It has been really cold here in Wisconsin and I don't think my fast idle is working during warmup. How do I check it, diagnose that it is working. It is only at 750 rpm or so when it warms up. Thanks in advance for the help.

Check the fast idle solenoid for power when the motor is cold key on engine off.
If no power check temp sensor on the thermostat cross over for power on both wires when plugged in key on Eng. off.

Will do. I'll report back what I find. What if no power at the thermostat cross over?

IIRC, its tied to the Ign wire of the IP, so if it will run you will have power atleast on one of the two terminals.

Another trick you can do is, jumper across the two terminals of the temp switch connector, crank the truck, unplug the jumper see if it idles down and quiets down.

What if no power at the thermostat cross over?


Perform an exorcism!:D

well how did the diagnosis go?


What part of Wisconsin you from faciszewski ??

Marshfield, WI
Going to do the diagnostics tonite. I am also going to do the water bucket test for the CDR which I think needs replacing as oil consumption is going up. Thanks for all the help. Awesome site.

ok. I do have power at one terminal of the temp switch with ign on, engine off. If I jumper the temp switch after the engine is running the idle does not change. Now what?

I did the hose on the dipstick tube check and it pulls a negative pressure up to one inch of water. So, CDR ok.? So I wonder why I am using 1 quart + every 1500 miles? Thanks again for the help.

So I wonder why I am using 1 quart + every 1500 miles?

Time for a compression check. Rings or valve guides (or a leak).
Good news - IT'S NOT YOUR PMD :)

ok. I do have power at one terminal of the temp switch with ign on, engine off. If I jumper the temp switch after the engine is running the idle does not change. Now what?



Complete the test.
Did you have power on both terminals?
When you jumped the switch did you have power at the idle solenoid?

Also keep in mind the solenoid will not push the throttle open.
You need power there first, then when you open the throttle the plunger will extend to prevent the throttle from returning to the previous opening thus your fast idle is now working until the solenoid powers down.

Completed. Awesome explanation. Now I understand it. If I jump the connector and open the throttle it bumps up the idle. I just need to adjust it now. What RPM should warm up be?

Help on the oil consumption part? 1.5 quarts in 1500 or so miles. CDR test was fine- 1 inch of negative vacuum. No blow by. Excellent power, towing ability etc. A little leak, very little at rear main and valve covers.

I have some blow by (not enough yet Louis!):p: but I may hit the add mark by the oil change time. It may be that your oil leaks are worse than you think.

I'm thinking 1,100 but can't be sure off hand.
Should be a lable under the hood for idle speed settings.

Ok. I went to Advance to get a new temp sensor switch and the one they said was for my truck didn't look like it at all. Where can I get one and what is the part number? I did look in the parts section sticky, but that part not listed.

Dealer has it listed as a Coolant Fast Idle Switch;)

Super. I will call them tomorrow. Thanks again!