Hi All,

I have a 2004 Mazda R8 - automatic. I'm the second owner, I've had it for over 15 years.

If I start it and drive it everyday, it runs fine. If I let it sit a few days, the battery drains down quite a bit - not enough to start. If I keep charger on it, and let it sit for a few days it will start up fine, but smokes for a minute or so. Obviously loaded up. Sometimes pitches a misfire CEL.

Battery is a brand new Duralast Gold. Plugs and coils are also new.

I'm thinking the fuel pump is staying on which drains the battery and also causes the 18 year old injectors to leak. Fits the symptoms anyway. I've ordered up new fuel pump relays, but that is obviously a shot in the dark. I can also pull the back seat and measure the voltage at the fuel pump.

Bad ignition switch might also cause this, but I'd figure other stuff would then stay on. Console lights and such.

Trunk light bulb has been removed btw.

Thanks for the help.

 

It is unlikely that the fuse pump is staying on given the way it is wired. It needs a trigger from the PCM to activate the pump

Do a proper residual draw test and see what circuit is pulling the power and go from there

 

Hmmm - interesting. Your reply helps a great deal.

I guess the 'stuck relay' theory isn't so far fetched. Easy enough to try as replacements arrive soon.

I guess the 'loading up after a few days' part could be the injectors leaking. Definitely smokes a while while the motor cleans out.

Thanks for the help.