2006 Ranger 3.0L, V6, idles too low.

[Monty in Calgary]

I've encountered a problem where, after the truck warms up, if I sit and idle for a few minutes, the resting idle sits at around 750 RPM, the engine kinda shudders, the engine light flashes, and when I try to accelerate, she won't move more than 5 - 10 K/hr for a bit, until she suddenly gets her revs back and goes normally again, and the flashing engine light eventually disappears. I understand the idle speed is controlled by the PCM, but it seems that the resting idle speed being dictated by the PCM is just a shade too low. I've taken to "two-footing" her, keeping my right foot very lightly on the accelerator and my left foot on the brake, and I keep the revs up over the 750... usually trying to keep it between 800 - 900 RPM. Since I've been doing that, the Shudder/Flashing/Chugging issue hasn't happened, even once when I was in a long lineup for about 20 minutes.

I also get misfire codes from time to time, and I've had that looked at and the Ford Mech says it's basically something I'll have to live with (old engine, 229,000 kms and 2 cylinders slightly down on compression) and to just treat her well and not freak out when the solid engine light comes on. I'm getting to the point where I can ignore that because I detect zero performance issues when it's on solid, and it's ALWAYS the same old misfire codes when I check them. The two issues "may" be related, but they don't seem to be.

So... anyone have any ideas how I might get this idle speed issue corrected, because it presents QUITE a problem for me. Afraid I'll stall at red lights, or be forced to TWO-FOOT for the rest of time. AND... if nobody knows how to fix this (or suggest a reason for it happening) [some sensor problem?] , how about some way I could jury-rig the throttle or the cable to NOT QUITE release 100% of the way. I would just need to have it stay back from "full" release enough to just keep the RPMs 50 - 100 RPM higher once I let off the accelerator, as that's all it seems to require to keep it from happening.

Thanks, in advance, to anyone who might be able to help me out with this. I'd appreciate it.

Monty

 

[Ranger850]

Check the timing?

 

[Ranger850]

Also: https://www.therangerstation.com/forums/index.php?threads/the-ol-zip-tie-throttle-trick.175322/

 

[Monty in Calgary]

Check the timing?

No. I'll check into that.

 

[Monty in Calgary]

Also: https://www.therangerstation.com/forums/index.php?threads/the-ol-zip-tie-throttle-trick.175322/

Would the throttle body release too far if the cable is stretched, and cause it to idle lower? I just assumed the throttle body would hit a hard stop when released. Am I wrong about that?

 

[NIGERIAN RANGER]

Would the throttle body release too far if the cable is stretched, and cause it to idle lower? I just assumed the throttle body would hit a hard stop when released. Am I wrong about that?

Adhere to previous suggestions first by others. Thats what I think

 

[Bgunner]

Idle Air Control Valve or IAC for short. After the engine is warm unplug it and the idle should drop to close to 500 rpm's or potentially stall. If the idle does nothing when unplugged then the IAC is sticking and should be replaced.

 

[Monty in Calgary]

That is definitely worth checking, as soon as I identify it and figure out how to. So, just to be clear, if, after I unplug the IAC, the idle speed DOESN'T drop, then the IAC is suspect, right? If the IAC is working properly, the idle speed SHOULD drop..... yes? Thank you very much.

 

[Bgunner]

That is definitely worth checking, as soon as I identify it and figure out how to. So, just to be clear, if, after I unplug the IAC, the idle speed DOESN'T drop, then the IAC is suspect, right? If the IAC is working properly, the idle speed SHOULD drop..... yes? Thank you very much.

You are correct, when un plugged the idle should drop. If it does not the IAC is sticking and will need to be replaced.

The IAC should be located on the side of the throttle body.