relians

my 2004 rx-8 just began doing this. After I drive for a while, I have to wait about 15 minutes before starting again. The motor cranks but just doesn't seem to catch.

RX8Soldier

iTrader: (24)

doesn't sound good.
How many miles on your engine? When did you last change coils/ plugs? Have you had your cat checked?

relians

118,000 miles, plugs are about 18 months old, as is the cat.

longpath

iTrader: (1)

If the coils and plugs are good, take it out on 100 mile trip with a can of seafoam in the fuel tank, and see if that does it. I was having the same problem and it went away after a week of commuting 50 miles each way (it might have been resolved before then; but I didn't think to test until the end of the week).

DeViLbOi

iTrader: (1)

Im going to put my money on the starter and call it a day. Those with older starters have known and documented issues with the starter. Do a search on warm start issues and I'm sure you will come up with a good number of posts on it along with the model number you need to look for when buying a starter.

m3pkrobert

iTrader: (1)

check the connections on the starter and make sure they all in good condition, because I was having the same problem and I even replace the starter but it was the connection that was loose, after I fixed my problem went away

EDZRIDE

iTrader: (1)

Time for a compression test after you rule out the coils.