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The ECT basically works like a choke. It tells the ECM the coolant temp so the ECM can decide if the engine needs to be rich (cold) or it can be leaned out (warm).i went out today to check the ignition timing but got side tracked. it’s throwing code 21 again which is ect out of range. Turns out the pin is pushed to the back of my connecter. Could this cause the rough idle?
also how do you get ur motor to TDC to check ur ignition timing
It should just click on once to run the pump with the key on engine off...but youre getting good fuel pressure...if the relay waa bad i would think it wouldnt run the pump and you would have no pressure.I got a fuel pressure tester, tested the fuel pressure and it to where it says it should be. I looked it up and it said from 35 psi to 40 psi and it stays at about 40 the whole time and does not lose pressure but I did realize when trying to start the truck the green relay I think it’s the fuel pump relay clicks continuously. If leave the key turned over for a little bit while the engine is off the relay will click continuously also. The truck does not want to start when but when it does, It will run for a few seconds then you hear the relay clicking continuously again and then the truck dies. Could this be a wiring problem or bad relay? Could this cause my issue?
It should just click on once to run the pump with the key on engine off...but youre getting good fuel pressure...if the relay waa bad i would think it wouldnt run the pump and you would have no pressure.
It should just click on once to run the pump with the key on engine off...but youre getting good fuel pressure...if the relay waa bad i would think it wouldnt run the pump and you would have no pressure.
You can try the relay...but im wondering if its ECM related.
okay thank you! could this relay issue cause the problems i’m having?Yes, disconnected ECT will set code 21 Engine Coolant Temperature (ECT) sensor out of range – ECT
You know where the OBD1 test connector is
Drawing here shows the Fuel pump slot on the connector: https://www.therangerstation.com/tech_library/images/eec-iv_testing2.gif
That slot is the Ground for the fuel pump relay, that slot is connected to pin 22 on computer and the ground pin on Fuel Pump Relay
Turn the key on, engine off
Fuel pump relay should just click one time, 2 seconds on then off
Ground that slot with a jumper wire
Relay should click on and stay on, fuel pump is on
If it starts to click then a problem is with relay OR its 12v side of the coil
No clicking
Start engine
See if it runs any better
While its running remove jumper
If relay starts to click again then a problem in the computer or its pin 22 wire to that slot on OBD1 connector
Just the resistance between the 2 wires
Idle should be higher with Rich mix when engine is cold and then come down over the next 5 min or so until it warms up, that's Choke mode
That's what the ECT is for
That's when the O2 sensor takes over so computer can calculate air/fuel mix on the fly, O2 can't work until is heated above 650degF by the exhaust
The test on the FP Relay ground is more to see if computer is acting up, pulsing the FP relay ground when it should be on full time(when engine is running)
Fuel Injectors are also run by computer grounding them, and goofs there COULD cause rough running