CEL, intermittent misfire, no code. Where to begin?

[309]

So I've got a 1999 7.3 air duct cleaning truck. Works great.

This morning I got what felt like a misfire under light acceleration along with the service engine soon light coming on. Ran it on the job (running pto at 1382 rpm) all day. Sounded fine, light stayed on. Driving away from job misfire seemed less pronounced but light stayed. Went to Napa to use code reader, no code. I've been conditioned to think running issues with no code = bad cps, so I swapped in a new one. No difference.

A couple of trips around the block since changing out the cps has shown that the light is still on, but the misfire is so slight that I feel I may be imagining it.

I'm at a loss for what to even look at now. This truck is my livelihood, so proper running is essential.

Ideas?

[NoRalPh]

The thing is... The equipment NAPA has is just not up to the task. Those generic OBD-II readers are of little use on our trucks because they are Not, strictly, OBD-II (despite the connector )

If your light came ON, there ARE codes, you just need more a sophisticated tool to retrieve it. And that will give you the most accurate direction into finding out what the computer saw as out-of-spec when it happened...

An Independent diesel shop, Ford dealership, of someone with an AutoEnginuity is what you're looking for.

[309]

Originally Posted by NoRalPh

The thing is... The equipment NAPA has is just not up to the task. Those generic OBD-II readers are of little use on our trucks because they are Not, strictly, OBD-II (despite the connector )

That's a good bit of info. I'll start with finding a proper code reader. Thanks for providing direction.

[bob harris]

You might try disconnecting batteries for a few hours which I believe will clear memory in computer, used to work for my Chev K2500 6.5 anyway /

[dencon]

i have a 2001 7.3 with a wide variety of codes, it misses while driving (intermittent),also stalls turning corner sometimes,here are the codes i got from a mech.
P1211,P1217,P1280,P1283,P1284 . i dont know where to start ,these are all injector,pressures, circuits. 215k miles. always been reliable .
Any help would be appreciated.

[309]

Mine turned out to have Idm and injector codes. Turned out to be the uvcwh on one side.

Working great now.