when my car warms up the temperature is normal the needle stays in one place. ill continue to drive for a little and the temperature will drop down... doesnt make sense obviously cause engines dont get cooler when there runnin longer.. i thought it was my cluster. so i replaced it and same thing happens the needle just drops after a period of time then will go back up randomly.. any suggestions? thanks

 

its probably just the thermostat opening and closing depending on how far the needle drops it seems like normal oporation to me ..thermostats are pretty cheep n easy to replace ..............or check to see if your radiator fan stays on all the time that could promote to abnormal cooling characteristics if its the fan it could be a stuck really maybe even a cts problem

 

could abnormal cooling lead to wierd a/f ratios?

 

yea i thought it was my thermostat imma fix it soon! thanks man

 

agreed on the thermostat.. however with a new thermostat i still get a little bit of needle play during the winter. on top of it taking like 20 minutes to warm up the car

as long as it dropping and not raising ur safe

 

well, when i first start up my car it runs all the way rich(using a narrowband o2 sensor and gauge) then it slowly goes down to all the way lean, stays there for like 20sec and slowly goes up to optimal, then shoots up to rich and stays there. until im driving at highway speeds for 5-7 minutes itll start to go down to optiml but only when im on the gas. and if i continue at highway speeds it goes leaner and bounces alot between lean and optimal dependin on throttle position.

 

that wouldnt effect proformance would it?

 

you should get a wideband to get a more accurate reading. the leds are always bouncing around someplace making a light show on nB. their only usefull to see if your pegged lean and need to stop the car or pegged rich. anything in between is a shot in the dark

-2 cents

 

its always pegged rich. except when i first start it up its pegged rich, goes all the way lean then back all the way rich

 

i apologize for thread jacking lol

 

its cool bro haaha!

 

the a/r ratio is correct its supposed to bounce back and fourth for optimal cat. efficiency also on startup the car is in open loop and isnt getting a proper o2 reading cause the motor and o2 are not warmed up after a certain amount of driving the vehicle will go into closed loop and the gauge will start to fluctuate between lean and rich .....its never gona stay on stoich

 

i had mine do this one time when i would get on it i guess fluid would push past the thermostat and i replaced the thermostat and this all stopped the lil O-ring int he middle was leaking.

 

im experiencing similar issues. when cold to warm up, it seems like you say. i have an oil temp gauge(someone gave me) and at 150 degrees or higher. the gauge goes full lean when cruising. after 3k rpm the gauge goes rich. you can feel the transition. whats going on here?