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Since I bought my '89 302 Bronco I noticed a slight surging while cruising and sluggishness and surging on acceleration. No detonation though. I grabbed a code 32 which is low voltage reading from the EGR position sensor which is on top of the EGR valve. This was the only code. I cleared the code and drove it for a few days with the same problem. Got the same code again. The sensor provides data to the processor so it subtracts the EGR flow from the total mixture equation. Sound right? So my question is could this $30 sensor be causing my problem? I have cleaned the throttle body and IACV. Ignition is in good shape.
Sounds right, but may or may not be the sensor. You also have an EVR (EGR valve regulator), EGR valve itself, and some vacuum lines to check. I've tested or replaced all the components, and still have my miss on acceleration. Several others have gone thru the same drill with no change. Restricting EGR flow to the manifold by use of a blockoff plate sporting a smaller hole has worked for some. There are many EGR threads on the various boards--if you have the time, read them for some more background & knowledge. Good luck.
My Haynes manual has gone missing on me, so I can't tell you for sure. On a '90 5.8 it's on the driver's side, on top of the motor but on the driver's side of the upper manifold. On the 5.8 it's mounted on a bracket with two other solenoids/relays, but it's the one with a green, hard plastic vacuum tube running from it to the EGR valve. I'd be tempted to go the junk yard and pull one off another truck, or a Mustang, or any Ford before I shelled out the money for a new one, especially since we still haven't tied down the correct test procedures for the EVR. Good luck.
The EGR vacuum solenoid controls the opening of the EGR. EVP sits on top of the EGR and tells the computer the position of the EGR. I am going to put a vacuum on the EGR today and observe the output voltage on the sensor. If I have low voltage or not an increase or decrease in relation to the travel of the EGR valve, then I could assume the sensor is bad.
It tested bad so I bought a new one and put it on and reset the computer (disco the battery for 5 min). I drove it for 10 min. with no prob yet. I will have to drive it for 1/2 hr for a problem to show up again.
[updated:LAST EDITED ON 19-Apr-02 AT 06:14 PM (EST)]BroncoScott, is there a filter in that EVP? I had read somewhere that there is a little air filter in the EVP that can get clogged and cause the device to malfunction. It can be removed and cleaned, IIRC.
No, the EVP aka exhaust valve position sensor, is a sealed elect. sensor. This sits on top of the EGR valve. It has a rod that extends down to the top of the EGR valve. The rod is pushed up and down with the valve. FYI check the supply voltage to the sensor. It should be a little over 5 volts.