91Toyota

Okay, lets figure this thing out. Symptoms: Barely idles when cold (idles really low ~500-600rpm), surges when hot, idles too high when hot, idle changes

Now, I can't just turn the idle screw down...why? Then it won't idle when its cold. I adjusted the AAV (air auxiliary valve) and it helped quite a bit. But, sometimes when I'm driving...it will idle normally. So, can I adjust this valve more...so the idle (when hot) is lower but not be any lower when the engine just started. I hope this makes sense.

I understand how the AAV works. But I don't know what effects hot/cold idle.

Thanks again!

abecedarian

set the idle speed when hot

if it dies when cold, there's a problem with the COLD system.
DO I NEED TO HIT YOU ON THE HEAD WITH A HAMMER?

abecedarian

DO NOT ADJUST THE WARM/HOT IDLE compensate for a cold idle problem.

abecedarian

If WARM IDLE is correct, but cold idle isn't... it's a problem with the IAV/AAV... and does NOT REQUIRE AN ADJUSTMENT TO THE WARM IDLE... unless the IAV/AAV is stuck open.

91Toyota

Okay so my assumption is it's a cold idle problem. BUT, it seems to change all the time. I'll make SURE its set to 750rpm when HOT...and see how it acts when cold.

I'll make sure to double check this.

Could you hit me with a hammer?

just a 22re

this time im going mto stay with ya buddy does your cold start injector work did you plug it in right? what about all the connectors or did this just come up from nowhere? to bad you live way to far away or i would be coming over and fixing this thing with ya.....


a few places to start as of now...

coolant temp sencer
coolant temp switch
cold start injector
relays for the cs
iac,,, acc
loose wires on the fuel rail
vac leaks
fuel pressure regulator
thats all i can think of as of now but im sure a few of them dont even mater with the way shes acting on ya

abecedarian

warm is the normal state of the engine, and what the ECU tries to do...
everything else, is separate.
if it weren't why would there be a 'cold start injector' and 'cold start time switch'?
Why would the IAV/AAV change when the engine warms up?

snap out of it!!!!

abecedarian

umm...

91Toyota

Because its "supposed" to close when the engine gets warm...correct? And when its cold its "supposed" to be open to let air in...right?

And since I cut the pellet thing out of the thermostat (now have a new high quality one which i'm not sure if it works yet) and figured the temperature of the engine is changing making the valve open a little and close a little.

91Toyota

Thanks for the offer...but you are too far away. lol. This isn't a problem that just happened. I've had it since I rebuild the engine. Just doesn't want to go away. I've tested the coolant temp sensor...which worked fine. Also tested (I think) cold start switch. No loose wires. Possible vac leak. AAV is new. Also, there is a clog in this....

abecedarian

so... you cut a pellet out of a thermostat and figured your temp should be changing? DUH!!!!
that will happen when the engine is cold and is warming up.

abecedarian

you adjust the engine when it is warmed up.

any problems when the engine is cold are caused by other things.

abecedarian

I thought we've been through this already.

abecedarian

it's like, duh!!!

cold start time switch
cold start injector

do those sound like things that operate when the engine is warmed up?

abecedarian

now maybe the idle air valve/ auxilary air valve are confusing... but...
both of them allow more air around the throttle body when the engine is "cold"

91Toyota

Okay I know what your saying...yes the cold start time switch AND the cold start injector both work only when the engine is cold. I cut the pellet out because the thermostat would not open until it was really hot. I knew my idle would be changing. But now it shouldn't be.

But...my truck idles at approx. 750 rpm NOW. (NEW thermostat and it WORKS!)

When I get off of the freeway its 750...and when I'm driving in town its 1k rpm or so. It changes...thats what I'm trying to say.

The idle screw is ALL the way in. I backed out the throttle screw too. And that is as low as my idle will go. We've been through this...but last time all you talked about was about my low compression...lol.

Now if your saying my AAV doesn't need adjustment then I say BS on that. There is no other adjusting I can possible do to make it idle lower. I GUARANTEE my truck WILL NOT run in the morning. IT will not start.

So...in order to make it run right when HOT...what do I do? I'm pretty sure I should adjust the AAV...right?

Unless you have any other suggestions???

91Toyota

Maybe the dash pot has some blame too. Maybe it is sticking a little and that is why I'm getting some change in idle. But I still need to adjust something to make my truck idle lower when hot. Does that make sense?

High idle/idle screw all the way in/hot

abecedarian

well, most of what you said sounds almost normal... 750 idle is about right...1000 is a tad high though... so maybe the throttle isn't closing all the way, or at least the TPS isn't adjusted properly.

abecedarian

and we're dealing with an AAV that has been modified, and will fVk us up?

abecedarian

so now we've got a throttle body that you've basically torn to shreds, and have to use that for 'baseline' settings.
woo hoo.