Code 334
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4wd Low
Joined: Apr 2023
Posts: 12
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Code 334
Hello, I have a 94 e350 sd. it idles ruff and wans to died when first push the gas. i have cleaned egr, replaced map sensor, tested evp and is good, can not find any vaccum leakes. Any ideas where to go next?
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Joined: Jul 2020
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From: Near Salt Lake City
The EGR, if malfunctioning (valve open at idle) will kill the motor
Not at tip in throttle (give it a little gas)
Check the fuel pressure
The code 334 is most likely the EVP sensor malfunctioning (the potentiometer sitting on top of the EGR valve)
Testing the evp and it is good? does not mean it reads the correct value when it is supposed to be closed
You need to be able to read the PID (parameter identification data) from the EVP (and perform the pinpoint test steps for code 334)
Not at tip in throttle (give it a little gas)
Check the fuel pressure
The code 334 is most likely the EVP sensor malfunctioning (the potentiometer sitting on top of the EGR valve)
Testing the evp and it is good? does not mean it reads the correct value when it is supposed to be closed
You need to be able to read the PID (parameter identification data) from the EVP (and perform the pinpoint test steps for code 334)
Thread Starter
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4wd Low
Joined: Apr 2023
Posts: 12
Likes: 1
Hey Manicmechanic007, thank you for responding! The motor did not die when I gave it gas, when you are stopped and try to take off it almost dies. Fuel pressure was 40 with key on engine off. Whrn I turned on engine it dropped to like 39. How do I read the PID info? Thanks agin for your time.
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Joined: Jul 2020
Posts: 10,315
Likes: 2,579
From: Near Salt Lake City
I read pid info using my NGS
Your 94 is smart enough that I can run a bunch of them
You might need to borrow a scanner or see what one of the OBD1 ones will do (most likely nothing) as my Super Star II does not read pids (the NGS predessor)
So, We (us Ford techs) have been back probing connectors for years to eliminate the breakout box
The EGR pinpoint test diagnosis for that code 332 for instance has you measure the EVP voltage after installing the breakout box IIRR
With NGS you just read that pid
You can backprobe your connector if you lengthen and skinny up your test leads for your DVOM
I soldered, brazed actually, nails to nuts that screw on my leads (I can ruin a connector in a few minutes now), just kidding, be careful
I think I have those pinpoint tests and you need the voltage number, I'll post them, but from photo of page, that is the best I can do with my PCED
Looks like the spec is .24volts with the valve closed
Also no breakout box for that code 332
Your 94 is smart enough that I can run a bunch of them
You might need to borrow a scanner or see what one of the OBD1 ones will do (most likely nothing) as my Super Star II does not read pids (the NGS predessor)
So, We (us Ford techs) have been back probing connectors for years to eliminate the breakout box
The EGR pinpoint test diagnosis for that code 332 for instance has you measure the EVP voltage after installing the breakout box IIRR
With NGS you just read that pid
You can backprobe your connector if you lengthen and skinny up your test leads for your DVOM
I soldered, brazed actually, nails to nuts that screw on my leads (I can ruin a connector in a few minutes now), just kidding, be careful
I think I have those pinpoint tests and you need the voltage number, I'll post them, but from photo of page, that is the best I can do with my PCED
Looks like the spec is .24volts with the valve closed
Also no breakout box for that code 332
Hotshot
Joined: Jul 2020
Posts: 10,315
Likes: 2,579
From: Near Salt Lake City
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Hotshot
Joined: Jul 2020
Posts: 10,315
Likes: 2,579
From: Near Salt Lake City
Just realized you are chasing 334 (not 332) and need to start at DN 20
Pay particular attention to what 20 and 21 are saying to you
So you do need the breakout box, or to backprobe the connector while hooked up
Pay particular attention to what 20 and 21 are saying to you
So you do need the breakout box, or to backprobe the connector while hooked up
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