missing at high rpms

[kspence101]

2000 F450 7.3 AUTOMATIC,TRUCK FALLS ON ITS FACE WHEN REALLY MASHING ON THE THROTTLE,OR RIGHT BEFORE IT SHIFTS,YOU CAN LET OUT OF IT AND IT CLEARS UP BUT STARTS AGAIN WHEN ROUND 2200 RPMS,JUST CHANGED OIL AND IT STARTED COUPLE DAYS LATER,NO SES LIGHT ON...SEEMS TO DO IT THE WORST WHEN YOU REALLY CROWD IT KINDA LIKE NOTHING IS FIRING UNTIL YOU LET IT GO BACK TO IDLE.....HOPE SOMEONE CAN HELP.......THANKS IN ADVANCE KEVIN

[TurboSevenThree]

definately sounds like some missing is goin on, not sure though. JUST curious, does it stumble less when you turn the overdrive off or no?

[kspence101]

HAVENT TRIED TURNING OVERDRIVE OFF BUT I SURE WILL......BUT IT SEEMS TO JUST DO WHEN RPMS GET HIGH UNLESS YOU BABY IT BUT EVEN THEN IT WILL BOG DOWN AROUN 65 TO 70 MPH AND WHEN IT STARTS YOU HAVE TO LET OUT OF IT TO CLEAR IT UP.......THANKS IN ADVANCE HEADED TO TRY OVERDRIVE BUTTON

[TurboSevenThree]

Oh it might make it worse then, although i really don't know.

I had a wiring harness loose under the valve cover on one side (my fault) and it was missing on FOUR cylinders! It stumbled bad but more in lower rpms like 1300 it would SHAKE like no tomorrow!! and turning the overdrive off helped it stumble less to get it home easier, otherwise i would have to raise the rpms up then let off (that shuts the injectors off so it literally coasts for a bit) so it wouldn't shake so much. Lopey lopey idle, the turbo sounded like it was half not there, could only hit 7psi MAX. It was bad.

[TurboSevenThree]

Are you getting semi-adequate boost? (not totally if it's missing obviously but...)

[kspence101]

OK OD BUTTON DOESNT SEEM TO MATTER.WHEN I NORMALLY MASH THE PEDAL IT WILL DO GREATT UNTIL 60 65 MPH THEN BOGS DOWN ON IT FACE UNTIL YOU LET OFF.OR IF YOU REALL ROMP ON IT FROM A TAKE OFF IT WILL CHOKE DOWN ,YOU JUST HAVE TO BARELY ACCELERATE TO GET IT TO TAKE THE DIESEL AMD LET IT SHIFT WITHOUT CROWDING IT HOPE SOMEONE HAS HAD A PROBLEM LIKE IT BEFORE,,,,,,,,,CHANGED FUEL,AIR .OIL ALREADY..........HAVE PUT UNDER VC HARNESS ON PASS. SIDE BUT IT WOULD SKIP AT IDLE .......THIS TIME IT 2200 UNLESS YOU JUST HAMMER ON IT..

[TurboSevenThree]

Hm I don't know then. I know you can run it without the heads for a short time. So if you can't get it hooked to a scan tool you can unplug the injectors one by one and see which one makes it run worse, and those are your good ones.

Hope ya get it figured out bud!!

[kspence101]

WELL GUESS I WILL PULL VC TONITE ALSO HAVE NO CRUISE CONTROL.HORN NOT WORKING RELAY CLICKING,TEMP GAUGE STAYS ON COLD I REPLACED SENDING UNIT ON THE WATER NECK STILL NO TEMP.HMMMMMMM JUST MY LUCK DAY THANK FOR YOU RESPONSES.......GREAT SITE

[kspence101]

update ................took it to the dealer pulled codes p1211,p1247,p1282 ..........if any techs could help man i would really owe ya one.......

[kspence101]

still havent figured it out,,,,,,,,,really does it when pulling a hill like eratic missfire........stumped