Issues... Issues... Issues

[Nez'sRanger]

Despite all my efforts, my truck is still not running well. Here, I want to list all that I did to my truck that resulted in the problem, and then go over all I did to troubleshoot. Hopefully with yinz's help, I'll be able to figure this out!
My truck was running well for the longest time, but had a bad oil leak, as well as the classic 2.9 lifter tick. So, one 3 day weekend, I lifted the engine, and proceeded to change the oil pump and the oil pan gasket. I almost had to pull the entire engine out to get the clearance I needed. When I put the engine back in, I redid the starter wire (cause it was bare on multiple points). I also replaced the main grounding cables (also bare and corroded). Well, long story short, I put it all together, and no start. Big surprise, I put the distributor on wrong... Straightened that out, and got it started. Right away, it started surging and stalling like never before. I figured it was because I forgot to plug in a few vacuum lines and sensors, but it wasn't. I had to feed it gas to keep it running. When it was warm, I was able to set the timing.
Since then, this surging while cold problem has plagued me.
In my effort to diagnose what happened, I proceeded to buy a multimeter and start testing wires, starting with the O2 sensor wires, since those were most likely to get damaged lifting the motor. No problems. I tested the IAC, the ACT, the ECT, the TPS, and the MAP. I ended up replacing the MAP, TPS, and ACT (the act only because I coated it in gasket sealant). Minimal improvement. I also replaced the TFI. No improvement.
I also double-checked the grounding points I messed with. No problems. I have less than a half ohm between any given ground on my truck. I just double checked all vacuum lines... No problems. So, last ditch, I replaced the ECU, because the reference voltage was wrong to the ECT sensor (4.6 instead of 5). Still no improvement

I also have a problem while shifting... When I push in the clutch, the engine revs up 500-1000 rpms too high.
Sorry for the length of the post... I'm desperate! Thank you for any help you can offer! At this point I think I may just have to replace harnesses, and cover all my bases.

 

[rusty ol ranger]

Really sounds like a vacuum leak....

 

[PetroleumJunkie412]

Another "out of curiosity" question... Did you use thread sealant on your thread-in sensors?

 

[Nez'sRanger]

Another "out of curiosity" question... Did you use thread sealant on your thread-in sensors?

Yes, Teflon tape

 

[PetroleumJunkie412]

So. That may be part of the problem. IIRC, I think some of them use their threads as a ground source, but I can't remember if that's just the gauge sensor

 

[Nez'sRanger]

So. That may be part of the problem. IIRC, I think some of them use their threads as a ground source, but I can't remember if that's just the gauge sensor

Hmm... That's a thought! I'll check it out!

 

[RonD]

Only Senders use the threads as grounds, sensors all use at least 2 wires so don't rely on engine as a ground

Oil pressure sender and temp sender are the only 2

 

[PetroleumJunkie412]

Thanks, God!

 

[Nez'sRanger]

Really sounds like a vacuum leak....

I've thought that as well... I'm gonna do a smoke test in the next few days. I've checked and rechecked for leaks, but found nothing. Hopefully a smoke test will solve it, or at least rule it out for good.

 

[Nez'sRanger]

Ok. Smoke test revealed there are no leaks, well, besides the smoke that would pour out the carbon canister... Is that normal btw? Either way, I can't imagine it having any bearing on my problem, since it connects before the throttle butterfly, and it's not a maf truck, so no metering issues should exist pre-butterfly.

Gotta keep looking for issues...

 

[RonD]

No, the EVAP solenoid is stuck open and that's your vacuum leak
EVAP solenoid is in the engine bay
Canister will have two hoses
One goes to gas tank
The other goes to the solenoid and then intake manifold, may have a pressure sensor on the line between canister and solenoid

 

[Nez'sRanger]

No, the EVAP solenoid is stuck open and that's your vacuum leak
EVAP solenoid is in the engine bay
Canister will have two hoses
One goes to gas tank
The other goes to the solenoid and then intake manifold, may have a pressure sensor on the line between canister and solenoid

There is no solenoid on my canister. It has always had just a line feeding into the intake. I noticed in my evtm that the 4.0's ecm had an extra pin designated for an evap solenoid, which the 2.9 didn't have.

 

[RonD]

oops, yes it used Ported vacuum, so no solenoid

But how did the smoke get to that port if its on the fresh air side of the throttle plate?

 

[Nez'sRanger]

oops, yes it used Ported vacuum, so no solenoid

But how did the smoke get to that port if its on the fresh air side of the throttle plate?

I'm thinking through the small hole on the butterfly... Hopefully.

 

[Nez'sRanger]

I may have mentioned this before, but this idle problem starts about a minute after the engine is running. From initial start till then, it runs fine. That led me to believe it was O2 sensor related. I've done just about every test I can think of on it...
If I unplugged the O2 sensor, would it force the eec to run in open circuit mode, or would it make the eec think something is wrong?