Need IDI help! (Gary,Brian,type4) chime in!

[larson]

For all you long time owners of idi powered vehicles.
On an n/a 7.3 210,000 miles never been torn into engine with original injectors, ip with 60k on it.
It has a nice knocking sound on a cold start up that gets quieter with temp coming up but doesn't go away. It does go away with rpm.
The only issues I have noticed latley is driving at 70mph with a full tank of fuel it will some times cut out like its getting air in the lines especially when I let off the throttle all the way.
Any ideas on both of these situations?
None of my return line caps are leaking. The only thing she leaks is oil. I still get 18mpg average.

 

[gandalf]

210000 miles is a lot for original injectors. Way too much. They have served you well, but I think it's time to retire them and replace with new. Old injectors will cause a knock. Now wait for others to reply.

 

[BrianX128]

Bad injector? Try cracking them one at a time yet to see if the sound goes away with one?

 

[Thewespaul]

Guess since I’m not on your list I can’t answer

Even tho blatant injector problem

 

[larson]

Someone buy me some new injectors lol!

 

[hoodshauler]

No question you need injectors


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[riotwarrior]

Sounds like worn injector/s and IP...air could be getting in though too for power loss...flex line to lift pump at time cracks...and there are several olives on hard lines that over time become work hardened and brittle...air is smaller molecule than fuel...so may leak only 1 way...

JM7.3CW Eh!

 

[IDIoit]

I have a box of 6.0 injectors you can have if you come pick em up

 

[jwalterus]

I have a box of 6.0 injectors you can have if you come pick em up

Heck, if you can make them fit and work in an IDI, I'LL make the drive!

 

[icanfixall]

Well as already posted. The knock is an injector that opens so early that it causes a fuel knock.As for the rev and stall my guess is you have not run any fuel treatment and the pump internals are sticking. Time for injectors and start running a fuel treatment but double the dose in a tank of fuel so it cleans the injection pump.

 

[OLDBULL8]

I have a very different opinion than the others.

For all you long time owners of idi powered vehicles.
On an n/a 7.3 210,000 miles never been torn into engine with original injectors, ip with 60k on it.
With only 60K on the IP I surely don't think you would need to replace the IP. If your getting 18 MPG that goes for the injectors also.

It has a nice knocking sound on a cold start up that gets quieter with temp coming up but doesn't go away. It does go away with rpm.
That is normal when starting a Cold engine, when the knock goes away when warming up, that tells me the timing is set close to perfect, specially when getting that kind of MPG.

The only issues I have noticed latley is driving at 70mph with a full tank of fuel it will some times cut out like its getting air in the lines especially when I let off the throttle all the way.
It could be the IP metering valve is sticking at times when you let Off the throttle, as far as stumbling at 70 MPH, almost WOT, could be lift pump is not keeping up with needed fuel or air intrusion
Any ideas on both of these situations?
Empty your fuel filter, then fill it up thru the outer ring of holes with SeaFoam, run the the engine at idle for 4-5 minutes, shut it Off and let it set for as long as you can, overnite would be sufficient. See how it acts then. SeaFoam, $7.50 a can.
None of my return line caps are leaking. The only thing she leaks is oil. I still get 18mpg average.

 

[FORDF250HDXLT]

Yeah,I'm with Bill.An injector "knock" sounds god awful.To the normal person,it would scare the crap out of them as they might think it's a rod knock.
Also,injector knock doesn't go away when the engine warms up.I too think he's just describing timing advance and not an engine knock of any kind.

If your driving 70MPH and averaging 18MPG........Don't touch a damn thing!

 

[hesutton]

Smoking more than normal? Rougher idle? Injector knock (for me at least) has always been associated with more fuel smoke, rough uneven idle (a miss), and I can't hear it at all when not at idle. Also, common to have a very hot injection line and melted return cap. Often the failing injector will let combustion gas leak past the nozzle and into the injector body, thus hot line and melted cap.

Heath

 

[larson]

Smoking more than normal? Rougher idle? Injector knock (for me at least) has always been associated with more fuel smoke, rough uneven idle (a miss), and I can't hear it at all when not at idle. Also, common to have a very hot injection line and melted return cap. Often the failing injector will let combustion gas leak past the nozzle and into the injector body, thus hot line and melted cap.

Heath

Well it does idle like a gas motor with a mild cam and solid motor mounts. You can definitely feel the (miss so to speak)

 

[larson]

Yeah,I'm with Bill.An injector "knock" sounds god awful.To the normal person,it would scare the crap out of them as they might think it's a rod knock.
Also,injector knock doesn't go away when the engine warms up.I too think he's just describing timing advance and not an engine knock of any kind.

If your driving 70MPH and averaging 18MPG........Don't touch a damn thing!

It is god awful. It sounds like the piston isn'teven there and the connecting rod is just slapping the cylinder wall.