- Joined
- Dec 17, 2020
- Messages
- 24
- Reaction score
- 3
- Points
- 3
- Location
- Calgary, Alberta, Canada
- Vehicle Year
- 2006
- Make / Model
- Ford Ranger Spt
- Engine Type
- 3.0 V6
- Transmission
- Automatic
- 2WD / 4WD
- 2WD
So, you're saying that, "somewhere", I actually SHOULD have this "anti-diesel" screw on my fuel-injected 2006? I'll have to look again. Couldn't find it before. Also, I'll try your test suggestion, comparing DRIVE to NEUTRAL, etc, and see what happens with RPMS.If Warm engine idle drops to about 500 RPMs when you unplug the IAC valve then IAC Valve is OK, but could use a good cleaning
Just 2 bolts and it comes off
The Anti-diesel screw IS/SETS that 500RPMs you get when you unplug IAC Valve
So you would have to adjust it quite a bit to get 750-800RPMs as the low limit RPMs, that's what the anti-diesel screw adjusts, the low limit RPMs
Back in the old days with carbs there was a problem with warm gasoline engines having "run on" or "dieseling" after you shut off the key
It was caused by hot spots in a cylinder(carbon build up) or hot spark plug tips
When you shut off the key spark stops but if fuel is still present the hot spots can ignite it and engine will continue to "lope along"(run on) and it sounds like a diesel engine, the pinging/knocking sound, so also called dieseling
If you adjusted your idle down lower, throttle plate closed more, then less chance of Dieseling because of restricted air flow
So in the case of fuel injection its an "anti-diesel screw", because it AIN'T an idle screw, lol
Your issue reads like computer may not be seeing "in gear" and "neutral" difference
On a 2006 automatic thats done by the DTR(digital transmission range) sensor on drivers side of transmission
In Park or Neutral warm engine should idle at about 750
In Drive or Reverse, computer should bump up idle to 800
Same if AC is on, computer gets a signal and it opens IAC Valve a bit more
So after engine is warmed up shift to neutral, then to D or R, idle should go UP "in gear", when you shift, if idle drops then computer is not "getting the message"
Also turn Climate control OFF then AC on, same thing should happen if in Park or neutral, idle is bumped up
Just FYI, AC is ALWAYS ON in any vehicle unless climate control is OFF
AC off doesn't turn AC off, lol, it just doesn't cool, but compressor is still ON
I can't use the AC bit because, in my truck, its stuck on DEFROST to the windshield, regardless of where I turn the dial. Turning it to AC (or anything else) doesn't change it at all. I'm told that's a big-cost fix. Just can't do it.