Rough 2002 7.3l

[nhfarmer]

Looking for help! Just redone heads on 7.3L 4 injector cups cracked. Heads totally rebuilt valves, seats, all new cups. Injectors tested one over delivering and was replaced all others in spec. Engine started second try after rebuild smoke cleaned up right away, but would stall every first try at starting, second try would run good but engine light would come on after stall. Started about 8 times drove about 60miles to make sure the heads were bleed. Went to take to dealer to read codes and light would not come on. Next start the engine would start right away but only run smooth for ten seconds then start to hunt. Checked fuel bowl was right full, fuel pump is pumping(new filter). Checked all harness connections and they appear to be good. Sounds like lack of fuel to me but seem to have lots. doesnt matter what I do now I can't get the engine light to come on. Installed new style CPS 1000 miles ago. Can rev the engine up to 2000 and it is smoother but still hunts a little. Any ideas?

[badazzstroker]

i would check and see if you are getting any codes first

[nhfarmer]

Dealer tells me no light no codes

[badazzstroker]

negative your dealer lied to you,you can have no light and still have codes

[bigcountrysg]

Just because your light is not on, doesn't mean that you have no codes. You stated your light was on. So you have codes stored in your computer. Need to pull them to see what the problem is.

I would also check the oil level in the HPOP, it maybe low.

[mschn99]

i know this may sound elemetery....so dont take offence to it......

but are you sure you have CJ (diesel) oil in it.....

and have you checked your oil level??

[nhfarmer]

Ya I know I shouldnt listen to dealer, we have a love/hate relationship as it is. No offense taken, The oil I have in it is spec same brand and viscosity as the last 100,000 miles. The truck runs very similar to when I ran it out of fuel one time. Does any one know the logic behind the fuel pressure pump does it run continous or is it on a pressure cut out. I am a Journeyman Diesel mechanic have been on AG equipment for 20 years, but I have very little experience on diesels run by wire. Ag equipment is just getting into it we are mostly old school diesel. How much is it to buy a GOOD code reader.

[mschn99]

Originally Posted by nhfarmer

Ya I know I shouldnt listen to dealer, we have a love/hate relationship as it is. No offense taken, The oil I have in it is spec same brand and viscosity as the last 100,000 miles. The truck runs very similar to when I ran it out of fuel one time. Does any one know the logic behind the fuel pressure pump does it run continous or is it on a pressure cut out. I am a Journeyman Diesel mechanic have been on AG equipment for 20 years, but I have very little experience on diesels run by wire. Ag equipment is just getting into it we are mostly old school diesel. How much is it to buy a GOOD code reader.

the pump should provide constant pressure any time the truck is running...

I think your on the right path and i would definately test fuel pressure...however there is no easy way to do it. You either need a special connector to connect in line at the pump or you need to build a gauge fitting through ports on the fuel filter housing...

[badazzstroker]

you can get a good code reader for about $200 or 300 there are cheaper ones but they will not read ford codes you can also get a programer that reads codes for $300 or 400 well worth the money on a powerstroke

[nhfarmer]

Found more out about my rough engine, (slow going I have the flu). Found air coming in the fuel to the filter. Removed output of the frame mounted fuel pump and put a clear line on to it. Fuel coming from tank was full of air for about 2 gallons and then ran clear. Fuel tank is right full so there should be no air leak in the tank. Hooked it back up and it ran great for about 60 seconds then started to surge. I also bypassed the power run side of the fuel pump and ran it continuous. It would appear that the air is being reintroduced via the return fuel to the tank and being mixed it the fuel supply at the intake/fuel sender. What issues could cause air to be sent back to the tank in large volumes? What happen if the fuel check valves are faulty at the head?