2001 2.7l rich on cold start

2001 Tacoma with 2.7 3rz with 260k miles is absolutely rock solid, and always starts no matter how cold it is outside. Only one issue. When I start it, it runs extremely rich. SO rich that if I start the truck and turn it off (have done so accidentally with the remote start I installed) in the first 5 minutes or so that it's running, it will not restart and seems like it's flooded. Have to wait 5-10 minutes before it will restart. Otherwise this truck runs like a champ, and I regularly see mpg from 17-19 with city driving. Not sure if this could be a sensor going bad or what. Just seems odd that it's so rich it won't restart. Any ideas?

 

Any check engine light? I would verify the coolant temp sensor is reading correctly first of all.

 

No CEL. I assume the cluster temp level is coolant temp? Never any issues there. What would coolant temperature have to do with cold start fuel mixture?

 

Cluster gauge I believe uses a separate sensor from the engine computer on that model. Coolant temp is one of the main factors for fuel control, if the sensor is reading say 32 degrees and its actually 60 degrees on startup the computer is going to give it way more fuel than it actually needs. Once the oxygen sensors warm up and start working the computer uses them to compensate for any errors in fuel control so coolant temp reading isn't as much of a factor then.

 

Thanks for that. I'll whip out the OBDII device and see what it's saying when I fire it up this morning. I figured it would be reading from IAT sensor rather than coolant, but that all makes sense. Future aspirations to boost this motor so I'm looking to correct some minor issues before doing so.

 

Might just be time for a gold ole tune up. Sometimes your O2 sensor can have an effect. Drop a few bucks and do some good maintenance to it. Same happened to my 01 and I just gave it a good ol fashioned tune up