broken coolant temp sensor

[omega_rugal]

While doing some cleaning on the MJ`s 4.0 accidently i broke the coolant temp sensor... ups my bad... the truck works but still the ECU is blind to the actual coolant temp, i read the EFI manual and says that the coolant temp alters the timing of the spark but ti doesn say how, cool or Hot = advance or retard? i`m confused... it also alters the inyection timing but is irrelevant, LPG only from now on...

 

any ideas?

[Tactical Bacon]

Generally at the extremes of the temperature range the ecu will add fuel. It doesn't really pull advance when the coolant is too cold but it will pull 5-15* on most FI vehicles at high temperatures. Without temperature input, the ECU will default to a certain range of values once it goes into closed loop mode that will limit timing and add fuel to protect against detonation. Some vehicles will also stay in open loop when there is no input from a coolant temperature sensor. Open loop is bad because the computer doesn't process any input from the O2 sensor, MAP, IAT, or ECT.

[HOrnbrod]

While doing some cleaning on the MJ`s 4.0 accidently i broke the coolant temp sensor...

any ideas?

 

Replace it.

[Eagle]

Should we assume this is a Renix era MJ?

[omega_rugal]

yes it`s a Renix

 

 

Replace it.

 

of course but if it works without it? the FI is not even conected...

 

 

It doesn't really pull advance when the coolant is too cold but it will pull 5-15* on most FI vehicles at high temperatures

 

interesting, i could use that advance....

[Ωhm]

Doesn't CTS affect IAC for the choke function? I think CTS is a high priority for IAC and INJ PW (when/if connected). 

[64 Cheyenne]

"FI not even connected" and "LPG only from now on" are we missing something here?

[omega_rugal]

yes, the ecu is just controlling the ignition now, no fuel pump, no fuel rail, nothing gasoline related...

[cruiser54]

Are we talking Coolant Temp Sensor here?

 

Kinda hard to break one off.....

 

Or, are we talking Sending unit for the gauge on the back of the head which is easily broken by some folks? 

[omega_rugal]

is the coolant temp sensor, the one on the bottom of the block, may be it was aged and brittle already....

[Eagle]

Yes, the one on the lower block is the coolant temp sensor for the ECU.

[Airborne Janitor]

Does it look like mine?

 

[cruiser54]

Does it look like mine?

 

That's a knock sensor. 

[omega_rugal]

yes that one... knock sensor? i don`t need that with LPG anyway... that`s a relief...

[Airborne Janitor]

 

That's a knock sensor. 

 

Thanks for the correction!