Coolant Temp Problem

rhecht · Post by **rhecht** » Mon Mar 29, 2004 2:49 pm

I'm having a problem where the fuel mixture is leaning out when the coolant temp reaches normal operating temperature.
The car almost stalls out when I come to a stop and it also leans right out to like 16:1 when I blip the throttle or under hard throttle conditions.
However the mixture then goes to stoich (14.7:1) when I'm cruising at part throttle. Everything goes back to normal when the coolant temp comes down a bit below normal temp (half on the gauge).
I'm wondering if anyone has had this problem before. I have an S200 system without the datalog option so I really can' t tell what is happening with the sensors. However I have checked the following sensor to be all within spec (MAP, TPS, TW,TA, IACV, FIV).
One of my friends mentioned that this problem could be related to the thermostat that I'm using. I am using a Spoon thermostat which opens at a lower temperature than the stock one, I have the spoon thermoswitch for the fan to come at a lower temp also.
Any help would be appreciated, I will be trying a stock honda thermostat next unless somebody else knows why this is happening.

fox30 · Post by **fox30** » Tue Mar 30, 2004 9:05 am

seems like you tuned under the normal temp. maybe your base map needs to be richened a bit,

after you do, you will probably need to decrease the ect fuel mix so that warm up wont be too rich after the change.

rhecht · Post by **rhecht** » Tue Mar 30, 2004 5:55 pm

After reading the "sticky" above about low temp thermostats, I think that this has a lot to do with the way my car is running. Although I ran it in warm temps before and I never had this problem.
It almost seems like the thermostat is stuck closed and only a little coolant is flowing past.
I will be changing both the thermostat and the "TW" Water temp sensor since the gauge is acting funny too.
Thanks for the advice, I hope to tune this setup properly soon as well.