Cant get 7.3 IDI to idle under 900 RPM

[dawgsfan08]

My 89 F-350 7.3 is idleing high. Ive adjusted the screw till throttle wouldn't go back anymore. The fast idle solenoid is also not touching so that too is not the problem. Truck idles smooth, There is small leak on top of fuel filter around heater plug. What should I do to lower my idle? The truck does not smoke. Even if you accelerate hard. So I don't think it needs adjusted but unsure. Any help would be appreciated.

 

[79jasper]

What is the timing set at?

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[dawgsfan08]

I'm unsure. Have never messed with a diesel before. Just got this truck

 

[icanfixall]

Welcome to the forum. Being new to the diesels are you sure you have loosened the correct idle screw? What you need to do is slightly open the throttle lever to reach the correct screw. The throttle shaft has 2 screws for adjustments. One is for wide open and one is for idle.

 

[dawgsfan08]

I loosened one that backed out throttle. If I recall it had a spring on it. Thanks for the welcome btw

 

[Clb]

Bent pedal linkage?
Someone fixed the streached cable to much?

 

[dawgsfan08]

Idk, the throttle on the IP appears to be set as far back as it can possibly go. I can back screw out more and it just won't make contact. Even if throttle is pulled off. It's as if the pump needs some kind of adjustment.

 

[Clb]

Pull the throttle cable off and check the adj. at ip...
Look at the diesel pedal.
Does the cable reach the ball-stud at ip?

 

[dawgsfan08]

I've already pulled cable off. It won't go back any further

 

[Clb]

Interference?
Auto trans linkage?
Vrv valve setting?
Bad ip?

 

[dawgsfan08]

It's a 5 spd manual.

 

[Clb]

Btw
Fill in your sig line with truck specs!
Helps us id your questions as now we know whatcha have!

 

[dawgsfan08]

K I'll fix that. Thanks

 

[Clb]

Only a few things I can think of ..
As above
timing.
Throttle screw.
Bad tach sensor.?
Lean fuel load at idle.

 

[towcat]

just for *****-n-giggles, change out the fuel filter.
one more thing. the max throttle screw is easy to get to. the idle screw......not so easy. you will need to throttle up by hand and then you can see and get to the idle screw.