95 Explorer flooding, won't idle, O/D OFF now flashing on dash?

[acsthacker]

95 Explorer, with a 94 4.0L. Check engine light has been on ever since I've had the thing. My initial problem was some sputtering when holding a steady speed of 35-45 mph, or lightly pressing the accelerator. A few people told me it was the EGR valve, so I bought a new one and attempted to replace it. Stay with me here, and I know I know, some of my procedure could have been better, but I was pressing for time and wasn't thinking. The EGR valve for this thing has two mounting bolts, then a metal tube coming from the exhaust into the bottom half of the valve. I removed the vacuum line from the top of the valve, removed the two mounting bolts, then tried to break loose the bolt holding the exhaust tube on with a crescent wrench. It would not move at all, though the line started to just barely twist to where the valve would hardly line back up to replace the mounting bolts. I did not break or crack this tube at all. I decided I didn't have the time, leverage, or tools for the job, so I tried to replace the mounting bolts. I could just barely get one back on... the other would not line up at all. I tightened the one down, cranked the truck, and idle was terrible, along with horrible fuel consumption (obviously). O/D Off was also flashing on the dash now. I took it to a shop to have the valve replaced professionally, and when they got the new one on, it ran the same horrible way. You can smell the gas from it flooding and at some point it smokes somewhat. They ran the codes on it, and found EGR OPEN, THROTTLE POSITION OUT OF RANGE, and 3rd Gear ratio incorrect or something. Thing is, when they cleared the codes, the truck ran perfect. Then within 20 seconds, threw the codes again and ran bad. Cleared the codes again and the truck perked right back up. Threw the codes again and ran bad again. Five mechanics have looked at this and aren't sure what to tell me. One said it was the throttle position sensor, but why would that go bad all of a sudden while I was changing the valve? Or anything else? It seems like a problem that happened so fast that it's gotta have a simple fix for it. Lemme know what your thoughts are.

 

[lifted93xplorer]

Did any of the mechanics check the TPS or just say to try one? It does sound like a possible TPS from your initial complaint and you have a code for out of range. I would test it first with a volt meter before replacing. Also, the EGR shouldn't be open at idle so start it and pull the vac hose off the EGR to see if there is constant vacuum. have the fuel pressure checked.

 

[acsthacker]

He unmounted the TPS and used a screwdriver to twist the inside piece to see if there was any change in the way the engine was running. Didn't change. So I went to a junk yard and got one, went back to the mechanic, he plugged it up, screwdriver again, no change. He said maybe I got ahold of another bad one and that I could try buying a brand new one. I haven't done that yet.
As far as pulling the line from the EGR, the five mechanics that looked at it (and don't know what's wrong) tried that, myself as well. There is vacuum from the line.

 

[lifted93xplorer]

Does the engine smooth out with the EGR valve closed? That EGR should not be open at idle especially when the engine is cold, if it's getting vacuum it's trying to pull the EGR open. That will cause it to idle very rough or even stall because it's like a big vacuum leak.

 

[acsthacker]

Even if I didn't do it in the right order, we have tried using a finger to stop up the line off the valve. It doesn't smooth out any when this is done. I've seen some of the bypass options online and tried options #1 and #2, and the only change seems that it stalls out faster.

 

[2000StreetRod]

Test the TPS

1. I agree with lifted93xplorer that you need to test the TPS. You may want to perform my TPS Test Procedure.

2. Check for vacuum leaks where the EGR valve mounts and where the EGR pipe enters the intake manifold. I'm not very familiar with the OHV but I seem to remember there is a gasket that could be loose in one or both places.

3. Clean the IAC control valve and check the electrical connection to it.

4. Clean the MAF sensor with MAF sensor cleaner.

 

[lifted93xplorer]

Find a new mechanic. My wife can test a TPS.

Your mechanic should have done a TPS sweep, not tell you to just get a junkyard part. A TPS is the easiest sensor to check why didn't he check it? As far as the EGR valve goes it's not from a junkyard is it? You didn't move the plunger further open did you, because a motor will not run worse with the EGR closed? In fact, if someone was to pull the EGR off completley and cover the vacuum port in the intake, you would never even know until the check engine light came on. Did any of these super techs at least do a fuel pressure test yet or are they going to tell you the engine is shot? Someone needs to take their tools away, and what classifies a mechanic these days?

 

[acsthacker]

I'll keep checking for vacuum leaks, but that's the main thing I've been looking for. Plus I've pulled the EGR valve off and re-set the gasket along with gasket sealant and mounted it back on. I'll test the TPS and clean the MAF and IAC next and see what that does.
The EGR is brand new, not a junkyard part, and nobody did a fuel pressure test. That's not something I've done before either. What plunger are you referring to, btw?