What am I missing?

[pont463]

I have a 2002 f250 4x4 175,000 miles. Truck started running rough cold, but after a longer warm up would smoothe out. This got worse and worse. Then it just wouldn't hardly run. I thought it was the CPS, so I replaced that. It seemed to fix it for about 3 miles down the road. Then hardly run again. I made it home, and put scanner on it. 1316. OK I thought the UVCH. So I replace both harnesses, the VC gaskets, and the pigtails. Still no better with the same code. Then I start thinking something else is causing this So i clean the IPR and change out the ICP. I get the same 1316 code. It says #7 injector short to ground, #1,#3,#5,#7 non contributing. But when I ohm them out 1,3,5 are 2.7ohms, and 7 is 2.5ohms. The working side of the motor is all 2.7ohms. A buzz test sounds good, but you can tell a small difference in #7, but the entire bank is shutting down. I tested the harness all the way to the IDM, so after talking with a ford mech. I went ahead and replaced it. Still no fix. Then I started getting a 0605 code. internal rom error PCM. So I ordered one of those too. Just tried it. No difference. Also, I did notice that the tach went out again, and I believe that is a CPS thing, but it still does the same thing it did with other computer.I did replace the CPS again because the first replacement I got was still the black one, so now I have the grey one. But The wierdest thing is that when the scanner is attached and I get the truck to run at all, if I clear the codes in it, it runs perfect for about 5 or 6 seconds then it shuts off one side. It also does that when you first start it. Starts on 8 cylinders, then shuts off one side. What is next? I have checked fuel, oil, everything I can think of. Is there something that i am not seeing?

[RadarRider]

Originally Posted by pont463

I have a 2002 f250 4x4 175,000 miles. Truck started running rough cold, but after a longer warm up would smoothe out. This got worse and worse. Then it just wouldn't hardly run. I thought it was the CPS, so I replaced that. It seemed to fix it for about 3 miles down the road. Then hardly run again. I made it home, and put scanner on it. 1316. OK I thought the UVCH. So I replace both harnesses, the VC gaskets, and the pigtails. Still no better with the same code. Then I start thinking something else is causing this So i clean the IPR and change out the ICP. I get the same 1316 code. It says #7 injector short to ground, #1,#3,#5,#7 non contributing. But when I ohm them out 1,3,5 are 2.7ohms, and 7 is 2.5ohms. The working side of the motor is all 2.7ohms. A buzz test sounds good, but you can tell a small difference in #7, but the entire bank is shutting down. I tested the harness all the way to the IDM, so after talking with a ford mech. I went ahead and replaced it. Still no fix. Then I started getting a 0605 code. internal rom error PCM. So I ordered one of those too. Just tried it. No difference. Also, I did notice that the tach went out again, and I believe that is a CPS thing, but it still does the same thing it did with other computer.I did replace the CPS again because the first replacement I got was still the black one, so now I have the grey one. But The wierdest thing is that when the scanner is attached and I get the truck to run at all, if I clear the codes in it, it runs perfect for about 5 or 6 seconds then it shuts off one side. It also does that when you first start it. Starts on 8 cylinders, then shuts off one side. What is next? I have checked fuel, oil, everything I can think of. Is there something that i am not seeing?

You didn't get any IDM codes from the buzz test?

[RICHARD @ LINE-X OF CV]

DOES IT DO IT IN ALL TUNES OF THE CHIP. TAKE IT OUT AND SEE WHAT HAPPENS. ALSO, USE THE BLACK CPS, THE GREY ONES WILL GIVE YOU A FAKE #8 CODE AT TIMES. I KNOW YOU ARE NOT HAVING THAT PROBLEM NOW, BUT YOU MIGHT. THE BLACK ONE WILL WORK FINE. KEEP THE GREY ONE AS A SPARE.

[chabo]

Originally Posted by pont463

I have a 2002 f250 4x4 175,000 miles. Truck started running rough cold, but after a longer warm up would smoothe out. This got worse and worse. Then it just wouldn't hardly run. I thought it was the CPS, so I replaced that. It seemed to fix it for about 3 miles down the road. Then hardly run again. I made it home, and put scanner on it. 1316. OK I thought the UVCH. So I replace both harnesses, the VC gaskets, and the pigtails. Still no better with the same code. Then I start thinking something else is causing this So i clean the IPR and change out the ICP. I get the same 1316 code. It says #7 injector short to ground, #1,#3,#5,#7 non contributing. But when I ohm them out 1,3,5 are 2.7ohms, and 7 is 2.5ohms. The working side of the motor is all 2.7ohms. A buzz test sounds good, but you can tell a small difference in #7, but the entire bank is shutting down. I tested the harness all the way to the IDM, so after talking with a ford mech. I went ahead and replaced it. Still no fix. Then I started getting a 0605 code. internal rom error PCM. So I ordered one of those too. Just tried it. No difference. Also, I did notice that the tach went out again, and I believe that is a CPS thing, but it still does the same thing it did with other computer.I did replace the CPS again because the first replacement I got was still the black one, so now I have the grey one. But The wierdest thing is that when the scanner is attached and I get the truck to run at all, if I clear the codes in it, it runs perfect for about 5 or 6 seconds then it shuts off one side. It also does that when you first start it. Starts on 8 cylinders, then shuts off one side. What is next? I have checked fuel, oil, everything I can think of. Is there something that i am not seeing?

what did you find to be the problem? I am haveing the same trouble

[pont463]

the problem after lots of time and money ended up being a bad injector.. #7 to be exact..

[jlarsen]

what i was told was one bad injector will cause the whole side to go into limp mode.

[pont463]

yep.. that is what it did.. and the bad part is i spent lots of time and money and more money, changing everything that everyone else said it was to come down to just one injector..