6.9 idi engine light

[Hunter]

I have a 1987 6.9 and the check engine light comeson when idling but soon as you give it throttle the light goes away.any ideas or help would be appreciated!

 

[ToughOldFord]

How's your charging system?

 

[Rot Box]

Check the oil pressure and/or gauge as well. When my gauge drops below a certain amount the light comes on.

 

[tbiagent69]

+1 Rot Box

Previous owner removed the oil sensor to install a mechanical gauge. I guess the lead for the sensor is just hanging because the oil pressure fluctuates rapidly like it's bouncing off the engine or something while it's running. When it drops to 0 PSI (low) the check engine light flickers.

I'd suggest checking your oil pressure sending unit. It is possible you just have no oil pressure at idle.

 

[icanfixall]

What is the engine idle rpm. Might want to up it a 100 rpm if its low. I like an idle around 650 to 750. Others like a low slow idle.

 

[theguruat12]

+1 on the idle rpm. Stock on the 6.9 from my data shows that 650 +- 50 rpm is good, mine idles a bit higher, around 750, like Gary's.