When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Troubleshooting my lack of idle up when cold. i need some datapoints.
On your 22re, tell me outside temp and how long your truck fast idles on cold start before settling down to normal idle speed.
thanks for you input.
I haven't thought much about how long the fast idle lasts since I got my I.a.c.v. working last year. It's been great having it at all, winter starts used to be such a PITA!
Tomorrow I'll fire it up and post the outside temp, fast idle rpm and how long till it drops down to 750 rpm.
Started up at 10:12am and the idle sat at 1300 rpm.
Took 5 minutes to fall back to 750 rpm. You can see on the temp gauge the engine was just starting to warm up.
Hope that helps. Fyi, I set the i.a.c.v. adjustment screw so the internal plate is as far open as it would go. It would be easy to carve out some plastic to open it even more, but I'm happy with the result I got.
Yes, temperature does come into play in the i.a.c.v. When it's hot out (upper 90°s) my "cold start" idle is under 1000 rpm. I'd guess that at even hotter temps, the first start of the day wouldn't be any different than a warmed up engine. On the other end, the little sliding plate inside the valve can only open as wide as the air passage to the tb, so even on the coldest winter days I don't think I'd get more than a 1500 rpm fast idle.
Yes, temperature does come into play in the i.a.c.v. When it's hot out (upper 90°s) my "cold start" idle is under 1000 rpm. I'd guess that at even hotter temps, the first start of the day wouldn't be any different than a warmed up engine. On the other end, the little sliding plate inside the valve can only open as wide as the air passage to the tb, so even on the coldest winter days I don't think I'd get more than a 1500 rpm fast idle.
Thanks very much for the data points. Clearly mine is not working correctly. On the coldest mornings we've had so far, maybe 50F, it starts right up but settles into normal idle speed (850 or so) after a few seconds. I know the air valve is operating because I was able to blow through it and flow was different cold engine vs hot engine but maybe it's not operating at the correct rate.
Hmmm. Maybe it's barely open and it's closing right down? Although that would seem not to be the way they fail from what I've read... now I'll have to take it apart.
Other things that I've tested that look OK:
Airflow meter- all resistance readings as shown in the shop manual. verified air temp sensor changed with colder weather.
H20 sensor - resistance as shown and verified it changes with water temp. have not cleaned the threads or sender, though.
cold start injector- was a little carboned but cleaned it. verified it read correct resistance and opened with 12V. Mounted it backwards and sprayed about a teaspoon of fuel into a plastic soda bottle while cranking.
That other sensor next to the H20 sensor. - correct resistance per shop manual.
No codes.
This has got to be a mechanical/organic problem because the engine thinks it's working correctly.
Last edited by Melrose 4r; 10-06-2017 at 09:06 AM.
I'm in socal never all that cold and mine always starts up at 2000rpm.. Gets to normal idle after a few minutes but I wonder if something s wrong now with such higher rpm than you guys
I'm in socal never all that cold and mine always starts up at 2000rpm.. Gets to normal idle after a few minutes but I wonder if something s wrong now with such higher rpm than you guys
Is yours carburated? They're supposed to have a higher-rpm cold start idle than EFI.
If the engine does not buck, or die, why is any higher cold idle speed necessary??
Yes very stable. runs perfectly otherwise. Necessary? You'd have to ask the Toyota engineers but my logic would be raising oil pressure/oil delivery to top end on a cold engine sooner is better.
But I'm basically just ticked because I know it's not doing what it's supposed to and I want to solve the puzzle.
Last edited by Melrose 4r; 10-06-2017 at 10:29 AM.
paid more attention. 1st start yesterday morning, air temp about 58*, engine initially idled at 750 rpm. so, no stepped up idle with the warm morning. thursday night is supposed to go below freezing, so friday morning i'll try to get another data point.
overnight was 32*. started the truck @ 34*. begins idle at 750, and slowly crept up to 950 or so. stayed there for a few minutes. then i drove it. idle back to 750.
Last night was our coldest night yet, mid 40's. Today started the truck and it did appear to idle faster immediately after startup only for about 2 seconds, then down to about ~950rpm and ran well. After a few minutes driving it seemed to be back at 850rpm or so(how I have it set). So I'll have to try a couple more times, but it seems it wants to fast idle, IF it is cold enough outside.
I plan to take a closer look at the IACV and the ports on the intake plenum it connects to. I think the valve is working correctly but if the ports are gunked up, the system won't work as designed.
10-05-2017, 06:08 PM
