Bad miss when cold untill full boost. 2003 7.3 F350

Got a mess of problems out of my dads 03 F350. Truck has 105K miles now, and an old custom burt diablo plug in chip (plugs into ecm like a TS flip switch) that only kicks in between 1200 and 1800rpm. It has a bad miss when you first crank it up and it doesn't matter if you let it sit for 5 minutes or 3hrs warming up it will still miss going down the road when you first take off. To get it to quit missing you have to wind it out fast and hard in 2nd or 3rd gear (6spd). It clears out and runs great after you hit full boost and high RPM for the first time. This has been going on for about a month or 2 now.

For the past 2 years we had a CEL come on when you had a load hook to it. The trouble code was for the Injection pressure too high or too low. Just the other day we changed the Injection Pressure Regulator to see if that might be the reason for the miss, but its still there.

Another problem we have had for the past 2 years is if you let the truck sit long enough with the high idle and the warm up valve kicked in, the warm up valve sticks and will not close for a few miles down the road, truck has no power till the valve closes. Now with dead miss problem and the valve sticking, the truck will miss and cut out the whole entire time and will not have any power no matter how long you drive it. I few of my friends say I need to clean the valve to keep it from sticking, but I have no Idea how to go about cleaning it or where to start to get to it. Any help would be apreciated there.

Fixing that will keep it from missing after you hit full boost, but I'm still puzzled why it misses like crazy untill it hits full boost. Even with the valve stuck open and you wind out the engine to redline, it will still miss unless the valve is closed and the turbo makes full boost. We had a scan tool ran on the truck and it said the number 8 injector was giving us fits, so we know we are gonna have to replace it some time (odd ball AE code injector too), or maybe something else is causing the injector to miss fire. Could this be a map sensor problem? or is it something totally different?

Thanks for any and all help with this.

i wish i could help this is what my 02 7.3 is doing except it wont quite missing until it gets completly warm or if i plug it in it wont do it. But my warm up valve closes when i tap the brake or hit the gas. I need some help also

First check ohm check valve cover gaskets and the under cover wire harness. I have 6-10 trucks per year come in with misfiring and all sorts of bogus codes due to bad injector wiring, also check the ICP sensor, pull the plug and make sure it's dry (no oil) if there is oil replace the sensor.

well, we relaced the ICP regulator and the #8 injector. Everything seemed fine yesterday when we picked the truck up. Dad plugged the truck in last night and drove it work with no problems. Today when he was leaving to go home it was missing like crazy and had no power. He thought the fuel filter maybe clogged so he changed it. When he pulled the filter cap, the canister was only half full of fuel if that. We think the fuel pump might be going bad. He drove it home with a dead miss the whole way and hardly any power. I plugged the truck up and let it sit for about an hr, cranked it up and it ran fine. IDFK what the deal is.

having to rev up to clear the miss was an injector proplem in my stroke.

Well we took it to town this morning. I left it plugged in all night, started it up and let it run for just a minute before we left. It missed for about a half mile gradually clearing out for that first half mile. Before it would clear out comepletly all the sudden once you wound out 2nd or 3rd gear.

Have you called Richie? What about Ryan Bean? I'll txt you a couple of other #'s too. Travis Dykes (MoreMPH) & Michael Paul Jr (Dieselfever78)

My dad had a '99 that did this.. Never figured out the problem for the miss, but I unhooked the EBPV at first then totally removed it later on.. Have had 4 7.3ls that had the EBPV go goofy

Ok, we replaced the driverside injector harness and put a new fuel pump on it.... still does the same thing. I drove it for 30 minutes on I-65 from Bowling Green, every red light I came to that day in town it would miss a little bit on take off, but ran great all the way down the interstate. I got off the exit and as i was driving it it gradually started missing again then had no power at all and would barely pull its self up hill and haising white smoke while it was missing. Still can't figure this out.

BUMP i went to car lot yesterday and drove an 2000 7.3 it did the exact same thing the dealer said that it was just cold and hadnt been started in a week, so im goina go up there again tomarrow and try it again so if you guys find the solution it would help me out alot with any future problems.

Just curious if issues solved? If so, what was the problem? Having this same problem now for the past couple of months. ICP pressure 415 to 540 psi, Duty Cycle 9%. That is in the stock tuning. ICP unhooked, Duty cycle goes up the 12%.