2.3L ('83-'97) 1990 Code 32, EVP Voltage below closed limit

[Ceej]

Hello,

I have an issue with a new to me pickup. When I pulled the code, and there was only one, it flashed "32." I found that the hose from the charcoal canister to the bottom of the Throttle Body wasn't actually connected. I got that corrected, but the issue persists.

When I push the truck, at relatively high to WOT settings, the Check Engine Light comes on. It goes out as soon as I let off the long pedal. The only code I've pulled is 32.

Does EVP mean Evap, or does it mean something else? One of the first things I had to do was pull the bed and install a new fill hose. The outer had rotted away. I installed a new fill hose assembly. Could this be a poor seal at the gas cap? The charcoal canister is likely original. It looks a little worse for wear, but the hoses (now) are intact and appear to be sealing up.

So school me on this if I've headed down the wrong path. The truck runs fine, and gets great mileage. I use it for our shop as a parts getter, to which it is nicely suited.

I appreciate any feedback.

CJ
1990 Standard cab short bed.

 

[franklin2]

EVP means EGR Valve Position sensor.

The guy in the book says to disconnect the vacuum line to the EGR valve, put a vacuum pump to the valve and see if the valve opens and closes as you put vacuum to it. Then reconnect everything back up original, and then run the codes again. If the code has gone away, the EGR valve was probably binding.

He says if the code returns again, replace the EVP sensor. Then run the test again. If the code returns again, replace the EGR valve.

Your truck has a EGR vacuum valve controlled by the computer. The computer pulses the valve to open the EGR valve, and then it looks at the EGR position sensor to see if it moved. The sensor is mounted on the EGR valve itself. If it doesn't see any movement, it will throw a code.

I don't know what your EVP sensor looks like, but the picture below shows and example of one. It's the grey part in his hand.

 

[Ceej]

Thank you franklin!

Hooked my vacuum pump up to the EGR valve, and low and behold, it wouldn't pull down. There's a known bad part!

On the way over to NAPA, the front brakes started dragging. A heck of a stink by the time I got over there. So, bought new calipers and fixin's while there.
I won't have time to mess with further repairs this weekend, as we're scheduled through Tuesday. So, back to driving the BB dually & sucking down dead dinosaurs for a few days.

We'll get 'er licked eventually!

CJ

 

[Ceej]

Replaced the EGR valve, and no more codes! Thank you again. A few more cosmetic items, and I've got a driver.

CJ