IDI Fast Idle Mod.- is it worth it?

[tbrumm]

I have been considering doing the fast idle mod and installing the switch and diode to manually control the fast idle solenoid. My reasons for possibly doing this are:1.) Make a little more heat for the interior (its darn cold here sometimes!) by keeping the rpms up while "idleing", and 2)minimize the possibility of "wet stacking" from extended low rpm idle. So, normal idle is around 650 rpm, and my fast idle solenoid is currently set at about 950 rpm. Does anybody know - is this 300 rpm bump enough to prevent "wet stacking" in our engines, or is that just wishful thinking on my part? I would probably only make use of the manual fast idle control during the winter, as it would be nice to be able to leave the truck idle a little longer when it is so cold. But, leaving it low idle longer doesn't really help much to build cab heat either. Just wondering how beneficial you guys think this mod might be. Anybody do the mod and are you happy with it? Thanks for your input. Todd

 

[Kevin 007]

Yes it is worth it because it is just so simple to do. My biggest reason for doing it is because that factory set up kept it on fast idle for too long for my liking after a cold start. Now, I have mine fast idling for maybe 2 mins at the most, then I switch it off. Fuel aint cheap and I try to miser as much as I can and this is just another way of doing that.

As for wet stacking, 950 should be enough to prevent it. Another benifit to the mod is that you can boost your revs manualy for events such as jump starting, running heavy electrical loads while truck is just sitting there, etc...


My fast idle is at about 800rpm. The reason I don't have it as hight as some is because I really don't want the revs any higher with a bone cold engine.

 

[1466IH]

I dont use the high idle much for could starts because i have it set too high. Mine is set around 2100rpms because i have an under hood air compressor. Iwist there was a cheap and easy way to put my high idle back where it should be and have another throttle control for the compressor

 

[G. Mann]

OK... someone who has done this mod please "splain" how it's done. I have no fast idle working on my truck. I want one.

Apparently the temp switch or the fast idle kicker is not responding, never have been able to get it sorted.

To 1466TH, have you thought about using a simple Boden cable to run throttle for using the compressor? A hand throttle cable like on a lawn mower? Just put a small chain link at the throttle end so your foot feed works normal. When you are parked and want compressor speed, pull the cable to the RPM you want. Might have to find one that has a twist lock feature, so when you get rpm set you twist the knob to lock it.

Just a thought.

 

[tbrumm]

The write up for the fast idle mod is in the IDI tech articles. Kook for "High Idle Solenoid Manual Control". on page 3. It seems to be a really easy mod to do. I was just wondering if the fast idle was really fast enough to eliminate the wet stacking problem from extended periods of low idle.

 

['94IDITurbo7.3]

wet stacking? is that fuel collecting in the cylinders?

 

[tbrumm]

wet stacking? is that fuel collecting in the cylinders?

Yep. From what I understand, our diesels don't completely burn the fuel shot at low idle. So the unburned fuel can make its way down the cylinder walls washing off the lubricating oil and can gum up the ring packs. I try not to allow my truck to idle any longer than absolutely necessary, but when its so cold, you gotta get her warmed up a bit!

 

[Greg5OH]

hmm im going to look into this. In the winter i dont like to shut her off even if i have to run in for 15 mins, a manual high idle would be great as im always concerned with cylinder wash down. My normal high idle works fine.

 

[Matrix37495]

I dont use the high idle much for could starts because i have it set too high. Mine is set around 2100rpms because i have an under hood air compressor. Iwist there was a cheap and easy way to put my high idle back where it should be and have another throttle control for the compressor

How the heck did you get it that high while not bothering the low idle? I'd like mine a little higher for my air compressor, but i was thinking 1500....

 

[Greg5OH]

im really jelous of your lights matrix

 

[79jasper]

I didn't want to spurt out anything, because I haven't done any testing yet. But we have plenty of actuators available to make a better high idle solenoid.
Numero uno: idle air control valve from a gasser. Usually have four wires, can also be setup to be adjustable from in cab.
Die zwei: a door lock actuator. Would give a good size jump in idle, but non adjustable.

Plenty of other stepper type motors to be used.
Just gotta know your electrical components.

 

[Wyreth]

I didn't want to spurt out anything, because I haven't done any testing yet. But we have plenty of actuators available to make a better high idle solenoid.
Numero uno: idle air control valve from a gasser. Usually have four wires, can also be setup to be adjustable from in cab.
Die zwei: a door lock actuator. Would give a good size jump in idle, but non adjustable.

Plenty of other stepper type motors to be used.
Just gotta know your electrical components.

There's also the idea of using a manual kick. on the cheap and simple, a manual choke cable and a slide linkage from a kickdown would do the trick easy. Altho that would be better for a hydro, weldernator, or onboard air throttle kick.

 

[79jasper]

Wyreth, exactly man. Way simple ways of doing stuff. I don't know what they call them, but the twist cable with the red release button in the middle would be perfect.
What'd be cool is something referenced to said accessory, lets say an air comp, so that once a preset pressure is reached, it'll kick down to normal idle. Then when the pressure drops, it'll kick back up.

 

[LCAM-01XA]

I dont use the high idle much for could starts because i have it set too high. Mine is set around 2100rpms because i have an under hood air compressor. Iwist there was a cheap and easy way to put my high idle back where it should be and have another throttle control for the compressor

OMG, what kind of compressor needs that high engine speed? I got the "big" York and I hardly ever run it at engine speed over 1000 rpms, ideally I'd run it at idle but the belts flop around a bit too much for my liking and w/ two air tanks it takes longer to get up to pressure than I got the patience to wait for. As for the easy idle adjust, read below.

Wyreth, exactly man. Way simple ways of doing stuff. I don't know what they call them, but the twist cable with the red release button in the middle would be perfect.

It's called a vernier cable, and IMHO it's worth its weight in gold. I use mine every time I run the OBA, also when jump-starting, and on very rare occasions as a form of cruise control. You can run a short cable to just the throttle pedal, or a full-length cable to the IP lever itself - short cable saves on engine bay mess, long cable can get you home if you happen to snap the factory throttle cable - take your pick.

 

[79jasper]

I haven't bought them before, but this looks like one helluva deal -> http://www.amazon.com/gp/aw/d/B002ET2O2W