Stall/rough idle

[keithcatfish]

First time poster, long time lurker, this site is awesome.

I have a 95, 4.0, 4X4 with a manual trans and 200000 miles. The truck idles VERY rough if it idles at all (stalls a lot). I cleaned the MAF, checked the TPS (resistance changes smoothly), get the proper resistance at the IAC (9 ohms), cleaned the IAC, and get 5 volts going into the DPFE. The EGR solenoid has about the same resistance to air flow as a new one. If I give the truck gas as it begins to stall, it coughs its way up to higher RPM but then the RPM gets lower even if I keep the gas pedal in the same position. I suspect the EGR valve is bad BUT doubt that the EGR alone is causing the thing to barely run. Any ideas?? THANKS

 

[Stranger ranger]

egr=good possibility.
also i've seen fuel pump solenoids do this, as well as bad 02's, but especially bad maf's clean or not.

 

[Lmartin625]

Same Issue

I have the exact same issue. i have an 03 4.oL and same thing is happeni9ng. Very rough idle if at all, I put it in neutral give it gas and the idle comes up, then crashes and stalls. It does it worse as it heats up, first few stops in the morning it runs fine, but then terrible!
I replaced the MAF sensor, but no difference...I am stumped too.

 

[keithcatfish]

I found a big vacuum leak where the EGR pipe meets the intake manifold. Sealed it with some JB weld and now I'm running again. I created the leak pulling on the nut for the EGR like a gorilla and bent the pipe. Now I gotta get the EGR off. So far no amount of leverage and lube has worked.

The idle still varies from 1000 to 2500 rpm and the revs go up and down when I'm in neutral.

 

[Stranger ranger]

are you replacing it?

 

[keithcatfish]

The diagnostic test indicated the EGR was not functioning properly so I suppose I should replace it. I can't get the thing off, I guess I'm up the creek.

 

[Stranger ranger]

why can you not get it off? Did you get all of the bolts off? Tap it with a rubber mallet.

 

[keithcatfish]

I can't get the big nut to move. Lots of lube and an obscene amount of torque and all I've done is bend the pipe from the exhaust manifold.

 

[97ranger4x4]

cut that mofo off!

 

[keithcatfish]

I might have to but I'm worried that I will not be able to get the nut that connects the pipe to the exhaust manifold off. Then I'm completely screwed. That nut looks like a monster to get a wrench on, much less get off.