I was driving my Legend last week with no problems. A few hours later I was getting ready to take off and the car would not start. Symptoms were consistent with a main relay failure. However, I just replaced the relay two year ago and dropped a JDM engine earlier this year. When turning the ignition the relay clicks as it is supposed to. Did a code test through the ECU and found that it was 15 - Ignition Output signal. Just to be safe I bought a new battery, replaced the cables, and replaced the igniter unit and still no start. I think that the coils are good but I have not tested them yet. Can someone offer any suggestions.

 

Verify that your grounds are tight, especially the one next to the igniter. When you turn your key to the II position, do you hear the fuel pump priming? Is the car cranking but not starting?

 

Ari-one, I appreciate your time in responding to my post. I was getting ready to test my coils on Saturday and when I took off the valve cover I noticed that the ground to the coils was loose and the bolt holding it in place was not tight. I tightened it and the engine fired right up with no problem. Ran it for a few miles and it's actually running better than it has for a while. However, sometimes when idling the rpm's will rev up and down between 1000and 300 rmps. When I rev it up with the pedal it seems to calm down. It was suggested by a friend that I should remove and clean the IAC valve. Any thoughts would be appreciated. Thank you.

 

Ari-one, I appreciate your time in responding to my post. I was getting ready to test my coils on Saturday and when I took off the valve cover I noticed that the ground to the coils was loose and the bolt holding it in place was not tight. I tightened it and the engine fired right up with no problem. Ran it for a few miles and it's actually running better than it has for a while. However, sometimes when idling the rpm's will rev up and down between 1000and 300 rmps. When I rev it up with the pedal it seems to calm down. It was suggested by a friend that I should remove and clean the IAC valve. Any thoughts would be appreciated. Thank you.

 

Ihad the same problem with my legend and in the end it was the main relay it was a faulty diode. worth a look at another main relay.trust me

 

The revving can also be caused by air in the cooling system, make sure to check the level of coolant in the reservoir and the level of coolant in radiator (when COLD).