I have a 2009 Mazda CX7 diesel that "diesels" when I try to star it after a long drive. It will usually start on the second or third try.

I'd check coolant flow and cleanish green anti-freeze...'cause the engine runs a little hot...because there isn't sufficient coolant flow...change the coolant and equip a brand new thermostat...should fix it~ perhaps seasonal coolant flushes were not performed~

hey tennisshoes..the power to the fuel pump would be cut...so really is incapable of dieseling unless something was up with the fuel pressure relay gettin' stuck....whatdya think?~

Hey all. Thanks for the replies. Another one for you. If your car starts "dieseling" when you're trying to start it especially when it's hot and it might take 3 or 4 starts before it catches I lucked upon the fix. My mechanic thought it was fuel and other folk thought it was the pump or injectors. Turns out the battery died ( after 4 years) and when I put a new battery in ( thank you RACQ ) the problem was fixed. Go figure. Still