Running Rough below 1500

[pablito]

i I have a newly rebuilt 7.3 that was running great, it started running rough and missing at lower than 1500 rpm and a constant check engine light. I had a spare IDM so I replaced that, and it did not help. I would rather not buy the diagnostics software right now, but without it or a programmer I can't read the codes to diagnose it. Do the symptoms that I am having tell any of you guys what might be wrong with it?

Thanks for any help you can give!

[kanuck15]

hows the fuel pressure?

[Cllake]

Hows your fuel filter?

[kanuck15]

also the fuel pressure regulator screen? seems like a blockage but then again wouldnt it be the other way around? good low end bad high end

[pablito]

The fuel filter has 500 miles on it and I don't have a fuel pressure gauge.