Fast idle not engaging randomly when cold

[irowiki]

This is the first tercel with everything "on" the carb. The fast idle is random when she is cold. The first day we had her, I started her up when cold and the fast idle kicked in and took her up to 2000-2500 rpm. Since then, it is random, sometimes fast idle will kick in when she isn't so cold!

This morning it was 35 degrees, gave her two gas pedal pushes, she fired right up, then the idle started bouncing off near stall (800-1000), so I had to manually hold the idle at 2000 for a bit. I see in the FSM how to adjust the fast idle, is this is what I'm looking for, or is there another issue?

[Jarf]

Most likely culprit is sticky choke plate/linkage.
Start with making sure everything is free and retest.
I would resist the temptation to "adjust" anything until you have ruled out all other possibilities.

[dlb]

i had a similar experience with my last project terc and the culprit were broken diaphragms in the choke breaker. just put a clean hose on them and suck. you should not be able to suck air through. if you can suck air through, you can replace them. i posted how i did this a while back.

https://tercel4wd.com/forums/viewtopic.php? ... =30#p63661

[irowiki]

Ah ha, may or may not be related, but I think the AAP is bad.

On cold starts, there's a strong gas smell, runs fairly rough, and when I had to give it a good bit of gas out of a stop sign on a hill, there was a large hesitation. All such issues go away when she warms up.

Now if I could just find the diaphragm instead of buying another rebuild kit!

[dlb]

if u or anyone near u has a parts carb, u could pull the aap off of it. i've done that. it's easy to remove and obvious if it's broken.

[irowiki]

I checked, no fuel in the vac line and it held vacuum. New thread time!

[marlinh]

Can you see if the fast idle cam is actually moving? Sometimes they are sticky, and it would explain the intermittent function.