply diagnosed component failure, like maybe the ECU. Keep an open mind, just in case.

 

Finally, some information on the interchangeability of Ford computers! I have been searching for a replacement computer for my 1992 F-150 5.0L with E40D. The number on my computer is F2FT-12A650-AHA. Does anyone know what other computers would interchange with this one? It has been difficult finding such information, but this thread has certainly been helpful.
Thanks!

 

GypsyR's post helped me a great deal. I removed my computer, found the part number and did a search on the net. I found a used computer with a good price and had it UPS'd. Two days later it showed up, I installed it and my truck is as good as new, Thanks GypsyR! I used carparts.com for my search.