94 honda ex the fuel pump doesn't come on all the time when you turn the key there for it won't start. I changed out the main relay and the fuel pump seems to be fine. It seems like it won't start mostly on a muggy day or if it rained or if it sits for a while. I hosed the moter down to see if it could be a wire but it cranked up.

Does the CEL stay on, when the fuel pump doesn't work?

P.S. Never hose-down your engine--major risk to shorting out the ECM, alternator, or sensors. Also, never jump your battery--same risks.

Sorry my PC been down but yes the cel light stays on,big rain yesterday and today car will not start

The ECM may be failing. Perform the K-Test below:

The K-Test: Remove the MAP Sensor connector and turn the ignition switch to ON (Position II). 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.

In some instances, cleaning the main ECM ground solves the problem.

If the K-Test indicates the ECM is bad, here's how to remove and replace the ECM yourself:

https://www.askmehelpdesk.com/cars-t...tml#post235038

Hi just did that test and got 5 volts, car did start twice yesterday but took some trying, but it will not satrt at all today?