7.3 problems 99

[Akzukman]

My brother has a 99 F-550 powerstroke and friday this last wk the service engine light came on checked the codes and we got a p1316 truck still ran but we went to drop it off at the house till we could find out the problem. Well on the drive back home she started running real rough and hesitating to the point at full throttle she would only get up to 30mph. We tried the under valve cover wiring harness it didnt fix the problem, we tried the cps that didnt change anything, we had a spare computer tried that didnt help replace the box under the drivers fender that didnt help we found a few chafed wires and were swapping out wiring harness from a wrecked truck we have. I unplugged the icp but it didnt change its running habits it still ran rough.
What else do you guys think it could be. She starts easy and if you clear the code she will run good for about 30 seconds and then she starts running like crap again.

 

[yoslick]

I'm sure you checked oil level, whats the fuel filter look like? bowl full ? when was the last oil change? try swapping tanks ?

 

[Akzukman]

oil level good, fuel filter good for good measure we replaced it and its a single tank f550 with a fuel tank by transfer flow

 

[BigRigTech]

Verify all the ignition/battery powers to the IDM with a 2.5amp light - not a multimeter and check the grounds also. Have you tried unplugging one uvc plug at a time to see if any are not working when the engine is running?

 

[Akzukman]

Verify all the ignition/battery powers to the IDM with a 2.5amp light - not a multimeter and check the grounds also. Have you tried unplugging one uvc plug at a time to see if any are not working when the engine is running?

grounds are good and all ignition and battery powers checked out with a 2.5 amp light and i have tried pulling the uvc plug one at a time everything checked out i even swapped a entire wiring harness from a known good truck and swapped everything except the injectors and turbo from a know working truck and i put new glowplugs while i swapped out the underhood wiring harness

 

[BigRigTech]

I wonder if this may be a fuel is being masked by the IDM. Have you checked your lift pump fuel pressure or HUEI pressures? Maybe the IPR or IPR sensor is taking a dump? I bought some gauges and a line from CAT that are good to 6000psi....If memory serves me right the HUEI rail pressure is up to 5000psi or so....I use them to test 3126's, C7's and etc at work...I'm not all that familiar with the 99 and up trucks so I don't know how they are wired.

 

[Akzukman]

found the problem injector #1 failed on the high side which in turn cause the other 3 injectors to go dead so she was running on 4 cylinders replaced injector #1 and she runs like a champ. We also solved the problem of why she was a little sluggish we found a leak in one of the intercooler tubes so we fixed it and replaced the wiring harness with one that wasnt chaffed.