Can someone help me out... have 1990 civic and won't stay running starts up for 1 minute thens shuts down... then you can't hear the fuel pump come on after that... if you leave it for a while it will start up and shut down again... checked and replaced the main relay it ran longer then shut down again...

. If the Check Engine Light (CEL) always comes on for two seconds and then goes out, after the ignition switch is turned to ON, replace the Ignition Control Module (ICM) and coil:

https://www.askmehelpdesk.com/cars-t...tml#post265896


. If the CEL stays on at times, when the ignition switch is turned to ON, perform the K-Test on the ECM:

The K-Test: Remove the MAP Sensor connector and turn the ignition switch to ON (not start). Using a multimeter, check for 5 volts going between the MAP Sensor connector's reference wire (+) and ground. As you look at the connector, this is the socket on the right. Really press the black test lead into a cleaned main ECM ground on the thermostat housing. If the voltage is low, it's probably indicating ECM failure. Most failed ECMs will record a fraction of a volt. To me, the K-Test is simple, elegant, and accurate.