start up 5 second white smoke and idle rpm's

[carlav1410]

Hello All,

My son just got few weeks ago 92 f-250 7.3 ltr none turbo truck.
I new there was a few things wrong with it but also new could be fixed with only 231,000 on it.

I have an 88 7.3 with over 600,000 on it.

I new it needed glow plugs and injectors and other minor parts but bought it anyways for his first truck.

Changed glow plugs and injectors much better running truck now.
In Manual it says for truck yrs and engine idle should be set by emission control label? (label is gown)
I read on here and net it should be around 650? If i set it to 650 it's white smoke for good 10 mins If I set idle up to 800 it only smokes about 5 seconds. Will this hurt the truck set at 800 rpm's?? Or did I miss something on my install of injectors?

Thanks Carl

[NH2112]

I'd set the curb idle at 650-700, and set the fast idle to 850-900 (spec is 875 IIRC.) It sounds like your fast idle either isn't working or wasn't set correctly, but the procedure takes maybe 2 minutes tops and should be easy to find using the search function. All you'll need is a 1/4" wrench and a jumper wire.

[carlav1410]

Thanks for the reply and i will check that when my son gets home.

also does it matter if engine is cold or hot when checking the fast idle control?

Thanks Carl

[NH2112]

If the engine is hot you'll have to use a jumper from B+ to energize the fast idle solenoid, because when coolant temp is above 115F the coolant temp switch is open and the solenoid isn't energized.

[leyrret]

Installing new injectors usually results in retarded timing, hence the white smoke when cold. This is due to unburned diesel out exhaust which clears up as engine warms up. Speeding up idle likely advances it slightly speeding up the process.