Current EGR disconnect, can I leave it like this?

[rocket22]

Over the past 6 months I have had the CEL light on and the codes from a 1995 (OBDI) are indicating EGR. (I dont recall the code number) I replaced the EGR and the problem continued: Rough idle, surging at low idle, and kinda sluggish. I removed the vacuum line from the top of the EGR valve (Leading the the EGR Solinoid) and plugged it and the engine ran fine, great idle, no issues with performance. I figured it was the EGR Control Solinoid (connected to the plastic intake) which I changed and connected everything up. It ran rough as before so I removed the new EGR Control and reinstalled the old one. (I didnt have a testing method for it). I have also changed plugs, wires, air filter, cahnged vacuum lines, and tested the IAC.

Two questions: What could the problem be? I will pull the codes later.

Is there any issue with running it like this? Bottom line is the EGR wont open and some of the gas wont recirculate so I wont pass emissions, which isnt required by a pre 1996 in Illinois. I use this for towing and local stuff, so i am perfectly fine driving like this

(Note: please no replies about destroying the ozone, the truck still has a cat and I am sure my lawnmower kicks out more pollutants.)

 

[NHale623]

The problem could be the DPFE, also known as the EGR Valve Position Sensor. They are a common failure.

If you search this forum, you'll find lots of hits regarding the DPFE.

 

[aldive]

I second the DPFE.

 

[rocket22]

but can I leave it like this?

What is the harm? i will look up the fix

 

[budwich]

"No harm, no foul"... except for the clean air types and you may get "pre-ignition" on those hot days, heavy loads which the recirculating gases are supposed to help. If its severe, you may cause engine problems.

 

[Turdle]

Your truck will burn an excessive amount of fuel while in "open loop" mode.

Whenever a "CEL" is displayed, the PCM is in open loop mode. In other words-your truck is limping.

The cost for the new part will quickly be eaten up over and over again due to inefficiency. In fact-just a short 30 mile round trip could cost 3.00 too much in fuel alone.And, as fuel prices rise higher and higher-well, the new part seems to be a bargain to me.

Not to mention the shorter engine lifespan. ( EGR gasses cool the upper ring and valve seats also)


So, can you LIVE with leaving it?
and BTW
Your lawnmower burns a gallon of fuel per hour max--maybe once a week.


it doesn't even compare to a vehicle---

 

[rocket22]

I stand corrected

THe funny thing is when the EGR is hooked up in present condition the rough idle and surging kills my miles, the truck is getting better milage now. Would a failed DPFE cause a rough idle? I do want to fix the problem and the truck is a great tow mule and hauler for what I need it for. No rust, just some little quirks.

Is there a good test for a DPFE to check functionality?

 

[Turdle]

First thing's first.
Get the codes pulled and write them down-

without them we are shooting in the dark--

 

[aldive]

Is there a good test for a DPFE to check functionality?

Take a look at http://rockledge.home.comcast.net/~rockledge/RangerPictureGallery/DPFE-Voltage-Test.html

 

[rocket22]

I will pull the codes again this weekend

I have the OBDI code reader for this 1995 truck, the connection is under thr hood, exactly what does he connection in the vehicle do? Was it jus t a precursor for the OBDII connection? It does not pull codes with my cheap OBDII connector

 

[NHale623]

THe funny thing is when the EGR is hooked up in present condition the rough idle and surging kills my miles, the truck is getting better milage now. Would a failed DPFE cause a rough idle?

The EGR valve opening when it shouldn't be will cause the symptoms you describe. A failed DPFE will cause the EGR valve to open when it shouldn't. When you disconnect the vacuum line from the EGR valve, it stays closed.

You really need to understand what the EGR system does, and how the components work. Here are a couple of links to get you started:

http://www.fordscorpio.co.uk/egr.htm
http://free-auto-repair-advice.blogspot.com/2007/08/understanding-ford-dpfe-and-egr-system.html

 

[rocket22]

Got the basics

I am familar with what the EGR does, but I think a vacuum gauge is the much needed tool in this equation. I am aware that the EGR open is giving me the rough idle, the question is others have had the failed DPFE and have not reported the same idle issues. Could a failure of the DPFE keep the EGR closed all the time and hence why some do not have the same issues when this part fails?

The rise in gas prices is a concern and I want to get this truck in peak operating condition. If I have time tonight I will pull the codes and post here tomorrow.

The advice I got on the Solinoid over the DPFE was from an ASE mechanic, but as we all know they can be wrong and do not have the exposure to explorers that this site has. Thanks for all the advice and direction, I look forward to see the truck start and not having the CEL illuminate 1 minute into the drive.

 

[AMMO_HOOAH]

I'm assuming that if it could fail in one direction then it could fail in the other, but that's just my opinion.

 

[NHale623]

I am familar with what the EGR does, but I think a vacuum gauge is the much needed tool in this equation. I am aware that the EGR open is giving me the rough idle, the question is others have had the failed DPFE and have not reported the same idle issues. Could a failure of the DPFE keep the EGR closed all the time and hence why some do not have the same issues when this part fails?

Maybe, maybe not. You don't know if your DPFE has failed or not. If the failure kept the EGR valve closed, you would expect codes regarding insufficient EGR flow. In other words, it wouldn't open when it should. Your symptoms imply the EGR is open when it shouldn't be.

The problem is, we don't know what the codes are.

What do you think a vacuum gauge is going to tell you?

 

[fa1921]

I have a '91 and I am having the same problem... CEL comes on after it warms up and starts shifting hard/stalling out and the codes are 33 , 53 , 84, 34 and 41

Can you just unplug the EGR???

replaced the solenoid with no prevail...

 

[rocket22]

sorry need to clear up my thoughts here

I wanted the vacuum gauge to do some testing of the individual parts acording to one of the EGR testing threads. I will pull the codes this weekend and will post here.

 

[fa1921]

Oh boy! 2 digit codes! I am really going to have to search the memory on this one.

Okay:The 33 is EGR not opening. That could be a bad egr valve, either the valve sticking or not holding vacuum. Use a vacuum pump and apply vacuum to the valve, with the engine running. You should notice the engine start to run rough. If it does then the valve is okay and you will need to check the vacuum lines to the valve or the EVP sensor (EGR valve position) is bad. If you are getting vacuum to the egr valve, I always replace the valve and sensor together. And always use a factory EVP.

The 53 is Throttle Position sensor above max voltage. That is a bad t/p sensor.

Both of those codes are hard fault codes.

The 34 is the EVP sensor above closed voltage. That is always a bad EVP sensor or the incorrect one. (again use factory parts)

The 41 is the O2 sensor not switching staying lean. That is normally either a exhaust leak above the O2 sensor, a vacuum leak at the intake manifold somewhere (the upper plenium gasket is common) or a bad O2 sensor (really common).

The 84 is a EVR circuit failure code and that could be either a bad wiring harness of a bad engine control computer. I have not seen too many wiring problems. But I have had to replace the computer for that code.

I hope that helped.