This is a great car, when it will start. I rely on my local mechanic, he has changed relay switch(?) The car struggles to start but finally turns over. It does this for a few days, then won't start at all. I'm scared to use the car, might not get back. Engine cranks and cranks but does not start. Finally took it to Honda dealer; wants $1100 for the "engine computer" Wow! I've seen some great suggestions in the answers but where can I get that kind of expertise, besides being fleeced by the dealer. What can I do to get this thing to start?

. Does the Check Engine Light come on and go off after 2 seconds, when the ignition switch is turned to ON (Position II)? If it does, the ECM is likely okay. If not, 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.

Should the ECM fail the K-Test:

. Buy a remanufactured ECM from O'Reilly Auto Parts for around $275, with a lifetime warranty.

. Install the ECM yourself:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-3.html#post235038

Turn it into a flower pot

Or send it back to where it came from