Rough running F350 Turbo Diesel

[dieselman13]

I have a 97 F350 Turbo Diesel. When I start it, it idles rough. At times it will smooth itself out for a minute or two, but then run rough again. I changed fuel filters, air filter, injector oil. Does anybody have any ideas with what is going on?

[dray8165]

How many miles on it? Does it smoke at all? Do you have access to any high end scanners? Is it rough just at idle, or all the way through the RPM range?

Quick checks - unplug the ICP sensor (front of the driver's side head - inner aspect) to see if it smooths out. This will cause the PCM to use a default high pressure rail value to set the IPR (injection pressure regulator)

Check your MAP sensor hose to make sure its not dry-rotted

Clean your Exhaust Back Pressure Sensor and tube


Welcome to guzzle's Exhaust Backpressure Sensor Cleaning Maintenance Web Page

and if that doesn't help - you might try posting in the '97 section as most of us here just have experience with the 99-03 trucks.

[dieselman13]

its got 153,00 miles on it smokes a little blue when first starts but clears out. sometimes it will run ok for about 30 seconds and smokes like a 7.3 should.lol. it runs rough up until 2500 rpms.

[dray8165]

Did you try anything I suggested?

[dieselman13]

i took out and cleaned the sensors. nothing happened when unpluged exept check engine light came on. the valve cover gaskets and wireing harnes were all replaced. i think the idm may be bad just becuase it runs good sometimes. then again i dont know.