Cool. Now, does it matter what dircetion and how much to turn the steering wheel?
Also, you said on step #5 after the 45-1 minute to 'stop' the gas pedal. Did you mean 'stomp'.?

When you say control solenoid, do you mean the EVR?

Thanks for all info.

 

It may not matter if you turn the steering wheel or not. Some vehicles have a power steering pressure switch that the PCM wants to see wiggle. When you move the wheel with the vehicle stopped, the resistance against the power steering pump is fairly high -- enough to set off the switch. I would just move the wheel 1/4 turn right, then 1/4 turn left, just in case yours is one of the ones with the switch.

There was a typo in my post. I meant "stomp" where the "stop" is present.

Yes, Ford calls the egr vacuum control solenoid the EVR. The coil resistance should be 20 to 70 ohms. Pull the connector off the EVR and measure with an ohmeter across the two EVR terminals to check.

Next, use a voltmeter to probe between each of the two terminals on the harness connector and ground. One of these should be at battery voltage (> 10 volts). (The other one is pulled down by the PCM to activated vacuum (and thus EGR flow).

 

fefarms is exactly right. I'll add this. I replaced EGR and EVP and got the same thing you did. The next thing I checked was vacuum lines. Going backwards, there is a green line from EGR to EVR. Then a black one from EVR, past the TAB and TAD, around the back of the motor and around to the coffee can reservoir. Then there is a red one from the coffee can to the intake manifold. I tested the green one with a vacuum pump, (pull it off the EVR and pull vacuum with a vacuum pump, see if it holds, this test assumes that the EGR valve holds vacuum), then the black (reconnect at the EVR and pull vacuum at the reservoir connector and see if it holds), then the red (reconnect reservoir and pump at the manifold end of the red one, you'll have to trace). My red line was 100% shot, the can had a hole in the bottom from rust and my green line leaked a little. After replacing everything the EGR works perfect and the light no longer shows up.

I have 3 EVR's laying around and they're all good. I don't think these go bad too often!?!? However vacuum lines are real cheap and easy. The computer says your EGR isn't moving and vacuum is what moves it. If you think your EGR and EVP are good it has to be something wrong with getting vacuum to the EGR at the right time.

 

Hook up the vacuum gauge or pump at the EVR end of those source vacuum lines, start the engine to pull a vacuum and shut it off, see if it holds. You can test the whole source circuit in one easy test.

For anyone that reads this and is working on a 460, I think the coil resistance is higher, There is an additional resistor hooked to the back of the EVR.

 

Maybe I have 3 that are bad? All three slowly bleed off vacuum through the little upper filter under the cap when you shut the truck off. It takes about 30 seconds to bleed off all the vacuum in the reservoir.

 

A 30 second bleed-down in the EGR vacuum circuits should not be critical to their function, in my opinion. Indeed, this might be the normal behavior. If the vacuum dropped to zero in < 5 seconds, on the other hand, that would be an indication of a problem.

 

Mine bleeds down also, I don't know if it is supposed to. I can hear it bleed down.

But that is not the test I was talking about. I meant to hook the gauge to the line that pulls a vacuum on the EVR. Disconnect the vacuum plug from the EVR and stick the gauge in the hose that goes to the coffee can. Start the engine to pull a vacuum, when you turn off the engine the vacuum should hold. That will test all of the lines up to the EVR.

By the way, you guys are great, this may be the best EGR thread yet.

 

Ok, I THINK I maye have found the leak. Seems like the White line going to the MAP ( the map sensor is the one on the far passenger side corner right?) is cracked. It has been repaired before, but not by me. I could hear the leaking and when I moved the line, the leaking got louder. I reapired it and im clearing the codes right now and hoping that that is the problem.

But, how can a vacuum leak cause bad gas mileage?

Thanks.

 

It causes bad mileage because all the vacuum controlled electronic sensors that are designed to make your engine be super efficient, are no longer working correctly. Thus no longer efficient. As a matter of fact non-efficient. I like Ford's color coded vacuum lines but the fact that they're hard plastic that gets brittle over time and crack is a never ending problem. I had an 81 with a vacuum leak and until I found it I wasted gas and was frustrated. Its always the first thing I check now.

Good thread guys. I came across it the other day and have come back to it. I have a similar problem and started the thread about codes 327 and 328. They're related to this one and I'm gonna go out and test the things you've been talking about here.

Thanks again to everyone.

 

Your MAP sensor is one of the main inputs that your computer uses to set your mixture.

 

And if the MAP sensor sees less vacuum than is actually present in the manifold, the computer will think the engine is loaded more than it actually is, and will tend to over-fuel the engine => bad gas mileage.

 

Well, today my truck stalled after a few weeks of not stalling. I pulled codes and code 34 is back!?

Well, tomorrow is work-on-truck day. Gonna work on things from exhaust to electrical to this damn EGR crap. I'm still not giving up on it!!

 

Wow, Now I got a Code 35! Code 33 and 41 are gone. I just now have these 34 and 35. Both of these saying about the EVP voltage being to high... How can that be?

 

Is the valve not closing?

 

Code 34 means the EVP is telling the computer the EGR valve is open, when the computer expects it to be closed. If this is a KOEO code, just check the EVP sense voltage with a voltmeter. It should be below about .5 volt (see earlier post).

If you are getting code 34 in memory only, the EGR valve may be sticking or the seat is dirty. If the valve sticks open, when it is supposed to be closed, the unwanted EGR may create a stalling problem. Another possibility is the unresolved issue of black vs. grey EVP.

Code 35 means the EVP voltage is "absurd". The computer is seeing a value near Vref, when it is expecting that the voltage should never be that high (open or closed). This suggests problems with the EVP sensor or wiring. Again, a steady KOEO code is much easier to deal with than an intermittant memory code.

Black vs. gray EVP again?