Doesn't this HAVE to be the EGR Valve??

Originally posted by Contouraholic:
You probably can't suck hard enough to operate the EGR

Of course you can. It takes less effort that does drinking a milkshake through a straw.

5.1:

The 327 IS an electrical problem. You are close to the right track, but you have a slight misunderstanding of how the EGR system works.

In a nutshell, here is how it is supposed to work:

1. PCM tells EVR (EGR Vacuum Regulator) solenoid to open, applying manifold vacuum (restricted) to the EGR valve.

2. EGR valve opens, allows exhaust gas to pass through air tube, EGR valve, and intake.

3. The exhaust gasses pass by an orifice in the air tube enroute to the EGR valve. There are sample tubes connected to the air tube on each side of the orifice. When there is EGR flow, there is a difference in pressure/vacuum between the two sides of the orifice.

4. These tubes are connected to the two inputs of the DPFE ( DIFFERENTIAL Pressure Feedback EGR) sensor. The DPFE sensor outputs an analog voltage that is proportional to the difference in pressure/vacuum between the two sample tubes. This voltage is fed back to the PCM as an input to tell the PCM how much EGR flow is taking place.

5. The PCM can, under its programming, vary the duty cycle to the EVR solenoid, which varies the EGR flow rate which is reported back to the PCM by the DPFE sensor.

Basic closed loop feedback control system.

Now to your 327 code:

This indicates that the output voltage of the DPFE is below the lower limit of 0.2 V when there is no EGR flow (lower limit is around 0.45 V).

There is a simple test to see whether the fault is due to the DPFE sensor or an external fault, however, the physical location of the DPFE sensor and its connector on the 2.5L makes it a challenge to perform.

1. Key off. Disconnect the connector from the DPFE sensor. Jumper the Vref wire in the wiring connector to the DPFE circuit (consult your schematics for exact wire color codes for your year/model - I can't read the wire color codes on my service CD drawing) on the wire harness connector.

2. Re-run the KOER test and watch what codes are output.

3. a: No codes generated - wiring harness or PCM fault

b: 337 code - DPFE sensor bad

c: 327 code again - check Vref circuit to the DPFE sensor for an open circuit (loss of Vref to the DPFE sensor)

There you go - the tools to DIAGNOSE the 327 code you are encountering. Good luck.

FWIW, my bet is that after you fix the 327 problem, you will still have at least one additional problem code that will then crop up. Unfortunately, you will have to fix this problem first.

Steve

Thanks Steve,

But, if you go by the way that you describe the EGR system, which I believe to be correct, than the DPFE sensor can have absolutely NO effect on how an engine runs.

Why? Because all your saying is that the DPFE tells the PCM how much EGR flow there is, but you're not saying that this information actually CONTROLS EGR flow. So if all the DPFE sensor does is tell the PCM how much EGR is flowing, how can a bad DPFE sensor cause an engine to stall??? If the DPFE is simply a feedback sensor, and the PCM does nothing based on this info, a bad DPFE would cause nothing other than a DTC.

I also go back to my original question: If the vacuum supply to the EGR valve is disconnected, and the problems persist, than how can the problem possibly be an EVR or DPFE problem? To me, a DPFE reading low would cause the PCM to command too much EGR flow(because it thinks not enough is occuring), and as a result, there would be constant vacuum going to the EGR valve. BUT, disconnecting the valves vacuum supply SHOULD quickly reveal whether this is the case or not...correct?

THANKS MAN!:)

The DPFE does not directly control anything on the engine. Only the PCM does that. Normally, there is NO EGR flow at idle or at WOT. It is entirely up to the programming within the PCM as to whether or not EGR flow is commanded based on the operating parameters built in to it.

As to your repeated question, please refer to my last comment above regarding multiple problems.

You will have to clear the reason for the 327 before you can intelligently proceed further.

I suspect your DPFE is defective, but you also have an additional problem, perhaps caused by the extended period of time that the condition causing the 327 has been there. Possibilites include a stuck open EGR valve, faulty IAC, or some other intake vacuum leak.

Steve

Quote:

I suspect your DPFE is defective, but you also have an additional problem, perhaps caused by the extended period of time that the condition causing the 327 has been there.

This is actually exactly what I was thinking. I thought that perhaps the EGR valve keeps getting stuck open because after I clean it all up, the DPFE will than cause an over active vacuum supply...resulting in extra carbon build-up etc.

?

Well, the computer is what causes the EGR valve to open, not the DPFE.

In any event, get rid of the 327 first.

Steve

why not just take the EGR valve off and then clean it out with carb. cleaner and put a vacuum on it to make sure the vacuum section controls the valve.... then you can blow into one end to see if the valve really closes or stays open when you want it to... and there are test you can do on a DPFE or any sensor for that matter with a plain old multimeter/volt ohm meter.. i downloaded a operating manual from the web site for Sunpro by actron III digital multimeter, but the instructions can be used with just about any multimeter.... go to
www.actron.com and look up manual on the left side of the screen for actron products, multimeter... its about 36 pages long i PDF format.. you need acrobat reader to view it.. hope this helps... i need to check out the DPFE on my 93 taurus, getting the bad codes for that also... but it should work on any dpfe sensor...

Not true. I operated mine with just my personal facial vac - no problem.

You have the basic proceedure right. If you apply vac, the engine will run rough(er) & possibly stall. That is IF you have an EGR that is operating properly. You should also be able to crimp the hose while the vac is applied & hold the rough(er) idle. This will tell you if the EGR has a leak in the diaphram.

If you EGR passes these tests, then you replace the DPFE. The original is an aluminum box about the size of a Zippo lighter on the block, just below the EGR valve. The newer ones will have a black plastic housing. Each will have an electrical connector, two hoses, and two bolts holding it on the block. A simple repair made tricky because of tight access.

It is my theory that the new DPFE housings are made from recycled water pump impellers.

PLEASE NOTE:

When you replace the DPFE, you will want to perform a TB cleaning. A simple & cheap proceedure - Your wrenches, one small screwdriver, $4 gasket, $3 for TB cleaner (do not use carb cleaner). You MUST be CERTAIN to clean the EGR channels behind the TB gasket (probably stuck to the Upper Intake Manifold).

These clogged channels may be part of what caused the DPFE to fail.

IN FACT, YOU MAY WISH TO CLEAN THE TB PROPERLY FIRST. This may restore EGR flow & raise the DPFE voltage & rid you of your problem - without replacing anything.

Originally posted by TourDeForce:
Not true. I operated mine with just my personal facial vac - no problem.

Hehe, then you may have another career opportunty in personal services..
J/K

I prefer using a hand operated pump with gauge. I can control the vacuum and check for leaking diaphragms too.

Hehe, then you may have another career opportunty in personal services.. Ouch!!! You'll pay for that!...Um, I mean I'm gonna get your @ss!!...No, wait...I'm gonna beat you!!...No, no good...Crap, forget it.

I grew up a poor farm boy in Northern Maine. Vac pumps were unheard of. Besides, I couldn't justify buying a gauge if I could just buy a length of vac hose for $1 and also have spare tubing whenever I might need it. Ain't I the industrious Boy Scout.

I didn't have one till fairly recently. I have the little Mighty-Vac (Metal One) with the brake bleeding accessories. My wife could never get the hang of pump, hold, release (Not what your thinking, I am talking about brake bleeding). If I get frustrated enough explaining the problem, she says to buy the tool that makes it easier and then I won't need to yell so much!

It's easirt to bleed brakes with the vac pump then using "facial vacuum" to do it.

BTW, I think you coined a new term. I have never heard it called Facial Vacuum before. Funk and Wagnalls may be calling you this minute...

I'd never put a vacuum on my brake system. I use a simple one way check valve thingy from the auto parts store. One man brake bleeding kit.

My wife could never get the hang of pump, hold, release (Not what your thinking, I am talking about brake bleeding). If I get frustrated enough explaining the problem, she says to buy the tool that makes it easier and then I won't need to yell so much!

yes, thats why i bought the mighty vac also at autozone for about $25, the plastic one, but it works good...
i never could relay how to pump the brakes when under the car and just about gave up..until the mighty vac..
you might also be insterested in the :
Speed bleeders: http://www.speedbleeder.com/

I seem to be having the same problem on my 95 mystque V6.Where is the d.p.f.e. located? All I can see is a senser located on the rear of the u.i.m. two vac. lines,one from the e.g.r. and elec. conection,this senser is a round barrel like object.Does the d.p.f.e. go buy any other name because I have not found a listing for it in any parts books
thanks

Originally posted by mkrog:
I seem to be having the same problem on my 95 mystque V6.Where is the d.p.f.e. located? All I can see is a senser located on the rear of the u.i.m. two vac. lines,one from the e.g.r. and elec. conection,this senser is a round barrel like object.Does the d.p.f.e. go buy any other name because I have not found a listing for it in any parts books
thanks

The round, barrel shaped piece you described is the EVR solenoid.

The DPFE sensor is below that on the firewall side, buried way the heck under everything else. Look down from the IAC valve.

The DPFE often goes by names that include the following keywords: EGR, Pressure, Sensor . For example, AutoZone's site calls it the "EGR Valve Pressure Sensor" - $53.99 for a Wells SU282 for a 98 2.5

Steve

Well here's an update:

Today I went over and for the first time saw just how bad the car was acting.

Here's what would happen:

You start the car, it revs up to almost 3000 RPMs, then, if it doesn't stall right away, it will just keep going way down to ALMOST stalling, and then SHOOT right back up to 3000 RPMs, and then go back down and ALMOST stall, and then SHOOT back up etc...etc...it would keep doing this like 10 or more times while idling until eventually it would just completely stall out.

Now, I finally bit and decided to buy a nice vacuum pump so that I could test the EGR valve out.

I first tested it with the engine OFF to see if the valve would hold vacuum. I pumped it to about 10" hg and it held there for well over a minute. So it passed that test.

Then I started the engine and applied 10-12" hg of vacuum to the EGR and it made absolutely NO difference at all!! I kept applying vacuum and then releasing it, applying and releasing...and the engine didn't respond at all!!

So, is it safe to say that there's a crap load of carbon that is not allowing the EGR valves diaphragm to close??

I just find it strange that the engine acted like it had a mind of it's own, constantly reving up and down, up and down, just about stalling and then shooting the RPMs way up...I think it made it a lot worse because the outside temperature was well below Zero, and we all know that the PCM doesn't even activate the EGR until it's reached operating temperature.

THANKS GUYS!!:)

PS Is it true that I pretty much NEED a 22mm Crowfoot wrench to remove the valve??

Originally posted by 5point1:
Here's what would happen:

You start the car, it revs up to almost 3000 RPMs, then, if it doesn't stall right away, it will just keep going way down to ALMOST stalling, and then SHOOT right back up to 3000 RPMs, and then go back down and ALMOST stall, and then SHOOT back up etc...etc...it would keep doing this like 10 or more times while idling until eventually it would just completely stall out.

This is a whole different ballgame. This does not sound like a DPFE or EGR problem at all. I'm thinking the Idle Air Control valve needs a good cleaning.

If I was the guy spending the money, I'd do the TB cleaning, and start the car up to see if that helped. The channels behind the TB gasket are probably so caked full of carbon that you can't even see them.

If that doesn't help, its a simple task to remove the IAC valve to clean & lube it. THAT should get your idle smoothed out real nice. Maybe you can get a CEGer to visit you & let you install their working IAC valve. That way you know if it will solve the problem before you spend money on one - if needed.

Both these things can be done in one afternoon by a novice mechanic in the cold northern air (although I'd let the IAC valve dry off indoors before re-installing it).

Quote:

This is a whole different ballgame. This does not sound like a DPFE or EGR problem at all. I'm thinking the Idle Air Control valve needs a good cleaning.

But my sister just had these exact same symptoms about 3 months ago. She took it to a mechanic, and they cleaned the EGR valve which cured the problem up until now. The mechanic told her she would eventually need a New EGR valve though...

??

Originally posted by 5point1:
You start the car, it revs up to almost 3000 RPMs, then, if it doesn't stall right away, it will just keep going way down to ALMOST stalling, and then SHOOT right back up to 3000 RPMs, and then go back down and ALMOST stall, and then SHOOT back up etc...etc...it would keep doing this like 10 or more times while idling until eventually it would just completely stall out.

Not sure about what's causing your problem, but this is the car searching for an idle. It is reving and falling through the range until it finds a comfortable idle. The car is unable to find an idle, and then stalls out.

Good luck.

- Zack

You checked the diaphram in the EGR valve & it appeared to be good - except for the Engine on test. This tells me that the EGR passages to the TB are all plugged up. Clean those beasties out!!

Once done, be sure both hoses & the electrical connection to the DPFE are secure and start the car. It may be all you need. If the engine is still hunting for idle, clean the Idle Air Control valve.

Those two things should set things right, you don't have to purchase anything except a $4 gasket & some cleaner. Even if the DPFE has gone belly up, the idle should not be affected that radically. I had to replace mine after a TB cleaning to rid myself of a dreaded CEL & my car never even ran poorly.

Give them a try, you have next to nothing to lose (assuming you do it yourself).

if this is the case why would you even post here... just take it off and clean it or put a new one on... oh, i get it, maybe if you keep asking for help you will find the answer you want???? what answer do you want??? the mechanic looked at it and saw the EGR.. no one here saw it so how do you expect someone here to do a better job of troubleshooting it than the mechanic who saw it???
If you put a vacuum on the top of the EGr and it pulls a vacuum then that is only telling you that the diaphram does not have a leak.. you pull a vacuum when the engine is running and if it does not run rough or kill then its not working at all.. could be a small piece of carbon holding the EGR stuck or the inside vacuum chamber of the EGR might even be blocked up??? but when the background you have on this the cheapeast solution is to take it out and clean it up....then if you have the same problem then it is not the problem???? if it the code goes away then you know its the EGR... then you replace it, like your sister should have done in the first place....
i never had a 22MM crows foot wrench, but did have some old a/c refrigeration wrenches.... used a 1 1/8 in. open end flare wrench to get to the tube on the EGR... was worried about it breaking, but it was just a little over hand tight, one little bit of force and then it could be removed by hand... boy what a relief...... i looked all over for the 22mm wrench and could not find one at pep boys, autozone, sears, etc.. i knew i could have ordered one from
NAPA or someother supply house, but did not want to spend too much for a wrench that i would never have used again...
hope this helps.