Code message for 1988 FI 460
Thread Starter
|
Junior User
Joined: Sep 2004
Posts: 57
Likes: 1
Code message for 1988 FI 460
Just read the error codes for my 1988 EFI 460 engine. Only one I got was "evaporative control system below min voltage". So how do I fix that, or is it really worth being concerned with? Thanks.
Randy
Randy
Thread Starter
|
Junior User
Joined: Sep 2004
Posts: 57
Likes: 1
Code 31. It was displayed twice, both times the engine was not running but up to temp with the ignition on. There are two memory types the scanner displays with the ignition on but engine not running. Both types displayed code 31.
Randy
Randy
Fleet Owner
Joined: Oct 2005
Posts: 20,789
Likes: 1,753
From: Kentucky
Yes, I am fully aware of the KOEO test display and codes from Continuous Memory (CM) aka historical.
Code 31 (KOEO): EVP circuit below minimum voltage of 0.24 volts.
Code 31 (CM): EVP circuit has intermittently failed below minimum voltage of 0.24 volts.
This code indicates the closed EGR signal is below 0.24VDC. This can be caused by a faulty EGR Valve Position (EVP) sensor or the EGR valve itself can be bad. The EGR internal spring pushes up against the diaphragm which preloads the EVP sensor. This is a bit difficult to diagnose because of this interaction. It's a matter of process of elimination.
Remove the EVP sensor, watch carefully as you lift it off the EGR valve. There should be some movement of the EVP sensor shaft as it lifts off it's mount. If there is very little then I would go with a new EGR valve. If there is some preload then the EVP sensor is probably bad. Sometimes it's a combination of both parts causing the issue.
Code 31 (KOEO): EVP circuit below minimum voltage of 0.24 volts.
Code 31 (CM): EVP circuit has intermittently failed below minimum voltage of 0.24 volts.
This code indicates the closed EGR signal is below 0.24VDC. This can be caused by a faulty EGR Valve Position (EVP) sensor or the EGR valve itself can be bad. The EGR internal spring pushes up against the diaphragm which preloads the EVP sensor. This is a bit difficult to diagnose because of this interaction. It's a matter of process of elimination.
Remove the EVP sensor, watch carefully as you lift it off the EGR valve. There should be some movement of the EVP sensor shaft as it lifts off it's mount. If there is very little then I would go with a new EGR valve. If there is some preload then the EVP sensor is probably bad. Sometimes it's a combination of both parts causing the issue.
Thread
Thread Starter
Forum
Replies
Last Post
court1100f
1987 - 1996 F150 & Larger F-Series Trucks
16
Mar 30, 2011 11:03 AM
whiteyfordzx5
1987 - 1996 F150 & Larger F-Series Trucks
7
Nov 22, 2005 11:44 PM
Timken
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
4
Feb 12, 2004 06:14 PM
