Cold advance question.

[Mikeandwendy74]

Hi I have right now zero voltage at my cold advance or fast idle solenoid. Could this be a culprit in why the truck blasts white smoke until it warms up? I am going to wire a toggle from the fuse box to both IP terminals but....at what temp should you kill the cold advance? I realize I will have to shut the cold advance off myself with the toggle switch but thats o.k. I thought I read somewhere around 130-135 anyone know?

[moondoggie]

Good Day!

You might want to click on "Quick Links", then "Edit Signature", & let us know what year, model, equipment etc. truck you are talking about. It's handy, because you don't have to remember to do it, it shows up at the bottom of all your posts automatically. :)

I'm gonna guess you're talking about a non-electronically-controlled IP (pre-94). Two things on the IP receive power through a coolant temp switch (on the passenger-side head, towards the back): 1) fast idle solenoid; 2) timing advance on the IP. Yes, either or both not functioning could cause white smoke for a longer-than-normal amount of time.

Is there some reason you don't want to verify the coolant temp switch failure & replace it if needed? That's the simplest fix.

If you're going to wire a dash switch to the two above-listed items, I'm not sure you'd hurt the engine if you just left it on during warm-up (if you warm-up your truck), then switch off when you get in to drive it. If you DON'T warm-up your truck (I won't/don't), just provide power to these two during start-up, then switch off after you start moving. Even if you do like I do & warm-up by driving easy until coolant temp comes up, the increased load of moving the vehicle will clear up the white smoke pretty quick, at least it does on my rigs.

If you still have excessive white smoke after powering these two things, you're timing may be a little retarded. My daughter's 89 (signature) was doing this. I bumped the timing a little advanced (NOT recommended - MUCH better to have it properly timed) & the white smoke went away. It still doesn't have much rattle, so I figure I'm safe - hope so anyway. :o

Blessings!

[gmctd]

The HPCA switch is on the passenger-side head rear, just back of #8 exhaust port - cuts out at around 85~114deg ECT, iirc.

One orange wire and one green wire in the two-pin connector.

Get a spring-loaded toggle switch so you can't forget to turn it off.

[Mikeandwendy74]

I suppose I could get a new coolant switch :) but I'm an electrician and like to wire stuff. This is only a temp fix, This truck is somewhat new to me so I'm picking away at what causes this what causes that until I know it inside and out. Thanks for the help I found the sensor near the firewall it was unplugged I plugged it back in but the truck was already warmed up. I'll check it during the next round of lets git' er runnin :)

p.s.- I would imagine a switch thats regulated by heat for a cold start would ne normally closed until set temp then open up and break the circuit. Yes for this sensor?

[gmctd]

Correctimundo