EGR trouble

[jb77714]

my poor little ranger is still running like crap. let me give you some background. its a 94 with the 3.0 with 96k on the clock. its had a tuneup within 5k miles.

i keep getting a code 332 (EGR valve opening not detected) and 335 (PFE or DPFE sensor voltage out of Self-Test range).

the DPFE sensor was replaced about 2 months ago. this straightened it up, for about a month. now the truck is running horrible again. when driving the truck, it feels like a trailer hooked to it jerking it back and forwards. it has a really rough idle as well.

i found this link that was posted by Meisk5, and it describes the symptoms exactly.
http://www.niehoff.com/techtips/n_sen.html

today i removed the EGR and inspected it. i used a vacuum pump and the EGR valve seems to be functioning correctly. i cleaned it up the best i could, as well as the EGR tube, and where it attaches to the intake. while in there, i went ahead and cleaned the IAC and throttle body. the EGR vacuum regulator solenoid was swapped from a vehicle with a properly functioning EGR system, but it didnt change anything.

i have done some reading here and have read that the DPFE sensor is a common failure, but i found the link above about misdiagnosing the problem, and looked into the EGR further, and still no avail.

my next step is actually checking the voltage of the DPFE sensor with a multimeter, and use a vacuum pump to check the vacuum lines for leaks. the trucks pretty quiet, and i cant hear any leaks, just the fuel injectors firing.

it could be the DPFE sensor again, but it had to be ordered last time because the connectors werent the same as the one the part houses list for the truck. if they really are a common failure like i have read, this is going to get old fast. i just think its something else causing this.

if anyone has any advice, tips, things to look for, i would GREATLY appreciate any help. thanks guys

 

[almostclueless]

It could very easily be a cracked hose.....or the hoses reversed on the sensor for that matter.

 

[jb77714]

thank you. i will have to check that and report back. i noticed the hoses are loose fitting, and could easily come off. i didnt think it would affect it because its a low vacuum.

edit: went out and switched the lines on the DPFE sensor, didnt change how the truck ran at all. if somewhere is open tommorow, then ill replace the vacuum lines anyway because they have stretched and fit pretty loose.

 

[Bob Ayers]

thank you. i will have to check that and report back. i noticed the hoses are loose fitting, and could easily come off. i didnt think it would affect it because its a low vacuum.

edit: went out and switched the lines on the DPFE sensor, didnt change how the truck ran at all. if somewhere is open tommorow, then ill replace the vacuum lines anyway because they have stretched and fit pretty loose.

The vacuum lines are special high temp lines. You may try cutting the ends off (just the part of the hose that's been on the sensor) and that should give you a tighter fit.

 

[rileysranger]

i have replaced quite a few of those dpfe sensors on a variety of different ford vehicles. if you apply vacume to the egr valve and it moves freely and doesnt leak, and its not all carboned up than it is likely the sensor is shot.

 

[jb77714]

Thanks for the replies. The Ranger is running pretty bad still. i replaced the DPFE sensor today, as well as the vacuum lines. Code 335 went away, now just code 332 (EGR valve opening not detected).

The EGR valve should be closed at idle, so it makes no since why it idles rough. i applied vacuum to the valve today with a vacuum pump and it didnt leak, and i could hear it open and close, which didnt affect the idle any.

ive checked through the vacuum lines and everything seems fine, just the plastic lines coming from the vacuum switch are starting to get brittle, but not all cracked up like my Bronco was.


any other suggestions? i appreciate your help

 

[sam]

jb77714,

This sounds like exactly what I'm going through on a 94 and what I have done with no positive results. Did you solve your issue?

I have:
Replaced DPFE
Checked the EGR Valve, Seems OK,
Checked Vacuum hoses, OK
Replaced EGR tube
Replaced EVR with a used one

Still the 332 code. About the only suggestion I have not tried is to make sure the tube isn't clogged at the point it attaches to the exhaust manifold, or cleaning the EGR tube.

Sam

Sam

 

[jb77714]

well, the rough idle and bucking stopped after a tune up. it had a bad wire. i was pretty suprised, its usually very noticeable when a cyl isnt firing.

the DPFE (335) code went off after we replaced it, again. ive tested the egr valve, ive replaced the EVR. ive replaced the hoses as well as vacuum lines. ive checked for obstructions in the tubes to the exhaust.

i cant remember if its still throwing the code 332. its not my truck its my dads, althought ive gotten to like the little ranger, enough to think about getting rid of my Bronco for one . ill have to check it this week to see if the code is still there, and get back to working on it. i had forgotten about it until i seen this thread.

 

[sam]

Well, I found the issue with my 3.0L EGR system. I ran a key on engine running while monitoring the signal from the EVR to the EGR. Everything worked just as it was supposed to pointing some obstruction in the exhaust flow to the intake. I found the intake so crapped up with carbon that I got no flow. Thus, the computer didn't get any feedback from the DPFE and gave a code (332, low EGR flow). I pulled the EGR and there was no vacuum when the engine was running again pointing to the intake.

I managed to get the chunks of carbon out, and freed up the passage and get good strong flow now. Highway test with no codes.

This engine had 211,000 miles on it and I guess the stuff just built up over time. PITA to get out, about 4 hours of trying everything including a rifle cleaning kit.

Sam

 

[dangerranger4.0-94]

I new help with code 332

I'm having the same problem with my 94 ranger 4.0 I'm getting code 332 and I've placed everything and tested all the sensors for the right voltages. But my EGR vacuum regulated(as long as the key is one) always has 14 volts. It doesn't change as the engine is running. The vacuum regulator works when I take the wire for the computer off and ground that side of the sensor. It then activates and the truck stumbles when the EGR valve opens. But when the wire for the computer is reconnected the EGR does nothing. I've tested everything and the only part I haven't replaced is the computer , which I really don't want to.