I have been pursuing and engine control problem for about 5 years now. I just replaced the fuel injectors, and the truck was running rather OK. Now it will fire a few times and die. Sometimes it starts out like the throttle is full open and then die, sometimes will try to run at 300 rpm, and die. I have just pulled the codes and am getting #21, 22, & 31, with inactive codes of #31 & 51. These are supposed to be Engine Coolant Temperature Sensor Input Out of Self -Test Range, MAP Sensor out of self test range, EGR Valve position circuit below self test minimum, & ECT or IAT sensor input out of self test range. I have rechecked the connections on the ECT, MAP & EGR and treated them with Battery Corrosion Guard, which not only protects against corrosion, but helps with many contact problems.
The following lists all I've done over the period of this problem.

April 2009: 184,000 Miles; Replace fuel injectors. Four pintle Bosch. Rebuild LF brake caliper. Pistons were sticky and wore pads out in 36,000 miles. New pads. Need to check idle control valve.
Jan 2009: 183,500 Miles; Replace headlight switch (prior replacement @ 152,000 miles 2001). Replaced distributor cap & rotor. Installed NGK G Power Platinum spark plugs. Left rear spark plug was not white, like others, also looks like gap was too small. Repair port running board. Engine will fire and die, subsequently not firing at all. Replace EGR Control Solenoid. Check MAP sensor connections and silicone grease. Replaced MAP sensor. Replaced coil. Have spark. Resecured engine ground wire (upper). Replaced Fuel Pressure Regulator.
Dec 2008: 183,400 Miles; Greased driveline & steering joints. Changed transmission oil (51,000 miles since prior).
Jan 2007: 177,900 Miles: Checked front wheel bearings. Can go to 200-210,00 miles.
Dec 2006: 177,760 Miles: Greased driveline. Repaired running boards.
Nov 2006: 177,000 Miles; Replaced throttle position sensor. Adjusted resistance to 3240 Ω @ idle, and 322 Ω @ full throttle. Pretty hokey parts and set up.
July 2006: 175,800 Miles; Replaced Fuel Pump and EEC relays. Replaced ignition module (on side of distributor).
May 2005: 172,700 Miles; Replaced temperature sensor (@ thermostat) and EGR sensor (prior replacement @ 166,000 miles).
June 2004: 168,000 Miles; Repaired timing cover gasket blowout. Put O-rings around coolant ports in cover. Put in 5 year anti-freeze. Replaced drive (serpentine) belt.
Jan 2004: 167,000 Miles; Replaced EGR valve & sensor.
Nov 2003: 166,000 Miles: Replace oxygen sensor.
I have also checked a number of items a local professional mechanic recommended.
Whassup?!

 

What is it?

 

1990 F-250, 351W (5.8L), 5 Speed Manual.

 

Could it be the PCM (computer) and where in the world is it?
Rod

 

computer is under the drivers side kick panel. i don't think it's bad, I think you have some really serious vaccume problems. check and replace what's bad, the plastic lines get hard and break over time. if you as much as tune up, you move and break the lines. also check the bottom of your vaccume reserve can, good bet it has rust holes in it and giveing you a vaccume leak you would never think to look for

 

All the vacuum lines are good, but I haven't thought of the reserve can.
Rod

 

Turns out a 3 month old MAP sensor went bad.
Rod

 

Also found the EGR Valve Position Sensor had gone bad for the 3rd time.
Rod

 

sounds like you need to clean all your grounds. you may be getting an electrical spike through these items

 

I hadn't thought of that, but I have cleaned some grounds already, in the trouble shooting process.
Thanks.
Rod

 

Where are you buying these sensors? They seem to have an abnormally high failure rate.

 

Motion Auto Supply: A locally owned eastern Washington parts outfit. the brand was Borg Warner, but has been bought by Standard. I have given feedback to Motion, and they will advise their supplier.
Rod

 

Many here will tell you that when at all possible, go with OEM Motorcraft or the original supplier to motorcraft, even if cost a bit more or are more difficult to find. Many suppliers have it, you just have to ask. The two major Ford OEM sponsors here are great sources too.

 

After all the trouble I've had with Motorcraft parts on this truck (I've owned it for 16 years, and my Dad bought it new), they are the last ones I prefer to use. Although in retrospect; some of them have lasted well. So I guess I'm between the devil and the deep blue sea! I think this truck was assembled on a Friday before Labor Day weekend (i.e. Lemon).
Rod