4.0 ohv running issues

[Xeek]

So my 94 ranger quit on me a year ago, just getting around to messing with it. It's currently doing the same thing it did back then. Runs pretty good cold. But once it's warm it idles normal but will drop to 400ish rpm at times. No power at all, just barely can get it to roll down my street.

Nothing was changed before it failed before. it just screwed up on its own. The o2s are new-er and I did retorque the intake at some point.

I just changed fuel pump and filter. Also spark plugs and wires. Drove it around and when it decided to bog down I got the following codes:
629(koeo) Torque Converter Clutch circuit fault - Transmissions
566(koeo) transmission 3/4 shift solenoid/circuit - Transmissions
565(koeo) Canister Purge 1 solenoid/circuit failure - Solenoids
556(koeo) Fuel pump relay primary circuit fault - Power / Fuel Pump Circuits
159(koeo) MAF sensor is/was out of range - MAF

177(koeo-memory) Oxygen sensor not switching - system was rich Left or Front HO2S - Fuel control

137(koer) Oxygen sensor not switching/system rich Left or Front HO2S - Fuel control


Was talking with another member on here and he figured MAF, I bought a new one, reset codes, and still have same issue, except the memory code of 177 is gone.

He's thinking a wiring issue? Any other ideas? Tests to preform? Its been so long since ive messed with it i dont really know where to start anymore. Also i noticed i only have a left o2 code, since it's not both maybe it could have a problem with the left one?

 

[974X4BLACKSPORT]

Have little animals that like to chew wiring moved in to your vehicle while it was sitting?

 

[Xeek]

This happened before I let it sit and was driving it everyday. I've just let it sit for the last year past that.

But the only thing I've noticed is all the wasps in my bumpers and mirrors. Other than that it's pretty clean

 

[410Fortune]

So it "runs Pretty good cold"
Does this mean it fires right up and runs smoothly until the water temp rises, then it falls on its face?


Then once warm it idles normal but falls down to 400 rpm and stumbles...no power, runs rough, will barely move on its own


I am starting to suspect the 137 code, 02 sensor not switching, system rich
A not switching issue usually means a dead 02 sensor as long as the fuses and wiring to the sensor check out.
I would start there

Its a good idea to check all fuses
check fuel pressure
so you can rule those out

The 02 sensor should be switching otherwise it will run like this = crap

 

[974X4BLACKSPORT]

Being that so many systems are showing a fault at once, possibly a ground issue, start by making sure the ground connections are in good shape and not broken or corroded, this includes battery to chassis, battery to body, harness to frame and harness to body and frame to body.

 

[Xeek]

So it "runs Pretty good cold"
Does this mean it fires right up and runs smoothly until the water temp rises, then it falls on its face?


Then once warm it idles normal but falls down to 400 rpm and stumbles...no power, runs rough, will barely move on its own


I am starting to suspect the 137 code, 02 sensor not switching, system rich
A not switching issue usually means a dead 02 sensor as long as the fuses and wiring to the sensor check out.
I would start there

Its a good idea to check all fuses
check fuel pressure
so you can rule those out

The 02 sensor should be switching otherwise it will run like this = crap

Yes runs fine cold. I was able to do a little burnout, continued driving as it got warmer then it just lost all power. It's also bogging down in neutral/park.

Surges a bit 500-750ish. And will hold 400ish for a few seconds then climb back up.
When I last drove it last year it was so bad it stalled on me, letting it cool down allowed me to drive a bit more, but not all the way home.

O2 sensor would be my next guess. I did replace them awhile back with new motorcraft ones. Since it's just the one side it's a little suspect. my truck has one on each bank. I plan on picking up a fuel pressure tester today. If you or anyone knows off hand any resistance readings for o2/MAF/etc I'll go ahead and test some of those. Fuel pressure is supposed to be like 30-45 at idle, right?

 

[Xeek]

Being that so many systems are showing a fault at once, possibly a ground issue, start by making sure the ground connections are in good shape and not broken or corroded, this includes battery to chassis, battery to body, harness to frame and harness to body and frame to body.

Might just be worth looking at. It is a lot of codes to have all at once. Was a pain trying to count the flashes with all these codes lol. had to do it multiple times to make sure I had them all correct

 

[Xeek]

So I rented a fuel pressure tester. 0psi across the board. I unhooked it, tried again, same thing. The fpr is dry. Undoing all vac lines makes it sputter even worse so I don't think they're leaking. Unplugging maf it stalls, unplugging iac it idles really bad but runs. And now cold it has it's issues sooner than when fully warmed up. Next up I'll check on the fuses

on the straights i was giving it a good throttle but had some lag before it decided to accelerate some.

 

[974X4BLACKSPORT]

Something wrong with that gauge, engine is not going to run with "0" fuel pressure.

 

[Xeek]

Kinda what I figured. Just went with it anyway since I had the camera going.

It doesn't look like the rangers have the same style battery cable as explorers. I don't have a ground cable going directly to frame and engine. Just to the starter. I can't find the frame/engine ground either, I looked in the same place it was on my 91 explorer and I don't see anything.


Edit, actually 0psi is the problem. I tested with air compressor and it's perfect. Somethings up with the fuel rail. Clogged?

 

[974X4BLACKSPORT]

The shrader valve on the fuel rail could be damaged or clogger I suppose.
You need to make a ground cable to go from the engine block to the body, rubber motor mounts are not good at grounding the block to the frame/body.

 

[Xeek]

Seems that's how the factory neg cable is. I looked online and it doesn't include a thick wire to body and frame, just like a 8-10 gauge wire. There's gotta be a separate one somewhere. I'm eventually gonna run my own cables

I may have found out the issue. But I have to wait til tomorrow to see. Rtv requires drying time lol

 

[Xeek]

So the rtv thing was my intake tube. I noticed a big hole. Wasn't the problem though.i did find out my Schrader valve is clogged, I took it out and conntected the gauge. Constant 30psi while running, driving, bogging down.

I had also taken out the fuel pump again and reseated the hose of it to make sure it was good. And had to get another tank oring as the one that came with the Carter pump was to big for the groove?? Weird, but fixed.

Ran a vac gauge on the tree. I have a 422 cam in here so numbers might not be factory but I was getting 15-17inches of vacuum while running. And also replaced a section of line from the tree to the ac stuff cause it wouldn't hold vacuum. So it should be sealed up now.

Swapped in new relays for fuel pump and eec. No change.

And about the ground issue, there is a frame ground, I just didn't see it at first. It's inline with the one going to the starter/trans bolt

So where to go from here?

 

[410Fortune]

30 psi is a little low
Did you ever address the 02 sensor issue? the 137 code. Until you fix that it is not going to run well
30 psi is low fuel rail pressure should be more like 36-42

 

[Xeek]

Did seem on the lower end. It does go up with the fpr vacuum line removed like it should, for me it goes to 38psi.

I didn't replace the o2, but I did test both. They both read 4.0 ohms on the white wires. Which is within spec for the style I have.

I'm really leaning to clogged up injectors. But if you guys really feel putting in a new o2 sensor will help I'll go for it. I just hate spending money on parts. I have a new maf sensor sitting here I need to return already. I've reset system and the memory code for o2 sensor and koeo code for MAF are gone.

 

[Xeek]

Took them out. Left and right side respectively. The left one doesn't look good but I don't know if it's the sensors fault or something else causing it

 

[410Fortune]

I bet that code comes back with some drive cycles
the white washed sensor is either not preheating or something is a miss upstream (lean?)

 

[Xeek]

New o2 on left bank(they only had one in stock locally), idled ok, ran terrible. Unplugged maf and it was better, still have issues and I think that's how the tranny codes are being thrown, it's getting confused with the weird idle/revving up and shifting at the wrong time.

I had issues that made me lean a bit, so the o2 was richening it up and probably got stuck on rich and broke trying to richen it.

But I doubt that's the case, as I still have the tranny codes, fuel pump circuit code and left bank rich. But now I'm getting a koer of 116, ect out of range.
I had tried running with it unplugged before this code popped up and it still ran bad, the ECT unplugged should kill all values from sensors to ecm and default to open loop.

 

[donalds]

 

[Xeek]

I've done that. I had it like that for an hour cause I got distracted back in the house. With doors open and headlight switch on. All the codes came back without even starting the truck, first thing I did was read codes.