What's left?

[Rosberg1]

Here's my problem. I've got a 90 ranger with a 2.9. For some reason after driving it a ways it will miss or just fall on its face and will do it more frequently the farther I drive it. It misses a little at idle too. My check engine codes are 22,23, and 67. Which are MAP out of self test range, TPS out of self test range, and clutch switch circuit failure. I've replaced both the TPS and the MAP and nothing has changed. Also, when driving the check engine light goes off until I push the clutch in to change gears. So far I've replaced the TPS, MAP, FPR, Injectors, fuel filter, fuel pump, O2 sensor, several vacuum lines, the exhaust, the IAC valve, and rebuilt the top end. Is there anyone here who has experienced this and if so how did you fix it?

 

[armadillon]

Sheesh, you did a good amount of replacing stuff. Definitely don't give up yet. Just curious, have you done cap and rotor/plug wires/plugs recently?

 

[Rosberg1]

Oh yeah, I forgot those on my list. I did the plugs and wires but the cap and rotor were new when I bought it. I inspected them for cracks and corrosion but they were mint.

 

[armadillon]

I doon't have the 2.9 so please excuse my ignorance if you don't have one of these: On my 89 5.0 I DID have a problem similar to this where after a while it would just die on me. There was a module or sensor underneath the rotor on the distributor. Also the ignition control module would give me sh*t as well

 

[laminad]

Does it fall on its face when giving it gas but runs fine as soon as you start to let up. Mine did that and I found it was the dash ground. Mine was on the windshield wiper motor. Go figure.

 

[Rosberg1]

That is EXACTLY what it does. It seems I may have some wires to check. That may be the random rigged wire whose purpose is unknown. There is another real ground wire attached to it but doesn't seem to reach anything.

 

[Rosberg1]

Grounded the wire, reset timing properly, and test drove with and without the spout and received the same result.

 

[Psychopete]

Is this a truck you just purchased? Some history can give some clues.

What is your TPS reading voltage wise at idle and WOT? The screw could be turned in too far by someone who thought that was an idle adjustment screw to make it run "good enough." Check ref voltage to MAP, make sure your engine vacuum is acceptable, and you may want to replace the vacuum line to the MAP sensor.

Were these KOEO, CM, or KOER codes?

 

[Rosberg1]

I purchased it back in December with this issue for 500 bucks. I'm new to this engine and when I first got it I turned the screw thinking it was an idle adjustment. These were KOEO codes, TPS was tested KOEO. I'm reading .709-.714 at idle and 3.944 at WOT, voltage in is 4.46 now that I tested using the ground at the TPS. Tried adjusting it to get .9 volts and had to turn it all the way in.

 

[Rosberg1]

MAP reference voltage is 4.3 KOEO

 

[Rosberg1]

So I ohmed the harness between the ECM and the MAP and TPS and everything spec'd out. I'm thinking the ECM is bad?

 

[Rosberg1]

LOL, I just cross referenced the code on Oreiley's website and the previous owner put a 2wd computer in it.

 

[Earl43P]

I don't think the 2wd computer matters.
I can mail you a 90 2.9 4wd automatic computer if you want it.
PM me your address. You pay me back shipping, that's it.

http://www.therangerstation.com/tec...es/Diagrams_ElectronciEngControls2_9_2of3.JPG <shows those two circuits tied together, minus the clutch switch/CEL deal. That sounds squirrely.

 

[Rosberg1]

Yep, somewhere along the way they share both the orange/ white (power from ECM) and black/ white wires (ground). Its a manual, thanks for the offer though. I'm sure the 2-wheel 4-wheel doesn't matter, its just funny to me because it seems this thing was built almost entirely of spare parts. The other day I was underneath it putting a new muffler on it and noticed it had 3 different brands of shocks on it and the rear axle is narrower than the front by 2.25 inches!

 

[Psychopete]

How far closed is the throttle plate? That voltage is awfully low. Given the top end has been gone through and IAC is replaced, check the engine vacuum no doubt. If idle is high with throttle plate closed, there's a vacuum leak somewhere. What happens when the IAC is disconnected at idle? I wonder if the computer has this open all of the time for some reason(??) It's tedious, but capping each off each vacuum tap one by one might be something to try.

Vacuum leak is going to screw up MAP readings. That's why it's important to check the engine vacuum to make sure the MAP is getting a good vacuum signal.

TPS is probably set too low, which is causing the other code.

Also definitely get the engine up to temp and run a KOER test.