I have a 1994 f 150 xlt 4.9 il 6cyl 4x4 it has a continuous code of 334 I have replaced the e.g.r valve don't know what else to do help please

 

Code 334: EVP circuit above the closed limit of 0.67 volts.

That means the feedback signal to the PCM is too high when the EGR valve is supposed to be closed. This can be caused by a faulty EGR valve (which you already replaced), a faulty EGR Valve Position (EVP) sensor or one other possibility is the EGR Valve Regulator (EVR) is allowing vacuum through to the EGR when it is supposed to be closed.

Get a meter to verify the EVP output signal with the Key On Engine Off, then repeat with the Key On Engine Running. If they match then you probably have a bad EVP sensor. If the KOER value is higher then you most likely have a bad EVR.

For reference:

Fuel Injection Technical Library » EGR Valve Position sensor (EVP)

Fuel Injection Technical Library » EGR Vacuum Regulator (EVR)

 

Egr closed Valve voltAge high is what the code reader says

 

How do I ground out pin 33 ???

 

Use a jumper then momentarily touch the other end to a ground such as the engine itself.

 

Okay I will give it a try thank you

 

So I grounded it out I don't think it opened all I heard was noise coming from that you GR valve so do you think it's the e.g.r valve or the e.g.r valve position sensor both are less than 2 years old

 

Did you meter the output voltage as I suggested before? If not, you are wasting your time and money.

 

That last post was supposed to say it did open when I grounded it out but I also got a noise from the e.g.r valve and the voltage said 11 .2

 

The EVP Reference Voltage is only 5 VDC +/- 3% there is no way the output voltage was anywhere near 11.2 .

The error you have states the closed EGR voltage is too high. What is the EVP output with the Key On Engine Off? What is the EVP output with the Key On Engine Running? (No grounding of the EVR is required)

At this point we are not really concerned with the EVP output with the EGR fully open.

 

It is reading 5.00 volts at idle

 

I think I'm gonna have to find someone with more technical skills than Me I might not have this meter on the right setting heck I'm not even sure if I'm reading it right or not I'll find someone with a little better knowledge of this and I'll get back to you

 

You are really close, put the Red lead of your meter on the Brown/Light Green wire of the EVP sensor. Put the Black lead on the Gray/Red wire. Turn the key to the On position, see what the meters reads when it is set to measure DC voltage.

 

I got no voltage at all

 

That's not good.