High idle solenoid acting up?

[Drock]

So over the past 3 days when I start the truck in the morning my high idle solenoid keeps shutting off prematurely. It re-engages if I blip the throttle, but I have to do it 3-4 times till the truck is properly warmed. Do I need to just replace it, or does it just need to be cleaned or something?

 

[cpf240]

Maybe the temp sensor for it is bad?

 

[Hasdrubal]

When my temp sensor failed, the cold advance/high idle stayed on.

 

[Drock]

Well I took the dust cover off and blew it out with some compressed air, hit it with some WD40, and cleaned & greased the connections. There was a good bit of dust in it so maybe this will fix it? I'll know tomorrow morning I guess.

 

[Drock]

Well that didn't work. I looked for the temp sensor. But all I saw was some sort of sensor on both heads that seems to have something to do with the glow plugs, are those it? Or is there a single one somewhere else?

 

[85CUCVtom]

The switch is on the passenger side of the motor all the way in the back towards the fire wall. It has two wires coming off it.

 

[Skinny]

I would throw a DVOM or test light on it. If you are getting power and the high idle isn't engaging you know what needs to be done...

 

[joshuak]

The sensor is on the block where lead number 6 is hooked up.



Testing that part of the system is covered in the electrical troubleshooting of TM9-2320-289-34.pdf



Good luck.

 

[Drock]

Oh okay, so what's the one mirrored on the drivers side then? It looks the same, is it something else? Or are these a pair that need to be replaced as such?

 

[joshuak]

Number 6?



Temperature sensor for the glow plug system.

 

[85CUCVtom]

Oh okay, so what's the one mirrored on the drivers side then? It looks the same, is it something else? Or are these a pair that need to be replaced as such?

The sensor on the drivers side is for the glow plugs not the cold advance solenoid as stated above. They don't need to be replaced together, they are two different systems. The cold advance switch is closed when cold and open when hot, I believe it opens at 90 some degrees IIRC

If your motor is dead cold and the ignition is in the ON position you should have power at the wire on the cold advance solenoid period. Get in there with a test light or meter and check. If no power, replace the switch. It's #2 in the picture.

GM part number 14071047, TM9-2320-289-34p, Figure 54

 

[Chaski]

Is your cold advance working?

 

[Drock]

Is your cold advance working?

Yes, that's what makes me think it's the fast idle solenoid and not the temp sensor. But To apply my own good advise I should replace both just because they're 30+ yrs old. It's just hard to get past the sticker shock. I was able to find the solenoid for $98.00 + free shipping, and the sensor for $85.95 + free shipping , both on Ebay. OUCH!! I didn't know they used gold and platinum in the construction of or trucks geeez!!

 

[Chaski]

Just change the solenoid and wait to change the switch until the next time you have the coolant drained for some other reason.

 

[Drock]

Well replaced the solenoid today and it seems to be working much better now. It goes into high idol much easier and stays there now. When I took the old one off all the guts were loose including the male plug coming out of it. Here's the technical name and part number for it if anybody needs one. Ebay $98.00 with free shipping,.. Acdeco, fuel injection idle speed actuator,. #14066255.

 

[Drock]

Well I spoke too soon, I did the exact same thing this morning. Also It seems to be idling a little high and I noticed there's a flat head/nut on the end of the rod. Is this to adjust the idle?

 

[Chaski]

Yes, that is for high idle adjustment. You can jumper a positive to it and adjust it when warm, or just do it first thing in the morning.

 

[Drock]

I just ordered the high idol temp sensor and I figured I'd go ahead and order the temp sensor for the glow plug system as well. But the one I keep finding looks nothing like the one on my motor? The one I have looks just like the sensor for the idle, and the one their showing is long with a completely different plug. Is there a civilian and a military version of these?

 

[cpf240]

I believe it is an updated part, I seem to recall threads here about having to change the connector.

 

[TacticalTruck]

I just put my high idle on a toggle switch next to my glow plug button. It's nice to be able to bump up the idle when jumping another vehicle.