Cold Idle question?

[hayisforhorses]

Cold weather is starting in my neck of the wood and the old rig I am just getting aquainted with only idles at 450 to 500 when she starts, this seems too low, I have read post about cold idle relay and cold timing advance solenoids, where are they at and how to test them? any other suggestions thank in advance!!

 

[hayisforhorses]

anyone?????

 

[fuzzy1626]

On/in the injection pump. To set the fast idle and timing advance, you should depress the accelerator at least half way down and release slowly while the wait to start light is on. If it's working that should set your idle to 900+/- and advance the timing.

 

[sootman73]

Yea the solenoids dont usually work unless you step on the peddle to engage them. but then they stay on. i put my timing advance on a switch on my dash but left my high idle for now. it will be the same too eventually.

your idle is set to low however for any temp. on the arm for the throttle at the pump there is little screw the arm sets against at idle. should turn that a bit so the engine idles at or around 650 rpm.

 

[hayisforhorses]

the temp gauge never moves does the sender unit from the temp gauge tell the cold idle and timing advance soleniod when to engage?

 

[Agnem]

No. They are not related. Your temp sender is probably shot. As for the low idle, if it idles OK when warm then most likely your pump is gunked up. Try running a fuel additive all the time, if you don't currently.

 

[hayisforhorses]

idle is 450 to 500 cold and hot she has been sitting for 4 years when i bought her and she is not quite road worthy yet she starts fine just low idle and runs great have run her up t0 1800 for 2 hours and never missed a beat. sighoned old fuel out looked ok and added new fuel with a double dose of power service diesel kleen starts great once glow plug isse was fixed (motorcraft zd-9) just idles low cold or warm. just trying to get ahead of cold weather issues. replaced all brake lines and serviced all fluids this weekend getting new cherry bomb exhaust{cheap) and new shocks then need tires (on order} then some type of body for a flat bed then she is road ready. My daily driver 99 cummins 24v'r 4x4 need a couple weeks downtime for repairs so trying to get my new old rig ready and no opetion for plug in at work so I am a little concerned about the idle issue and timing advance anyinfo on checking the relays

 

[Fishin76]

when its the engine is cold, disconnect the GP's (to prevent any burnout), Key in the on position, leaning over the engine, disconnect the cold advance solenoid wire and just touch the connector to the spade on it, you may see a spark, no problem, be listening for a click. If you hear a click, keep touching it for a minute in 1 to 2 second intervals to exercise the solenoid. if it is binding, the click will get louder as the solenoid travel loosens up. Do the same for the cold idle solenoid, until it seems to move good. you could also spray the linkage with a little wd40, or your favorite spray lube. I also used this trick to free up a sticking FSS.

I did this to mine, and now i don't even have to push the pedal down for the high idle and advance to work when starting, and when warmed up, you can tell instantly when they shut off.

 

[hayisforhorses]

thanks for the info no worries on the glow plug run a bypass on it. got a diagram so I know which relay is which?

 

[Fishin76]

No, but the one on the very top of the IP closest to the radiator is the FSS, the one behind it is the cold advance. The Cold idle solenoid is on the Passenger side of the IP, where the throttle linkage is.

 

[Agnem]

Another way to test the cold idle advance is to disconnect the fuel return from the IP. With the cold idle advance actuated, there will be a generous amount of fuel flowing. With it off, there will not be as much. An easy and more complete test than just listening. Naturally you have to be feeding fuel to the pump. Easy to do if you have an electric fuel pump. If not, you'll have to do it with the engine running.