Have a 1987 Ranger 4x4 with the EFI Lima 2.3 and a 5 speed. Got it last summer because I was anticipating getting a job that might be a 60-100 mile round trip per day to work. That didn't happen until now and I am going to start driving about 110 miles per day starting Monday. My other truck is a 95 F 350 4x4 that gets 11mpg on a good day, so that is why I have the Ranger. When I got the Ranger last summer it had a miss that I was hoping was going to be fixed with a tune-up. Turned out to be low compression on one of the cylinders, so I tore it down and rebuilt the engine. Tinkered with it throughout the summer off and on, but never fixed the problems I am having with it. Just pulled the codes on it today and here is what I got. All of the code explainations are from Ford Fuel Injection.

KOEO Codes.

21 ECT out of self test range 0.3 to 3.7 volts.
22 MAP/BP sensor out of self test range.
24 ACT sensor out of self test range 0.3 to 3.7 volts.
31 PFE or EVP circuit below minimum voltage of 0.24 volts.
53 TPS circuit above maximum 4.5 volts.

CM Codes

22 MAP/BP sensor out of self test range.

The symptoms that it has is it runs real rich. At idle when standing around it it almost will burn your eyes it runs so rich. In the past couple of days driving it around I have put about fifty miles on it and have burned about five gallons of gas. It was starting real hard. I had to push the gas down about half way to get it to start when cold, but now it is starting a little better. It cranks a little, but it will start without touching the gas. When warm it fires right up. After it starts weather warm or cold it will idle rough and idle about 1200 rpm. When driving it it pulls hard when on the gas. At least as hard as a 2.3 will anyway. When idling through town if I let off the gas where there is no load on the engine it will miss and make the whole truck buck and shake. If I let off the gas all the way where there is load on it again it will stop doing it and if I step on it again it will stop doing it. It is very irritating to drive. Now, this thing seems to be having a hard time getting up to operating temperature. The temp gauge will barely get into the normal range on the gauge. I drove it about twelve miles today at about 30 degrees today and checked the rad hoses when I got home and the upper hose was warm, but not so hot I couldn't keep my hand on the hose. There was hardley any pressure in the rad either. I cracked the cap and it hissed a little and I could pull the cap off without loosing any coolant. I put a new thermostat in at the rebuild last summer, but these have been know to be bad at new. Guess I might change it just to be safe. I know that the ECT and the ACT function both rely on the engine being up to operating temperature which maybe could cause codes 21 and 24. I have already changed the TPS and the ACT. Checked the ECT and it checked good. Not sure how to check the MAP sensor. I did change the MAP for one on another truck here, but the condition of the one I put on it is unknown. I get no codes for an O2 sensor, but I have no idea what the condition it is in either. I am going to verify the timing and check for any vacuum leaks tomorrow. I hope I hit on everything and hope you guys can help me shed light on my problems.

Thanks,

Steve

 

Just a few thoughts

- maybe there's a common voltage supply for those sensors
- problem with the supply (might be from the PCM)
- shorted wires
- open wires
- maybe there's a problem with the connector on the pcm or the wiring

- maybe there's a ground problem

You might try a voltmeter to see what readings you get

 

When Checked the TPS, EVP,ACT, and ECT sensors they all had 5 volts like they are supposed to. I grounded my volt meter to the dizzy when I checked them, but the wiring to the sensors for the ground could be bad. I will check that today, too. Just to make sure.

Steve

 

Pulled the connector from the ECU and started comparing the wire colors to the schematic in my Chiltons manual and at the sensors and the colors don't jive. I am guessing the Chiltons manual is messed up, but i would like to compare to the real thing to be sure. The number on my ECU is E5TF-12A650-J1B and my harness numbers are E77B-DC and there is a 12A581 and a E498K-7A on the sticker on the harness. Wondering if anyone can verify if these numbers are supposed to be in truck in the first post and give me the propper pinouts for the ECU with the wire colors too if you have them.

Steve

 

ford2go, It was a ground problem for the TPS, MAP, and ECT sensors. When I got this truck the wiring was a mess. When I was trying to clean up the mess I connected the three sensors together and missed connecting them into the harness so they would be read by the ECU. DUH. Oh well, was a pretty easy fix for that. Runs better now but now perfect. Checked timing and it is good. Can't find any vacuum leaks anywhere. Took it for a drive and pulled codes on it again. Here is what I got:

KOEO

31 PFE or EVP circuit below minimum voltage of 0.24 volts.

CM

18 SPOUT circuit open or spark angle word failure.

KOER

31 PFE or EVP circuit below minimum voltage of 0.24 volts.
41 No HEGO switching detected always lean (right side).
13 Cannot control RPM during ER Self-Test low RPM check.

I can see where the code 31 is coming from. The EVP doesn't check right. I get about .08 volts at idle or KOEO. I don't know if it is the EVP or the EGR valve. I have another used EVP that I will try on it to see if it will change anything. I cleaned the EGR valve good when I had the engine out to rebuild it. It seems to work ok. I can put a vacuum line on it and suck on it and open the valve and hear it snap shut when I release the vacuum. Seems to hold vacuum and not bleed down, too. This one has the light grey EVP on it. Is it supposed to have the light grey or the black one?

The code 18 might be from when I pulled the SPOUT to check the timing maybe. I checked the SPOUT circuti and it is good, so I am not sure what else it might be.

I have a new O2 sensor on the way. When it gets here hopefully it will fix the code 41.

Have no idea what causes the code 13. I can't seem to get it to idle down and idle steady. After the drive today it idled down to about 1000rpm according to the tach in the dash. Not too sure how accurate it is though.

I am mostly concerned about the code 31 about the EVP. What do you guys think would be the best way to go about fixing this?

Let me know what you guys think.

 

I can say this with relative certainty. When the MAP dies, the idle is rough and the engine will shake all over the place.
You are also not getting a signal from the O2 sensor. "low== lean" When the O2 is working, it will send a low voltage signal to indicate a lean condition. A high signal is close to 1.0v. Check to see that the wires are connected and not burned by laying on the exhaust manifold or pipe.
Code 13 means that the IAC could not lower the rpm or raise the rpm when commanded. It may be dirty or stuck. Clean with O2 safe cleaner, can't hurt... Off the truck, not installed.
tom

p.s. When you set the timing, you disconnected the SPOUT, right? Set at 10btdc at a warmed up idle, spout disconnected.

 

[QUOTE=tomw;8412047]I can say this with relative certainty. When the MAP dies, the idle is rough and the engine will shake all over the place.
You are also not getting a signal from the O2 sensor. "low== lean" When the O2 is working, it will send a low voltage signal to indicate a lean condition. A high signal is close to 1.0v. Check to see that the wires are connected and not burned by laying on the exhaust manifold or pipe.
Code 13 means that the IAC could not lower the rpm or raise the rpm when commanded. It may be dirty or stuck. Clean with O2 safe cleaner, can't hurt... Off the truck, not installed.
tom

p.s. When you set the timing, you disconnected the SPOUT, right? Set at 10btdc at a warmed up idle, spout disconnected.[/QUOTE

When the MAP was disconnected it was idling very rough. Now that I have it hooked up again it does idle smooth. Don't have a MAP code anymore, so I am assuming it is working correctly.

I checked all of the wiring the other day when I had the ECU harness off just to make sure the wiring wouldn't be an issue and it checked out ok.

Took the IAC valve off and checked it out. I know it is not stuck. I tried to spray it ont with carb/tb cleaner and it didn't seem to do much for what was it it. It wasn't gunky, but looked like it had a light carbon buildup in it. Not sure it it is dirty enough to cause a problem. When I pull the connector when the truck is running the idle will slow down and get a little rough. Plug it back it and it smoothes out.

Yes, I pulled the SPOUT when I set the timing. That is where the code 18 came from I am guessing.

Drove it more yesterday and the idle is smooth now, but it still doesn't seem to idle down like it should most of the time. Also, when it warms up when sgoin through the gears if I am in town holding a steady speed in say third gear it will sputter and seem like it is missing. It will do it for about 30 seconds to a minute then smooth out nice. As soon as I shift up or down it will do the same thing. Like everytime I let off the gas it will do it again. Only when it is warm though.

Steve

 

had the same symptoms on a 88 ranger i used to own and it was a bad tps

 

TPS is new and I double checked it and it is working fine. Hopefully the O2 sensor that I am waiting on will help a little.

Steve

 

No wisdom to add, other than to be sure to clear the errors from the memory to be sure you aren't seeing any old codes.

 

Yeah. Did that. Had the battery disconnected when I was checking the wiring harness. Will disconnect when I replace the O2 sensor to see if it clears the code 41.

Steve

 

The O2 sensor most likely will not affect a 'sputter'. It adjusts the air fuel ratio +/- to the point where there are no "extra" oxygens floating around. It is a 'trim' adjustment, and generally not enough to cause the engine to miss.
You could check your spark plug wires. I had a set that would trailer-hitch going down the road at a steady speed. The only way I found out was to look under the hood when it was dark out. Light show, to say the least. I had thought it was the EGR, as when I plugged the vacuum line to the EGR diaphragm, the trailer hitch went away. Apparently it added just enough to the mix to make it hard for the plugs to fire with the worn out wires. Replaced the EGR and I still had the problem. Replaced the wires, and the problem evaporated.
tom

 

It has new wires on it. They are a cheap set though. Guess it wouldn't hurt to check the plugs again. When the other sensors weren't working they were all black because it was running so rich. Kind of wanted to check them again since it is running better anyway. Will check the wires while it is running to see if there is an arcing problem. Thing is it only does it when it warms up. When it is cold it doesn't do it.

Steve

 

When it is cold, a properly running system will enrich the mixture a bit to make sure it has enough 'vaporized' to mix with the air. That fact can be enabling it to run when cool. Once it warms up, the ECM lowers the fuel flow, leaving a mixture that is a little harder to ignite. So, you have a sparking problem of some sort.

On the other hand, the EGR is disabled when the engine is cold. Try running it with the vacuum line to the EGR solenoid plugged with a golf tee. It will likely throw a code for the EGR not responding to commands, but you will be able to tell if it helps.
tom

 

How much actual running time do you have on it so far? I'm thinkin that part of it could be that the rings aint seated quite yet