[OIIIIIIIO]

Hi

96 F250 7.3L diesel automatic 4x4 crew cab short box...

Very rough idle at start up...sometimes it catches up with itself and runs smooth...sometimes doesn't...when it doesn't, CEL comes on...only code I found was P0603 KAM (keep alive memory) which I believe means either the battery way disconnected recently or a chip was in it...neither being the case (tom my knowledge anyway...recently purchased truck).

When driven with CEL it lacks power, barely getting up to 25-30 mph and taking forever to do so...

This morning, turned over, acted like it was going to start but didn't...

Any idea of what I'm looking at?

Have been told sometimes the wiring to the injectors coming loose...and those happen to be under the valve cover?

Any input?

Thanks!
Patrick

 

[ridiculously_necessary]

unplug your ICP sensor. try starting see what happens.

if that doesnt work, pull our batteries and get them load tested. i had a similar problem last year. one battery that was less than a year old had a dead cell and was wreaking havoc on starts. when tested with a meter they were fine. the problem ONLY showed up with a load. my amps would drop from 14.x to 9.x. a meter wotn draw a load.

could also be a fuel repssure issue, etc. but start there. if you ahve a fuel pressure gauge then hook it up to the bowl.

 

[rolsmojave3]

Under valve cover wire harness and valve covers I would guess. If you get these from Napa they come with the engine harness pigtail and valve cover to injector/glowplugs harness.
https://www.napaonline.com/Catalog/...9001+101996+50028+2028036&Ar=AND(P_RecType:A)

 

[OIIIIIIIO]

found a scanner...

p0603...KAM...from what I read/understand...shouldn't have an impact on my problems...

p0344...CPS...this code wasn't on there Mon when I had issues with the rough start and poor idle and lack of power...only showed up after it decided not to start...and from what I've read this code could be tripped by excessive cranking...any way to confirm a bad CPS rather than just throwing a part at it?

thanks!
patrick

 

[rolsmojave3]

My truck just had both of those codes I also had a MAP sensor code, it was indeed the valve cover gaskets/harness. It gets shorted out and the computer gets strange ideas. I replace gaskets, been fine since

 

[elrojo63]

If your tach doesn't move when cranking then your cps is bad

 

[OIIIIIIIO]

my tach does move...would that push me away from a CMP and toward the harness to/in the valve cover?

 

[rolsmojave3]

Well its quite simple to pull the valve covers and inspect the wiring. All I usually do is take off the oil fill cap and smell in there. It usually smells like burnt electrical if you melted a gasket. However a drivers side burnt harness might not smell on the passenger side.

 

[OIIIIIIIO]

finally able to look...as stated several times already...harness in the valve cover is toast...could be smelled quite easily just by removing oil filler cap...

now my question becomes what causes this to happen and if I merely replace the harness, will the get hot and melt again, or is there usually some underlying cause (glow plug issues or something) that i need to address to try to prevent this from happening again?

Thanks!!!

 

[rolsmojave3]

I always replace the GP's when I do the harness/gasket if their condition is unknown. They GP lead off the harness' can also get rubbed through by the pushrod/rocker arm if it's routed incorrectly.

 

[SteelWheel]

I have been told it is due to glow plugs going bad. Mine did the exact same thing as yours last week. After looking around I found the plug on the outside of the valve cover was melted. I talked to a couple of techs they all said if one side is burnt up the other is probley burnt or not far behind just replace both sides. I found a kit on Orielly's Auto Parts site that comes with gaskets inside harness and the outside pigtail for 64.99 per side. Did the job my self in about 3 hrs, hardest part was getting to the bolt on the back of the passanger valve cover, other than that it was a breeze

 

[UNDERCOVER_73]

Sounds like my issue, But im now having Injector problems i belive. anyways.

UVCH is def your prob.

Replace it with a known source. i got both sides, all for connectors, all four pigtails, for 120 on ebay. I paid 30 tohave it next day shipped.