High idle in park and nuetral? Help?

[DREWSDIME]

I have an 85 720 with auto trans and just recently it started having a high idle when I put it in park or nuetral. Could this possibly be vacuum lines? I Just pick up some braided vacuum line today ($2 a foot) looks like it will last alot longer than just normal rubber lines, I will install new lines tomorrow after work and hopefully this helps

[datzenmike]

When thoroughly warmed up take the top off your air filter and check that the choke isn't on.

 

 

This is usually a charging problem. Is your battery staying charged? Is the charge light on? Is there a buzzing sound from the glove box area?

[DREWSDIME]

My battery is fairly new and is staying charged. Charge light is not on. I did start to notice a slight sound this week sound more like a humming possibly buzzing coming from passenger side somewhere but it sounds like its coming from engine compartment, Im not positivie because my ears are all plugged up from my allergies and cold this week so its hard to tell exactly where its coming from. The sensor light did start to come on recently only when I first start the truck but as soon as I rev the engine it goes away. When truck is warmed up and I take off the top of the air cleaner to check the choke, will I just notice the choke stuck open?

[datzenmike]

What happens is the alternator has to be charging for the choke heater relay to be on. Whith the choke heater on the choke warms up and turns off. This is how it's supposed to work normally.

 

If there is a charge problem the relay will often buzz and not operate properly, the choke doesn't warm up and turn off. If the choke is on slightly the fast idle may be on..

[DREWSDIME]

I see, I will check this out tomorrow after work. Thank you