Code 31..? "EVP below minimum voltage"

Reply Subscribe

Thread Tools

Search this Thread

Jan 29, 2006 | 08:38 PM

eco

Thread Starter

Posting Guru

Joined: Jan 2006

Posts: 1,263

Likes: 1

From: The dark carnival

Code 31..? "EVP below minimum voltage"

I finally was able to get the codes out of my truck (thanks to everyone here), and all I got was a "code 31."

I replaced the EVP and nothing changed.

The truck will NOT run @ less than 1500 rpm. Would this sensor cause this, or is something else going on that the computor does not have a code for?

Thanks

Feb 6, 2006 | 06:57 PM

i6powered92

New User

Joined: Jan 2006

Posts: 3

Likes: 0

From: stl. missouri

that code means your egr valve position sensor (evp) is bad, which you already knew i dont know if that can cause high rpm but i had a vaccum leak at one point that caused it to idle at 2,000 rmp. you can find the leak by following all the vaccum lines and pray them with wd-40, carb cleaner, etc and when you spray if the rpm's fluctuate then you have found your leak. hope that helps

brandon

Feb 6, 2006 | 11:36 PM

russt

Senior User

Joined: Oct 2004

Posts: 102

Likes: 0

you changed the wrong part - you need to change the sensor on top of the eger valve -that might help with the rpms -if not check the iac valve ( try spraying carb cleaner thru it - just make sure the carb cleaner is o2 safe) most are nowadays.

Feb 8, 2006 | 07:40 PM

puck1263

Senior User

Joined: Oct 2005

Posts: 342

Likes: 1

only use a motorcraft EVP. Other brands may give the computer wrong voltages. Check yours at closed position and open position and make sure they are within spec.

As with the idle, that is something else. I smell vacuum leak. Check your engine tempurature sensor just in case.

Feb 9, 2006 | 01:06 AM

eco

Thread Starter

Posting Guru

Joined: Jan 2006

Posts: 1,263

Likes: 1

From: The dark carnival

I am not saying that the idle speed is @ 1500 rpm, I am saying that I have to open the throttle plates to raise the rpm to 1500 in order to keep the engine running. So, I don't think that I am dealing with a vacuum leak.

I replaced the EVP (the one on top of the EGR valve) and the EGR valve and the code went away. But, the problem with having to rev up to 1500 to keep the engine running did not go away.

Coolant temp sensor...? If there was a problem there wouldent the EEC throw a code? I will check it out.

Thanks

Feb 9, 2006 | 07:45 AM

puck1263

Senior User

Joined: Oct 2005

Posts: 342

Likes: 1

Ok, in that case ignore the previous diagnosis.

Check (voltage, resistance) and clean the IAC. It is a large cylinder with an electrical connector on the side of the TB near the air intake. The function of the IAC is to do what you are doing manually. Take it off the truck and deep creep the hell out of it on the inside. There are many posts regarding this topic.

Feb 9, 2006 | 08:36 PM

eco

Thread Starter

Posting Guru

Joined: Jan 2006

Posts: 1,263

Likes: 1

From: The dark carnival

The IAC is brand new (NAPA Echlin) so I don't think that it needs cleaning. It measures 10.5 ohms accross the 2 leads, so it's good there...I don't know about voltage though. I will have to look into that.

Things that are new: TPS, Coolant Temp. sensor, Air Temp. Sensor, EGR Valve, EVP, O2, IAC, Thermostat, Knock Sensor, Fuel Pressure Regulator, Engine, Transmission, Fuel Injectors, MAP and more.

Still working on this.

Thanks.