Car has suddenly devloped some sort of running issue.

From cold start up only the car is `sometimes` hesitant, as if one of the plugs is off but eventually it sorts itself out and i can then drive normally again.

One thing i noticed was on the power commender off the Apexi ecu



as you can see the water temp indicated its -42 degrees, this is what happens when its hesitant at driving. once it sorts itself out it goes back to normal. Now sometimes ive noticed when driving fast the temp decreases suddenly, alot!. Say im driving along normally and the temp is around 87.... if i put my foot down through 2 or 3 gears the temp is then at around 70..... surely this isnt right ?

Mapping issue ? or could it be something as simple as a water temp sensor ?

Car is a 94 wrx with sti engine and apexi ecu

 

Coolant temp sensor fault, it's adjusting it's fueling etc thinking its -42c on cold start.
I'd replace the sensor

 

ive got one on order, £27... thanks bud

 

No worries mate

 

How did you get on mate?

 

Got the temp sensor here but not getting it fitted until friday... So i'll let you know then, fingers crossed thats what it is and its nothing to do with the map

 

Temp sensor fitted, problem solved

 

Nice one mate