pls help 89 accord ECU not working (lxi)
#1
06-11-2022, 07:56 PM
pls help 89 accord ECU not working (lxi)
Edited
Last edited by fulloffuel; 08-02-2022 at 05:00 PM. Reason: Edited
#2
06-11-2022, 10:25 PM
Hello, i hope this is the place to ask for help. Is there anyone who can help troubleshoot with me? My ECU stopped having an LED light, aka communicateing/powering up/prming the fuel pump. i got a replacement ECU and I still have the same problem. the car cranks but doesnt start and it has fuel but the fuel pump will not prime anymore. Ive been asking around for help for well over a month now. Im not great at working on cars or troubleshooting electric, but i think if i had more help i could get this figured out. thanks for anyone who is willing.
#6
06-17-2022, 01:22 AM
Service manual
https://www.workshopservicemanual.co...1986-1989.html
You have one already?
You will need an electrical schematic showing the pin out of the connector and/or the wire color.
This will help identify which ones are which. Five volt reference is voltage that is put out by the ECU.
Some goes to the TPS throttle position sensor or the MAP sensor.
If you do not have 5 volts then unplugging a sensor and monitoring the 5 volt reference would show whether a sensor is shorted.
The 5 volts would return after disconnecting the shorted sensor.
Never mind that for now.
Limp home mode?? You have got quite a task in front of you.
Spark plugs or fuel or even O2 sensors can cause problems that lead to blinking check engine light
Where do we start? Guess that would be to see if we can get the engine started.
The timing belt could also be an issue.
Take oil filler cap off the valve cover. Shine a light inside and watch the valves.
Have a friend crank the engine. Do the valves move?
If yes then maybe the timing belt is okay.
If no then the timing belt has broken and who knows what kind of damage the engine has suffered.
We first have to see what is the actual problem.
You say the engine cranks but does not start?
The timing belt is okay?
Then you say the fuel pump does not prime the fuel rail nor does it run?
Do you hear the fuel pump run when the key is first turned to the "on" position?
If not then you will need to check powers and grounds going to the fuel pump.
Do you know how to use a volt meter and test light?
If there are powers and grounds when key is first turned to "on" position (only momentarily)
Then fuel pump may be bad?
If there is no powers and grounds when key is first turned to the "on" position
Then Fuel pump may be good but not getting what it needs to run.
Will then need to go to the schematic to find the fuel pump and trace back to the next unit.
It may be a fuel pump controller (on some cars) or it may go back to a relay?
If it is a relay then need to swap it with a good one to test.
Does the fuel pump run for a second or two when key is first turned to the "on" position?
If yes then does it start? May need to crank for a moment or two to get it started?
If no then not the relay. Must check the control side of the relay and the output (load side) of the relay.
It goes on and on. This is why most people will ask a question and wait for an answer.
You will have to do a few tests and then come back with answers
Unless you have friends who knows cars and can help???
https://www.workshopservicemanual.co...1986-1989.html
You have one already?
You will need an electrical schematic showing the pin out of the connector and/or the wire color.
This will help identify which ones are which. Five volt reference is voltage that is put out by the ECU.
Some goes to the TPS throttle position sensor or the MAP sensor.
If you do not have 5 volts then unplugging a sensor and monitoring the 5 volt reference would show whether a sensor is shorted.
The 5 volts would return after disconnecting the shorted sensor.
Never mind that for now.
Limp home mode?? You have got quite a task in front of you.
Spark plugs or fuel or even O2 sensors can cause problems that lead to blinking check engine light
Where do we start? Guess that would be to see if we can get the engine started.
The timing belt could also be an issue.
Take oil filler cap off the valve cover. Shine a light inside and watch the valves.
Have a friend crank the engine. Do the valves move?
If yes then maybe the timing belt is okay.
If no then the timing belt has broken and who knows what kind of damage the engine has suffered.
We first have to see what is the actual problem.
You say the engine cranks but does not start?
The timing belt is okay?
Then you say the fuel pump does not prime the fuel rail nor does it run?
Do you hear the fuel pump run when the key is first turned to the "on" position?
If not then you will need to check powers and grounds going to the fuel pump.
Do you know how to use a volt meter and test light?
If there are powers and grounds when key is first turned to "on" position (only momentarily)
Then fuel pump may be bad?
If there is no powers and grounds when key is first turned to the "on" position
Then Fuel pump may be good but not getting what it needs to run.
Will then need to go to the schematic to find the fuel pump and trace back to the next unit.
It may be a fuel pump controller (on some cars) or it may go back to a relay?
If it is a relay then need to swap it with a good one to test.
Does the fuel pump run for a second or two when key is first turned to the "on" position?
If yes then does it start? May need to crank for a moment or two to get it started?
If no then not the relay. Must check the control side of the relay and the output (load side) of the relay.
It goes on and on. This is why most people will ask a question and wait for an answer.
You will have to do a few tests and then come back with answers
Unless you have friends who knows cars and can help???