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Discussion Starter #1
Ok I tested my EGR voltage and it runs .62 volts at idle/part/full throttle. I doesn't seem to move

I tested the EGR on my wife's V6 stang and it was at 1.06 volts at idle and went up to 2.5volts during part throttle. These are general figures; had to drive ya know.

No codes regarding this have been thrown on the car, but I am having some trouble with a high idle when my TPS voltage is at 1 volt if that is remotely related


Question:

1. Should I take the car to the dealership and have Ford check out my EGR system?

2. Does my EGR reading vary from what any of you have experienced.


Anyone with an autotap I would appreciate your results, Thanks.

Dennis
 

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DS97Cobra said:
Ok I tested my EGR voltage and it runs .62 volts at idle/part/full throttle. I doesn't seem to move

I tested the EGR on my wife's V6 stang and it was at 1.06 volts at idle and went up to 2.5volts during part throttle. These are general figures; had to drive ya know.
What kind of EGR feedback do you have? EVP, PFE, or DPFE?


In any event the not moving bit is a clue. It should change with varying load on the engine. Now this does not necesarily mean the the sensor is bad although that may ultimately prove to be the case. It kinda suggests that the hoses to the PFE (I'm guessing here) are cracked and split. But I would think that a visual inspection would've turned that up.

The EGR system uses vacuum going to a solenoid which in turn connects to a vacuum operated EGR valve. Loss of vacuum due to a cracked hose is the usual culprit. Next on the list is a bad EGR valve diaphragm. Followed by a stuck valve pintle shaft. if you got as far as pinpoint testing of the sensor voltages then testing actual valve operation should be a piece of cake.

Another thing I've noticed is that 4.6's have a penchant for clogging up the EGR passages in the intake. It's usually clogged to the point of requiring physical cleaning.

Those are some ideas to check for and if it all checks out then I'd be looking at a defective sensor, myself. HTH
 

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One other point most posts I have read on the subject say the TPS voltage should be .98 volts maybe yours is a tad to high??
Will it make any difference who knows?

Dwayne
 

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Discussion Starter #4
What kind of EGR feedback do you have? EVP, PFE, or DPFE?
I actually backed the tps voltage back down to .98 so to avoid a check engine light for high idle. I was told 1 volt by John Mihovitz


In any event the not moving bit is a clue. It should change with varying load on the engine. Now this does not necesarily mean the the sensor is bad although that may ultimately prove to be the case. It kinda suggests that the hoses to the PFE (I'm guessing here) are cracked and split. But I would think that a visual inspection would've turned that up.
I pulled it off and tried to clean it last night. Little hard to clean well due to the small areas. I was able to move the piston via my handy allen wrench.

I actually didn't check the hoses. I didn't see any electronics on the Valve piece itself, just a vaccum line, so it is good to hear it is vaccum operated. I will check the vaccum line for splits and cracks tonight back to its source.

How do I check valve operation? Suck on the vaccum side hole?

Thanks!!



Anyone have EGR voltage logged via an autotap????? That would be really handy!!
 

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Discussion Starter #5
ttt
 

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OK, I have more time now. The rugrats got home just as I opened the reply window :D


Anyway I also re-read your first post. I was under the impression that you were trying to diagnose an EGR code. A little closer attention to the actual problem and I realize that you're after a high idle. So all that EGR stuff is not necessary since that won't cause a high idle. The most you'd notice out of an EGR system failure is a Check Engine light. Well, perhaps some surging in certain instances.

A high idle is usually related to a high TPS voltage at closed throttle. Some cars are more sensitive to the closed throttle setting than others. How high of an idle is it? 2000rpm? 1100 rpm? If its like 1100 or so I'd be looking at a TPS situation. If its 2000 then you may have a defective Idle Air Bypass Valve.
 

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Discussion Starter #8
A high idle is only a symptom I am experiencing when the TPS Voltage is set at 1 volt. Around 1000rpms. I backed it off to .98 volts to avoid a check engine light. I only mentioned that incase an EGR valve may be related


My question is based on checking the EGR. My voltage reading are nowhere close to my wife's 98V6. It fluctuates a little, but never gets above close to 1 volt.

Also the piston doesn't seem to shut fully when I had it off the car.

I need the voltage reading off another Cobra basically, and a way to check my EGR valve outside the autotap.
 
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