omega_rugal Posted February 1, 2017 Share Posted February 1, 2017 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? Link to comment Share on other sites More sharing options...
Tactical Bacon Posted February 1, 2017 Share Posted February 1, 2017 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. Link to comment Share on other sites More sharing options...
HOrnbrod Posted February 1, 2017 Share Posted February 1, 2017 While doing some cleaning on the MJ`s 4.0 accidently i broke the coolant temp sensor... any ideas? Replace it. Link to comment Share on other sites More sharing options...
Eagle Posted February 1, 2017 Share Posted February 1, 2017 Should we assume this is a Renix era MJ? Link to comment Share on other sites More sharing options...
omega_rugal Posted February 1, 2017 Author Share Posted February 1, 2017 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.... Link to comment Share on other sites More sharing options...
Ωhm Posted February 1, 2017 Share Posted February 1, 2017 Doesn't CTS affect IAC for the choke function? I think CTS is a high priority for IAC and INJ PW (when/if connected). Link to comment Share on other sites More sharing options...
64 Cheyenne Posted February 1, 2017 Share Posted February 1, 2017 "FI not even connected" and "LPG only from now on" are we missing something here? Link to comment Share on other sites More sharing options...
omega_rugal Posted February 1, 2017 Author Share Posted February 1, 2017 yes, the ecu is just controlling the ignition now, no fuel pump, no fuel rail, nothing gasoline related... Link to comment Share on other sites More sharing options...
cruiser54 Posted February 2, 2017 Share Posted February 2, 2017 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? Link to comment Share on other sites More sharing options...
omega_rugal Posted February 2, 2017 Author Share Posted February 2, 2017 is the coolant temp sensor, the one on the bottom of the block, may be it was aged and brittle already.... Link to comment Share on other sites More sharing options...
Eagle Posted February 2, 2017 Share Posted February 2, 2017 Yes, the one on the lower block is the coolant temp sensor for the ECU. Link to comment Share on other sites More sharing options...
Airborne Janitor Posted February 4, 2017 Share Posted February 4, 2017 Does it look like mine? Link to comment Share on other sites More sharing options...
cruiser54 Posted February 4, 2017 Share Posted February 4, 2017 Does it look like mine? That's a knock sensor. Link to comment Share on other sites More sharing options...
omega_rugal Posted February 4, 2017 Author Share Posted February 4, 2017 yes that one... knock sensor? i don`t need that with LPG anyway... that`s a relief... Link to comment Share on other sites More sharing options...
Airborne Janitor Posted February 5, 2017 Share Posted February 5, 2017 That's a knock sensor. Thanks for the correction! Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now