FI injector 'water jacket' sensors

Hi, new to this list, am on WET COAST of Canada. I am getting about 6 mpg, on a 22re FI motor in an '86 4x4 that has about 25, ooo miles on motor. I am going to 'meter' the 'delivery' senders for ..cold start injector..and coolant temp sensors..because, I feel if they are faulty, then the engine would always enable the ..cold start injector..and 'read' coolant as cold..and then 'send' computer wrong 'message', and computer would send out more fuel to engine, because of 'this temp 'read'! Because I can think this way..there must be a 'flaw' in the logic..is there? Everything else on motor, seems to be good, but MPG is ruining my love for this truck! Injectors, coil, etc, all good by tests!

Cheers

Syd

PS The price for the COOLANT FI body sensor, up here are over $200.00 Can....anyone, have a ...'cheaper" one?:confu sed:

Reply 1 : FI injector 'water jacket' sensors

Your logic is correct. MPG that horrible certainly indicates a fuel deliver and metering issue. If that coolant temp sensor is faulty then it certainly could do as you are describing. I believe (but am not entirely sure) that is a negative coefficient thermistor which basically means as the temperature of the coolant increases, the resistance of the sensor decreases. The computer sends voltage out to it and depending on the resistance of the sensor it will see a percentage of that voltage back. The amount of voltage it sees back indicates the engines temperature.