I have a 1988 F250 4x4 351W 5spd. I have been having some running issues. SO I got onto oldfuelinjection.com and did the self test. I came up with some code but need help. I have no clue as to what they stand for. Also here is a little more info on the truck. It has dual tanks. Previous owner made the rear tank inoperable. He replaced the front tank but I don't believe he put in a new fuel pump. It has the pump on the frame rail for high pressure, but will die on me if I get below 1/4 of a tank. Acts like it's running out of fuel. Second this truck ran good all winter. Now we get into the warm days and it wants to die on me. I have to let it cool down. If I remove the gas cap on a hot day after driving it I will hear a hiss. Like pressure being released. I did replace the cap. The new cap you can blow or suck thro that center hole freely but I still will have a hissing sound.

Ok onto the codes. If anyone can explain them that would be great. I repeated the test a few times to make sure I was getting the same codes and didn't miss count the CEL flashes.

KOEO
32 = EVP circuit below minimum voltage of 0.24 volts.

KOER
21 = ECT out of self test range 0.3 to 3.7 volts (This code only came on once)
44 = Thermactor Air Injection system Inoperative. "right side" (My air pump and all the plumbing is still on the truck and works from what I "see". Pump still spins ect.)
77 = System failed to recognize brief WOT during Dynamic Response Test. "user error". (Am I the user that messed up?)

Anyways any help would be great on better understanding what my truck is telling me.
Also My CEL will flash as I drive durring the winter, if it's raining or on a cold engine. It will not flash while I'm driving if I put the trans in N and coast, or when it is warm outside and no rain. It flash at random with no pattern that I can tell. There for a week it would stay lit for 30 sec when I would let off the gas to shift.

 

These were specific to your truck.

Actron®

32=Exhaust Gas Recirculation Valve Position Pressure Feedback Voltage Lower Than Expected

21=Engine Coolant Temperature Higher Or Lower Than Expected

44=Air Injection System Inoperative Bank #1

77=Insufficient Revolutions Per Minute Change Dynamic Test

 

Thank you ncranchero for the link, just I'm still wondering if these codes mean much or not. From what I have read the Air injection system can be removed with no ill effects. So I am not to worried about code 44 unless I need to be. Code 21 is probably because the engine wasn't up to "operating" temp. Code 32 Is the EGR valve going bad? #77 has me at a total loss.

 

Code 32 can be caused by an open EGR position feedback circuit, bad EVP sensor or a collapsed EGR diaphragm/spring.

Code 21 is usually caused by not not warming up the engine before running any KOEO or KOER tests.

Code 77 is usually caused by the operator during the KOER tests. Either they did not blip the throttle at all or not enough.

Code 44:

Possible causes:

-- Vacuum hoses leaking, blocked or kinked.

-- AIRB/AIRD valve, AIR pump inoperative.

-- AIRB/AIRD solenoid(s) damaged, blocked.

Resolutions:

-- Verify proper vacuum line routing in the Secondary Air Injection (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.

 

EVP info: Fuel Injection Technical Library » EGR Valve Position sensor (EVP)

 

rla2005, Thank you for the info. For code 77 was I suppose to blip the throttle? It did raise the rpms on it's own. Went from 800 rpm, to 1500 rpm, to 1900 rpm, then 1700, 1400, back to 1700 then she dropped to 900 rpms.

 

Yes, you were supposed to blip the throttle during the KOER tests. Cut from Oldfuelonjection.com for Code 77: System failed to recognize brief WOT during Dynamic Response Test (user error).