Ok I have a 7.3L I just changed the injectors, there are no leaks anywhere. Sometimes the truck will idle smooth as silk sometimes it will rock your fillings out of your teeth, could it be the fuel filter? Also I bought a filter for the year and size engine I have but the filter I have on my truck has the petcock built into the bottom and the filter i bought has openings at both ends? Auto parts store says there giving me the right filter what now?

 

The bottom of the filter on your truck will screw off and screw onto the filter they gave you.
Yes, it sounds like you may have some water or dirt in the filter.
Get a can of clean diesel fuel and fill the filter before you install it, could save you an expensive starter.

 

Yes the parts store is giving you the right filter. 3 different filters fit that engine- 86217 is what the store gave you, this is what it came with from ford. It has a bottom piece that you take off and put on a new filter. I'm guessing you don't have this piece. You have on your truck a 86417. this filter eliminates the bottom piece and just gives you a drain. probably the owner before you changed it and still has the bottom piece. The third filter 86617 is the same as 86417 just with a water sensor port. all the filters have a 12 micron rating just depens on your preferance. (i speak carquest filter Numbers thats what i use for a wix # just change 86 to 33)
As for the problem with your truck change the fuel filter if that doesn't work it sounds like there's air gitting in the system. my fuel tank selector when bad and caused air to get in the system if switched it.

 

Interesting that the micron rating for the 7.3 is 12; for my 6.9 ( Wix 33811) it's 6 microns. Weird....

 

ok i found the filter with a built in drain thanks for all the info, but it still runs rough while idling "sometimes" when i'm on the move this baby is smooth as silk

 

give it a good dose of power service. this may help you out by cleaning the fuel system and injectors. You may have an injector getting weak and the higher rpms is making up for the problem at this time. hope this helps you out.

 

Sounds like ip problems , is there any smoke when its rough. What kind of miles on the ip. either your not getting enough fuel to the ip, theres air somewhere,or the ip needs checking

 

I second the Diesel Kleene, run a double dose through it for a couple of tanks of fuel then change the filter again. If it has any crud in the fuel system it will clean it out. You may want to carry a spare filter and a can of fuel to fill the filter with you till you run a couple of tanks of fuel with cleaner in them through it.
If it cuts a bunch of dirt in the tank loose it may stop the filter up.

If after a couple of tanks of Diesel Kleene it is still acting up you may have air intrusion into the fuel system.

 

I’m still having some inconsistencies in the idling, sometimes I can start the engine and she runs nice and smooth, other times she rocks and rolls, in the morning I also noticed that I’m hearing some chattering coming from under the hood during acceleration but most of it goes away after its warmed up, and there is no smoke and anytime,,,sometimes i ready to put a for sale sign in the window and other days i don't know what i would do without my ole ford

 

soobad, when the fast idle is on the timing advance solenoid also has the timing advanced. This can cause the rattling you are hearing.
It is a good idea to not stomp on the throttle and put a big load on the engine with the timing advance solenoid energised. When she is chattering like a power stroke the timing is over advanced.
That is also good thing to know though, when it is warmed up and the advance kicks off the timing is set about as advanced as it can be, so it ought to run pretty good.

 

ok Dave you were just talking Greek to me,,lol, now when i changed out the enjectors i had to lay on my engine to reach the back of the engine could i have damaged something doing this and what do i do to correct the problem that you just wrote about..thanks for all your help , john

 

Also (just for kicks) check your fuel lines from the tank. I found mine on the 93 leaking ever so little at one of the frame clamps. replaced with a fuel hose ( line not available) runs great now.

 

There is a coolant temp switch that advances the timing and kicks in the high idle till the coolant reaches 110 degrees.

This can take a mile or so when the engine is cold.

Untill the engine reaches operating temp, throttle application should be kept to a minimum.

When you were laying on the engine you could have put excess pressure on something. Check all fuel lines and wires in that area for damage.
Most of the wiring is down in the engine valley far enough to protect it except for a few in the IP area.
As far as fuel lines, did you replace all the o rings in the bleed off caps when you did the injector swap?
Also did you inspect the cross over lines between the injectors for cracks?

When I replaced the O rings in my caps I just bought a length of diesel rated fuel line and replaced all the cross over lines at the same time. I also replaced the funky clip clamps with stainless screw clamps. It was only about 40 dollars for parts to do the entire job. I never had air intrusion problems after that.

Do you notice the stuttering being related to how you park the truck?
Front down the hill it don't.
Front up the hill it stutters.

 

i did repace the o rings cause they came with the injectors but i didn't replace the lines and caps i handled them with kid glove but i do know that the lines and caps are original to the engine do you think i could have air intrusion in thos lines and caps with out seeing the wetness of diesel fuel? cause i started getting better mpg after changing the injectors but that when it started idling badly sometimes...you know you guys are the bomb, thaks for all your help

 

The pressure on the return line is very small.
However when the engine is not running the suction on the line from the fuel trying to return to it's lowest level in the fuel tank can draw air into the system through leaks so small that they do not leak fuel.

That is why air intrusion into the fuel system is so hard to find sometimes.

Lots of trucks have problems when the truck is parked facing uphill but not when facing downhill. The only difference is the level of the fuel in the tank in relation to the engine level. The extra couple of feet down to the fuel level in the tank sucks air in the lines where it won't when parked with the engine downhill.

We have all been at the place you are right now at one time or another.
I wish I could point you exactly to the problem, but there are to many places the leak could be. Fortunately fuel line is cheap. Replacing the lines till you find the problem is not a big expense, just a big pain in the rear.