Bad DFPE?
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Member
Joined: Mar 2002
Posts: 29
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From: Calgary, Alberta, Canada
Bad DFPE?
Not another EGR question!!!
I have been trying to track down the famous pinging problem on my 97 f150 4.6L. I have been checking the egr system today. The EGR valve and passage ways seem to be clear since the engine runs rough when a vacuum is applied to the egr valve. There seems to be some suction coming from the vacuum that connects to the top of the egr valve. The egr selenoid has voltage at the connector (12V) and it tested at 34ohms.
The DPFE voltage for the REF was 5V, and SIG is at .75 at idle. While driving the SIG Voltage will vary from .75 - .1V. From what I have read the voltage should increase. Does this sound like a bad dpfe sensore? I have the older style metal DPFE sensor.
I haven't had the CEL turn on.
Thanks for the info.
I have been trying to track down the famous pinging problem on my 97 f150 4.6L. I have been checking the egr system today. The EGR valve and passage ways seem to be clear since the engine runs rough when a vacuum is applied to the egr valve. There seems to be some suction coming from the vacuum that connects to the top of the egr valve. The egr selenoid has voltage at the connector (12V) and it tested at 34ohms.
The DPFE voltage for the REF was 5V, and SIG is at .75 at idle. While driving the SIG Voltage will vary from .75 - .1V. From what I have read the voltage should increase. Does this sound like a bad dpfe sensore? I have the older style metal DPFE sensor.
I haven't had the CEL turn on.
Thanks for the info.
Technical Article Contributor
Joined: Oct 2003
Posts: 1,490
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From: Topeka Kansas
The 4.6L engine is know to have deposits form inside the intake plenum that go to the EGR valve.
You might be able to take a peak into the intake plenum by removing the rubber intake at the trottle body and opening the throttle plate.
If it looks like the ports have buildup then pull off the intake plenum and clean it if. I bought gaskets when I cleaned mine and ended up replacing the intake plenum/intake manifold gasket along with the EGR gasket.
You might be able to take a peak into the intake plenum by removing the rubber intake at the trottle body and opening the throttle plate.
If it looks like the ports have buildup then pull off the intake plenum and clean it if. I bought gaskets when I cleaned mine and ended up replacing the intake plenum/intake manifold gasket along with the EGR gasket.
Last edited by temp1; May 25, 2004 at 09:26 PM.
Thread Starter
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Member
Joined: Mar 2002
Posts: 29
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From: Calgary, Alberta, Canada
Ok, I did some more testing. I applied vacuum to the ref port of the dpfe and the voltage jumped up to 4V. When applying a vacuum to the EGR valve the voltage will also jump up to 4V.
What does the higher voltage mean to the computer? Not enough exhaust gas, or too much gas entering the intake?? From my testing it looks like a higher voltage means too much gas entering the intake. If that is the case there is nothing wrong with my egr system. My Haynes manual doesn't seem to agree with this.
Anybody else confused???
What does the higher voltage mean to the computer? Not enough exhaust gas, or too much gas entering the intake?? From my testing it looks like a higher voltage means too much gas entering the intake. If that is the case there is nothing wrong with my egr system. My Haynes manual doesn't seem to agree with this.
Anybody else confused???