Truck is a 2001 F-350, running a Bullydog set at "extreme" mode. ATS turbo shroud, KnN filter, and a FASS fuel system. I just had my #8 injector replaced, and after about 100 miles on it, I still have a relatively loud clacking noise. The truck idles better, than before the replacement, and the power seems to be there. I took the truck back to the shop and they ran some tests. #8 failed the cylinder contibution test, though no codes pop up. They said to run the hell out of it over the weekend and this should get it running normally. Has anyone experienced this before?
Thanks,
Ron W.

 

I had #1 injector replaced a few months back, it kinda ran funny for maybe 30-50 miles till all the air got purged out of the system.
But, I would think 100 miles should have done it....

keep you foot in it with the OD off, and keep the tank kinda full, see what happens.

 

As always with the K&N and a chipped truck, inspect your intake for any signs of dust to be on the safe side.

100 miles is more than enough to purge the air from the rail after an injector change. How can #8 fail the CCT with no codes?

Make sure your engine oil is full and not due for a change, and the fuel filter is clean. Did they install a new or rebuilt injector? Did they install an AD or AE injector? Did they take any perdel readings, or just go off the failed CCT with no codes?

 

If you have the grey CPS it will cause #8 to fail the CCT.

Is your Fass system part of a regulated return? If not then #8 is at the dead end of the fuel rail and fires right after #6 thus not getting enough fuel which causes it to have a noticeable cackle. The only thing you can do for that is to intsall an aftermarket fuel return to open up the dead head fuel rails.

 

who doesnt have a #8 injector fail?Thats why i put a regular injector in my #8 slot!Hey maybe thats why my truck doesnt start?

 

Thanks for the response guys. Okay, the oil was changed a week before, and that is when they scanned the truck. I was have some rough idle, either a power surge or hestitation (hard to tell) when cruising at a constant speed (especially around 40 mph). They got #8 injector to fail intermittenly. They actually wanted to see if #8 would clear itself before replacing it, but it got a little worse so I took it in the following week. They scanned the truck again to make sure that #8 was the only problem. (Should be noted that I have trusted this shop for the past several years and they are really great guys. Stopped me from doing some dinghead things, that would bring them a lot of money but not give me what I am looking for and would be a waste to me). Anyways, it was still #8. They replaced it with a new (I asked) FFOG (?) AE injector. When I took it back, they did a full scan (I was standing there) and the only thing that came up was the CCT fail. Since my original complaints are gone and I have no other driveablity issues they think that #8 hasn't settled in yet. The FASS system isn't hooked into the rails, so it just the normal Ford screw up there. After I run the hell out of the truck they want to check it again. If there is still a problem they will replace the injector again.
Ron W.

 

Just wanted to update. The injector is still loader than the old one, especiaaly at normal engine temps, but the idle is great and plenty of power. The shop scanned the truck again, and everything is good and #8 passed the cyl. contribution test (they ran it at least 5 times). It has been at least 6 years since I had fuel springs put in, so I will by new ones and hopefully that might quite it down. Apparently this injector has longer leads, making it louder.

 

Thanks for the update...

First off.... I dont know what they tell you but an LL injector is SUPPOSE to be quiter then a regular one.

Secondly: If you like your motor PLEASE get rid of that K and N air filter. They are junk for these big diesel motors...

 

I will be getting rid of that KnN filter.