Hi to all, cold and snowy here today. Problem with 1990 F150 5.0 was a bad EEC. Changed it out with a used one and truck runs, just misses pretty bad. I,ve done the obvious, new plugs, wires, cap etc. and still misses. My question is, does the replacement EEC need to be flashed? Here are the numbers from the old one: E9TF-12A650-AL2A C9Z 60ES20BF09 17459-756 9L27. Replaced unit numbers identical except for last four digits of the last line.
Thanks for any and all help.
Trimman1224

 

There is no "flashing" on this vintage PCM.

 

Sounds like the computer wasn't bad after all. Have you done a compression test? What about codes?

 

Computer was definitely bad, truck would not start and fuel pumps would not run prior to changing it. Compression in all cylinders is great. As for codes, I don't have a reader and it is missing so badly I'm afraid to drive it into town at this point. Has poor power going down driveway. My '89 f150 2wd would run circles around it. As soon as the roads are cleared of the snow, I'll try towing it to a mechanic in town and let him check codes. Also, no vacuum leaks can be found. Will post results of that test. Thanks for responses. Trimman1224

 

You can pull codes without a reader, just need a paper clip and the ability to watch the flashes of the check engine light. Search for how to do this.

 

Fuel Injection Technical Library » How To Run a Self-Test

Try warming up the truck before running the KOEO tests and stored code display. Otherwise you will trigger a few out of test range sensor errors.

Fuel Injection Technical Library » 2 Digit Self-test Codes 11-32

 

Many thanks for those two links, Randy. It's 8 below outside now but I will do this self-test today and post results. Once again, many thanks. Trimman1224

 

What are the last four alphanumeric digits of the replacement ECM? There's 15 different ECMs showing for a '90. Would need Calibration code stamped on the inside door jam to match. What transmission does it have? Is the replacement ECM a junk yard part? Did you open it up to check the board? Could have swapped for a dead PCM for a half-a** PCM.

 

You have changed plugs and wires so are you certain you have them routed in the correct order? This motor should have the 15426378 firing order with #1 cylinder at the passenger side front and cylinders are numbered 1234 front to back on pass side and then 5678 down the drivers side. Distributor turns counter clockwise. If for some reason that doesn't work try the HO firing order.. 13726548.

 

At 12 below in the shop this morning, things went kinda slow, especially me. Pulled some codes using flashes of service engine light, they are as follows with each dot representing 1 second pause: 1..1....1..1....1..111....1..111....1 did this three times to make sure!
Old EEC Numbers:
EECIV EFI-SD20b 32K EPROM
E9TF-12A650-AL2A gC9Z
60ES20BF09 17459-756 9L27
Replacement EEC Numbers:
EECIV EFI-SD20b 32K EPROM
E9TF-12A650-AL2A gC9Z
60ES20BF09 15899-58 9H04

Calibration code from door jamb:
9-54E-R10 E9AE-6E061-CDS

Sorry, for the confusion of the EEC numbers almost matching, was going on memory from many weeks ago.

Truck is a 1990 F150 Lariat XLT 5.0 extended cab shortbed
Tranny is from the working 1990 F150 truck the replacement EEC came from and is an AOD, I bought the entire truck for parts, especially the tranny, as the body was pretty ragged out from ranch use and abuse.

I just installed a new fuel pump regulator, PCV valve, distributor cap, rotor button, plug wires, water pump, timing chain and gears, oil pump, new pan gasket, new seals front and rear, steering gear box, steering column, dash assembly with tach, new brakes all around, new fuel pumps in both tanks, new fuel filter, transmission, transfer case, seats, bed liner, wiper motor, new tires and probably many other things I just can't think of now. Truck ran great for a few weeks until this missing started. Great compression all around with a 5#+/- difference in cyls.
Being 4x4 it will be used primarily to haul potable water for our cistern and to get me to the fire dept in all types of weather. Jump seat works great for storing firefighter gear bags. My 1989 F150 reg cab is 2WD and can only be used to haul water in the summer here.
Hope the above info helps someone to help me figure out what's going on with the truck. Thanks in advance. Trimman1224

 

I forgot to add that I am certain the plug wire routing is correct and I am using the proper firing order. Also the replacement EEC was opened up and no signs of smoke or leakage was observed. Circuit board looks brand new.
I still have my first 1990 F150 5.0 as another parts truck, can you ever have too many? I think I'll pull that EEC and check it out as well. That truck runs great, but AOD tranny is dying, also the body is rusting out badly. I'll post those EEC numbers once I have it in hand. Thanks guys, Trimman1224

 

I just pulled the EEC from my original 1990 F150.
It is an ASE re-manufactured unit. No bar code sticker on it, only the ASE label with the following info:
Number 8-4269
DC Code 0804AV
I'm going to install this one now just for the "fun" of it. Hope it works.

 

So I posted a question about a problem I was having. I get responses asking for certain information. I post all of that information in detail and I get no response. What gives?

 

Probably just that the people who were helping you simply ain't been back on the forum since then, or if they have been, they just missed your thread when going thru the main thread listing. Give it time... I'm sure somebody will be along to help you out!

 

Well, let's summarize this.

Title question, "does the replacement EEC need to be flashed"
Answered in post # 2. No

2nd question, truck runs poorly/misses, (post #1 and #4)
Info requested post #3

Compression verified and codes checked. List of components changed. Post #4 and #10. Codes appear to be 11 and 13. Info on interpreting codes given in post #6.

Calibration info requested post #8. Appears to be answered post #1, #10, and #12. Nothing concrete here, but appears to be a dead end.

Suggested that ECU would be swapped with known good one. Post #12. No results reported.

So, we have to assume the poor running/miss condition still exists.

I do not think this is an ECU problem. That vintage of EFI was batch fire injection and if you were missing 1 of your 2 injector pulse signals, things would be much worse. I'd look for a problem with individual injectors, possibly a clogged nozzle or a wiring problem on top of the engine. Use the so called "noid lights" to verify you have a signal pulse at each injector. Check your fuel rail pressure. I see you have changed the fuel pressure regulator and filter. All good, but you must actually measure the pressure with a gauge to verify fuel system integrity. Check the injectors for spray pattern.

There always is a chance of component failure, even with new components. Go back over your ignition system and check for any problems. Have you checked your exhaust system for restriction? Plugged catalytic converter or collapsed pipe? Clear codes and see if anything reoccurs. Is timing set to spec? How about the intake air filter?

Seems to me everything may already have been covered. No other great insight on my part as to what the problem may be, but good luck with it!