i have a 91 civic hb thats has been mpfi. the car has been running for the last 5 years with no ploblems till a month ago. i was driving down the rode and stopped at a light it shut off. after turning on it for a min or two it fired back up. i drove a 1/2 mile then shut off again and hasnt started since i have replace dizzy, main relays (3) from running cars, ecu,fuel pump,and ignition switch still wont start. i have check fuses wiring resolder all the wires for the mpfi. this has me beat and i need help. i have checked and it seems to me that the ecu is not gettin power cause it not firing or fuel pump wont prime check engine light just stays on wont read any code

Plz help need my baby back up and running

 

Try a different ecu

 

is there a code flashing on the ECU's red LED light? Just out of curiosity, have you had any hesitation from it while accelerating?

 

tried two different ecu's no codes flash light just stay on no hesitation while accelerating

 

http://www.clubcivic.com/board/showthread.php?t=110204

The fine print at the bottom of the picture says to replace the ECU if "check engine light ON and the LED stays on." If you are absolutely sure that the second ECU is good, then I would probably check for clean connection on the ECU plug harness pins. My nissan had a bent ECU pin one time, and it took me a month before I figured it out.

 

The ecu's is good put it in my crx fires right up

 

There's two ways that come to mind when it comes to checking for loose connections. 1) Probe each wire to see if it has the signal it is supposed to.
2) Have someone hold the key to "crank" while you (start with the ecu wireharness) and wiggle/push all the wires to help make the connection.

Since the ECU works in another car and you have a check engine light, I'd guess you probably have a loose/broken connection somewhere.....some signal or ground isn't not letting the ECU operate?

 

so u think it a broke wire or something not getting connection at the ecu?

 

i don't know. What we do know is what you have stated.
1) Your ecu works in another car
2) another ECU still doesn't start your car
3) Your car has no spark or fuel when cranking over (right??)

If all this is true, then it is quite possible that the ECU is not getting the proper signals to crank the car. Get an ECU pinout diagram so you can test any wire that appears to be a POWER or GROUND for the ECU.

If the engine is not actually being spun over and over and over by the starter, let us know. Do you have a copy of the big Factory Service Manual?? We both need one right now.. I can't find it online anywhere.

 

ya all this is true no i dont have a copy of the factory service manual ill try find one today

 

I can usually find my ECU pinouts in "google images".

 

I found my problem the wire that runs from the ignition to the main relay had a break in the wire

Thanks for all the help