Short Cord TSB Starting Issues
 

I have a 2004 2.3s ATX that has an intermittent starting problem. I have taken it to the dealer and they ran diagnostics on it and I replaced the short cord relay cable and the fuel pump relay per the TSB and thier diagnostics report www.finishlineperformance.com/pdf/mazda3/bulletin/01-037-08-1960a.pdf. The fix worked for a few days without problem but today the issue raised it's ugly head again. I have replaced the battery, now the short cord cable and the fuel pump relay so I am starting to pull at straws here. The dealer states that 9 out of ten times the car started so they can not replicate the issue so they do not know what to do? I thought that it could be the netural safety interlock preventing the car from starting but I can't start it in neutral so I ruled that out, then I thought that maybe it could be the TR switch on the ATX but the dealer said that if it was faulty it would have given them an error code. My next step is to replace the starter but the dealer said that I would possibly have to remove the front axle to do this, is this a true statement or I can I replace this myself? Any help would be greatly appreciated in this matter!

The transmission linkage could be loose, causing it to think it's in gear and not start. This will not set a code since it just looks like you're trying to start in gear. In that case just jiggle the shifter, or try starting in neutral instead of park - which should also work. When it doesn't start, I assume you mean it doesn't crank, or does it crank and not start??

Another option is that the intelligent key (I think your year had this too) means you have a start disable if the original key isn't in the car when you try to start it. that transponder could be damaged, or have a loose wire behind the ign switch. In this case, try the second key that came with your car to see if that works. I haven't tried a second non-mazda key to see if it starts without the smart key in place, but those are a few easy options.