OK I have been fighting this stupid truck for a month now. I am getting a 31 EGR EVP/EPT circuit out of range, and a 44 Thermacter air system not working codes. After several self tests continuity tests and so on we found what we thought was the problem. We thought that the # 33 pin was burned out on the ECU so today I replaced the computer. I went through the relearn procedure and the truck still falls on it's face and spits and sputters under a load. I have set the timing changed plugs wires etc... And it is converterless. I have done a compresion test also and the truck checks out good, along with fuel pressure. Does anyone have any idea's because I'm about to go to Wal-Mart and buy a for sale sign. I hate to give up but we are out of ideas and getting low on$$$. Any help would be GREAT. 88 F150/302/5spd/4x4 California emissions

 

on the egr valve there is a switch . 3 bolts and a plug it tells the egr to open or close . it only costs 25 to 35 bucks and 5min to change try that .my truck did the some thing and that fixed it goodluck


ryan

 

cali emissions might be a prob but it is probably the sensor on top of egr i used to have that prob and used a egr eliminator because we dont have emissions up here as for the code 44 i believe thats just air pump issue and shouldnt set off lite

 

make sure your egr and AIR system solenoids and getting engine vacuum because at least on my truck they share the same line and and if they are not getting vacuum it could cause those 2 systems not to work this happened to me and it was all because of a faulty vacuum canister

 

31: Indicates that the EGR Valve Position (EVP) sensor signal is less than the Self-Test minimum value of 0.2 volts.
NOTE:
Because the EVP sensor is preloaded when attached to the EGR valve, a failure in the EGR valve causing the EVP sensor to lose preload may also set code 31.
Possible causes:
Damaged EVP sensor.
Damaged EGR valve.
Open harness.
Grounded harness.
Check
Key off.
Disconnect EVP sensor.
Jumper VREF circuit to EVP circuit at the EVP sensor vehicle harness connector.
Rerun Key On Engine Off and Key On Engine Running Self-Tests.
Is Code 35 present (ignore all other codes)?
Yes
REPLACE EVP sensor. REMOVE jumper. RERUN Quick Test.
No
REMOVE jumper.
Key on, engine off.
EVP sensor disconnected.
Measure voltage between VREF circuit and SIG RTN circuit at the EVP sensor vehicle harness connector.
Is voltage between 4.0 and 6.0 volts?
Yes
Check wiring going to pin 27 of computer.
No
Check Voltage at pin 37 of computer for battery voltage.

44: Thermactor air system is inoperative
Possible causes:
Vacuum hoses leaking, blocked or kinked.
Diverter valve, thermactor pump inoperative.
Air Management Solenoid(s) defective, blocked.

Check:
Verify proper vacuum line routing in the Thermactor air system, including vacuum reservoir. Refer to VECI decal.

Check for kinked or blocked vacuum lines.
Check for kinked or blocked air hoses.
Check for disconnected or cracked vacuum lines.

 

Thanks for the input guys I will try the tests and see what I come up with. Out of curiousity where do I find one of these EGR eliminator kits and how do you keep from setting codes without the EGR system present?

 

The EGR eliminator kits are sold by:

http://rjminjectiontech.com/?p=9

I am not sure if you can get the truck passed in California with one of these EGR eliminator kits on it.

 

I have ran all the self tests again and they check out good. I'm not so worried about the air pump but the code 31 is still present. The first solenoid on the left valve cover side I checked with a test light. I used the ground wire off the wiper motor and probed the green wire on the solenoid. The check engine light goes out but then the truck idles like crap and loads up. I tried to remove the egr position sensor and the first bolt snapped. Havent been brave enough to try the other 2. Also I changed over to a plastic vacuum canister out of a 95 F150 because the coffe can style one in mine is rotted could this be causing some headache as well. Thanks for any input guys.

 

When you grounded the EVR solenoid you opened the EGR valve and the engine went lean and that made it idle bad.
Sounds like either the EGR Valve or the EVP sensor on top is bad.
Here is some information on the EVP sensor:
http://fordfuelinjection.com/index.php?p=35

Good Luck

 

Well I have changed the EGR valve and the spark plugs, reset the timing, replaced a leaky gas line and now the light is off. BUT, it is still sluggish, bucks in overdrive, and doesn't idle down right away when shifting or stopping. Could this be the IAC going bad. I have cleaned the throttle plate, checked the PCV and all the vac hoses, everything seems ok. This truck did sit for 2 years, I added STABL to the gas but added fresh gas before running. Could this just be crappy gas or do I need to look further. At one point I was hot rodding on the truck a little and got a wiff of varnish so I guess I just need some more opinions.

 

Make sure you have goo gas in it first and if no change then it could be the IAC or TPS. You should get a code with the IAC if it does not respond to the self-test. You are doing the KOER self test and not just the KOEO test, right?