I have a question my Toyota pickup. It is that it has a problem with idling. When I start it up in the morning it will be idling at about 2500 to 3000 rpm. I tried turning the idle screw down which worked until it warmed up and the was idling to low. It also after being warmed up will idle irregularly when I come to a stop. It will go from 1500 to 2100 rpm's and then back down and will continue to do this until I put in gear and start driving again. If you might known what the problem is please let me know. Thanks for your time. Zues

Have the Ignition Control Module tested, for free, at AutoZone. The tachometer wire likely attaches to the ICM inside the distributor. The tachometer is driven by the ICM. Hence, problems with the ICM are often reflected by fluctuating rpm. The link below may help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563-3.html#post260436

I'm not an expert on Toyotas, but kitch428 is. Hopefully, he'll see your posting and chime in.