Sorry, but these were definitely three-digit codes. My mechanic (and my 19 year old son) may have their limitations, but I'm sure they can distinguish between three-digit and two-digit numbers. According to the code reader manual, two-digit codes were used up to 1991 on Ford products, and after 1991 most of the Ford codes are three digit.

There are probably differences among code readers (I got mine at Shucks), but the way my son described the process, the three-digit numbers appeared in the digital readout the first time around, along with a blinking light, with the first number repeating itself at the end of the whole sequence of eleven codes. Then for some reason, the eleven codes repeated themselves after a slight pause, but this time only with the blinking light (no digital number readout this time). My son said that it was hard at first to figure out what the code reader was doing, but then he realized that the blinks corresponded to the initial sequence of eleven numbers, with short pauses between each number and slightly longer pauses between each three-digit set of numbers. At the end of this second variation of the sequence, the light just started blinking continuously, with no further action.

According to the manual, what is supposed to appear next is the number "10," which is the "separation code," This separates the Self Test Fault Codes from the second set of codes, which are the Continuous Memory Codes. I don't know why the readout never shows the number "10," and why it never moves into the Continuous Memory Codes. I also don't know why the Self Test Fault Codes are repeating themselves a second time, but without digital readout. One obvious possibility is that the car computer is malfunctioning, but when we bought the truck (which was not running at the time and had to be towed), the previous owner gave us a new computer that was still in the box, which he had been planning to install. So it would be kind of freakish if the computer turned out to be bad.

I can give you the descriptions for the eleven Self Test Fault Codes if that would be useful to you. As I said earlier, they are mainly solenoid circuit fault codes. But as someone said earlier (Dave, Irishguy?), they may not mean much anyway because they may clear automatically as soon as the lowest code in the sequence (the 123 "Throttle Position Sensor Above Maximum Voltage") is corrected. I will try to work on that tomorrow when I can get my hands on the truck.

 

I'm not sure if my last post "took" (I'm a little new at this). If it did, forgive me for repeating myself somewhat in this one.

Athough these were definitely three-digit codes, the code reader manual backs all of you up -- it indicates that most Ford EEC-IV vehicle computers up to 1991 use two digit codes, while those after 1991 use three-digit codes. Is it possible that the wrong computer is installed in the truck? When my mechanic picked up the computer (still in the box, I think) from the previous owner, he may have just installed it under the assumption that it was the proper computer for the vehicle. Maybe it wasn't.

It's curious that the code reader has never acted exactly the way it is supposed to, as described in the manual. It ran through the Self Test Fault codes once, repeated the first one in the sequence again, and then after a pause went through the entire eleven again with just the blinking light (no digital readout). My son said that it was hard at first to figure out what it was doing, but then he realized that there was a short pause between each number (three blinks for three, etc.), then a longer pause between each three-digit sequence. Then when it finished the second time, it just started blinking continuously. What it is SUPPOSED to do, according the manual, is to display the number "10" (the "separation code") after it displays the Self Test Fault Codes, and then start displaying the Continuous Memory codes. It has never given us the "10," and refuses to move into the Continuous Memory codes.

Any thoughts?

 

I also am troubleshooting an older Ranger, an 86. I see you list the engine as a new rebuild, is that a different motor than was in it originally? Is that the same type and size that was in it originally ? And finally, you replaced the computer, Did you make sure it was for the year of the truck and motor ? I asked about the sets of numbers on the computer and was told that they had to match exactly. Here's the thread: https://www.ford-trucks.com/forums/s...34#post2859134
My largest problems turned out to be a plugged cat and the hose that connects the intank pump to the outlet tube was melted. Probably from an additive. Still working on a code 41 and running a test pipe for the cat until my new one arrives.

 

Yeah, I can see some potential here for a mismatch, i.e., new rebuilt engine and new computer, both purchased by someone else before I bought the truck. And the prior owner was not available for any follow-up.

I will certainly check the numbers on the computer when I go down to my mechanic's shop in a few hours, but how would I check the year of the rebuilt engine -- and does it matter? I'm quite sure that it's a 2.9L, but what if it's a '90 instead of an '89, or a '91, etc., etc. How do you tell? (My mechanic would probably know this, but I'm asking just to make sure.

 

I'd be more concerned with the computer and the sensors matching each other and the engine. I'm not sure if there's a difference in the same engine between years. Maybe emission wise. Any Ford manual will show you how to find out.
You might have to call Ford and ask them what the computer number should be for your year truck. With those 3 digit codes that's where I would start. I almost bought one that the last 3 digits were different until I got an answer to my post about it.

 

I agree with Wildpony, you need to get the right computer in there. The engine is probably fine, so long as everything reinstalled ok. The computer needs to be the proper one for the engine/electrical setup for the truck you have. Things change with redesigns, etc. You will probably have to call Ford and check out part numbers. There are several flavors of computers for each model year, you will need to find the right one for your trucks makeup. You can get some information by poking around carparts.com listings for computers for your truck. Good luck figuring it out.

 

Thanks for your continued assistance and good wishes. I spent some time with my mechanic on Saturday and he agreed to pull the computer and take it up to the local parts house so that they could check its compatibility. The code reader manual says that "most" Ford computers up to 1991 have two digit codes, so I suppose there's an off chance that a particular computer manufacturer would produce one with three-digit codes (this one is a NAPA, as is the local parts house). But the code reader doesn't just give three-digit codes; it also has serious problems cycling through the codes sequences (as I've explained) -- which suggests a basic computer malfunction.

Understand that my mechanic has just been poking around the truck during his lunch hours and in between jobs. That was the agreement. So he hasn't been logging in long hours -- although over a six month period they have probably accumulated. I think he has begun to realize, though, that this vehicle had been seriously messed with before I bought it, and by someone who had no idea what they were doing. (For example, a number of wires in various parts of the harness have been stripped and re-taped.) So it's a little different than someone bringing a vehicle in to him that doesn't run quite right and asking him to get it up to speed again. He's good at that, but this has been much more of challenge.

Here's something else a little weird that my mechanic mentioned to me on Saturday. He had another, younger mechanic (factory trained and all that) helping him out with some major automotive projects a few months ago, and just for the heck of it he turned the Ranger over to the young guy one afternoon. The young mechanic's first reaction when he test drove the truck was that that it acted like it had a faulty EGR value, but when he looked under the hood hd couldn't find one. It appears that the intake manifold (which was probably bolted onto the original engine) has a flange and port coming out of the front right side of the manifold (looking front to back), but it is capped with a plate. The two mechanics figured that this is where the EGR value should have been. Does that signify anything, or were EGR valves optional with this engine?

 

1989 2.9s didn't use EGR, Ford stopped it in 87 or 88 and just capped the port.

 

Ken is correct. My 1988, 2.9 has no EGR valve.