96 F-250 with 7.5l fuel injected and E4OD automatic dies when giving it gas. When I'm in gear at a stop light and take my foot off the brake to press throttle it dies. I can save it sometimes by feathering throttle but usually results in wheelspin which upsets the Prius driver behind me. When it dies, it is like someone turned off the key. It does not bog down. I can pump brakes and it does not change result. When it dies, it is fairly immediate. It doesn't die every time, sometimes it just stumbles, like a "miss". So far, I have repaired a few vacuum leaks from the little plastic tubes. Hooked up the PCV valve (it was disconnected-but it ran good) I have replaced the fuel filter, MLPS Manual lever position sensor and the IACV Idle air control valve. I tested the Throttle position sensor with ohmmeter.

 

Ford Fuel Injection » Idle Air Bypass (IAB) Click on this link and maybe clean the one on your truck.
Also if you click on "Self Test" from the list on the right of that site page you could check for any trouble codes (worth doing even if no light on).

 

I tested with ohmeter, within specs. I read voltage to IAB, within specs. Even went so far as to replace it in case it was damaged mechanically, no improvement. Still dies. Thanks.

 

Then I think I would check for trouble codes and also possibly check the fuel pressure.

 

No codes present on Key On Engine Off. No Check eng light ever came on. Any idea what correct fuel pressure should be or have a link to a good procedure. My Haynes manual isn't that thourough. Thanks.

 

do you have dual tanks ? does it happen on both tanks ?
same problem happened to my 89, i had a bad pump

 

It does have dual tanks. Forward tank pump is suspect (chugs) so I use rear only. I was thinking maybe the rear tank is starting to go bad so I will test fuel pressure when I get a chance. Really didn't want to replace both tank pumps, but I guess if the bed comes off...should only come off once.

 

I checked it with it running off the "bad" front fuel pump. Still dies. Discovered this morning that even if i roll up to a stop in nuetral, the idle is so low that it'll die. So now i know the idle is low and it doesn't even have to be in gear. hmmm... Like i said before, I have already replaced the IACV or IAB as it was called. Now i gotta figure out what controls it.

 

I forgot to mention that this started happening after i disconnected the PSOM (speedo head) in an effort to access the top of the steering column. I tightened the shifter mechanism. I put the gauges back in after realizing i didn't have any better access, and now the speedometer jumps 10-20 mph when driving 40mph. i don't know if it was a cooincidence, but that's when the truck started dying at stops. I have since removed and reinstalled the gauges a couple of times to make sure all the wiring is not obviously broken or disconnected. I have looked for loose grounds etc... And I have replaced the parts listed above. I have searched for vacuum leaks. I am going to replace plugs, cap and rotor so i can rule those out, but am at a loss otherwise...

 

Excuse my bump...I replaced the spark plugs, cap and rotor. No change. I now notice that upon startup, it does not go into a high idle mode. It just hovers at about 600rpm. The idle does increase to almost 1000rpms when i shift into reverse or drive, but after a couple of seconds it just dies. I love this truck, but I am boggled. Surely someone has had this happen or heard of it...right?

 

I replaced the speedometer and fixed this problem.

 

wow...that's really odd.

 

Sorry to bring this back from the dead.

@jimbo285 ...Did you replace the entire PSOM board? Just the actual speedometer actuator?