2000 Accord V6 automatic will not start
 

Upon occasion it would start, run rough, shut off and then do the same thing about 3 times until I could ease it into gear and get it up to speed then it would run fine. Today, it would not start at all. The motor turns over fine but will not start. When I mentioned it to my mechanic in the past about starting, running rough, shutting down, he said he would start by checking the fuel pressure. Now I'm hearing main relay and ignition switch???

Yes it could be the main relay, or ignition switch, or failing fuel pump, has the car had a recent tune up, failing compression, we are working on limited information, so most answers will be in general. Sorry, we try to do our best.

Thanks for the reply. I am going to start by checking out the ignition per the instructions about checking for continuity between terminals 1 & 4 (I believe it was 1 & 4 - I am going to double check).

Well, yesterday it would only turn over but never start. Today, it started right up, running smoothly, no problems so if I did tear into the dash to get to the ignition and it works fine now, what would I gain?

Per your previous questions here is some pertinent info:
1. Current mileage is 305,000. Does not smoke or burn any oil.
2. One coil pack that was bad was replaced 12/08, along with 6 new spark plugs
3. Timing belt and water pump replaced 1/10
4. All motor and transmission mounts have been replaced.

That is what has been done to it since I bought it with 236,000 miles on it. It runs great except for when it doesn't start, or it starts and runs rough until I can get it up to speed.

2000 Accord V6 won't start
 

Today I tried to buy a main relay - none in stock. While at the parts store the codes were pulled. No lights but 10 codes - all misfiring cylinders. Codes were cleared. These no doubt occurred during one of the times when it would start, run rough, die, and repeat.

When I got in the car to leave, it would turn over but not start. Codes were checked again - no codes. Then it did start and run fine!?!?!

No one has given me a clear indication of where the main relay is located just that it is under the dash on the driver's side close to the steering column. By itself? On a block with other relays? There is a block with 2 oblong relays and one square one to the left of the column. Could one of these be it?

Yes, the fat Rectangle with 7 spade connections is the main relay. You can reach up under and gently pry the guts out of the plastic mounted case and save lot of headache. Detaching from the bracket is a pain and removing the bracket via one screw makes it hard to put back together. The circuit board will drop right out if you gently pull on the connector and release the two tabs on the casing with a small long screw driver. The new one will be of the same design. Hope this helps someone.