2002 F350 Ext.cab dually rough idle

[etacet7]

Trying to fix a friends Truck with AE scanner that I am not very familiar with.Buzz test checks good,CCT shows imbalance at #8 injector,pulled valve covers #8 has the LL/AE injector and does squirt oil along with all others.Disconnected each injector while running and each one did make it run worse,if anything #1 may have had a slightly less effect on running than the others but barely if any.Truck has 95,000 miles,oil is 15w40 Rotella and looks new,Scanner shows everything is normal other than the #8 injector imbalance.Cold or warm engine does not change. Truck is all stock besides complete 4" exhaust and Tymar open type air filter.Under hard acceleration blows some black exhaust, feels a little rough and sluggish until about 65-70 mph and then feels pretty smooth.Any ideas to try would be appreciated.

 

[BIG JOE]

Welcome to SDD etaca7

Sounds like a fuel related issue, off the top...

Whats the fuel pressure like ?

Any air in the fuel ? Fuel leaks ?

Joe

 

[etacet7]

Thanks, I will check fuel pressure next.

 

[dpantazis]

how much fuel in the tank? make sure more than half full to eliminate sucking air at the pickup. also check the fittings at the pump for sucking air. better yet, look at the wiki for the hutch mod to see up to eliminate the fittings.