Nord546

Hello, as the title says, I have problems with the hot starts.
I have a Mazda RX-8 2004 High Power with 75 *** Miles on the meter that is always serviced properly.

I bought the car defect and the car was in limp mode and the previous owner could not fix the car and sold it away a bit cheaper, I thought i could earn some money on the car because I thought it wasnt a big problem with the car.

I drove the car home about 200 miles and took it to my dad's shop (BMW) and DTC searched the car and then I got error code on the oil pump, and then I thought, what a relief when I change the oil pump maybe the car is running fine!

Time passed and I bought an oil pump on ebay and installed it and the car started without a limp fashion and worked! Great!

Then went out on the first test drive, and the car was great! I went back into the garage and parked the car but needed to move on it immediately, and then I noticed .. It did not start again.

Then I began to search the internet and read some things that might be worth and change and can cause severe hot starts.
Many claimed that the starter may be the problem so I bought a brand new starter of the newest version, installed it, and started the car, and as usual, it starts fine when it was cold so I went out and test drove and hoped that it would work, after about 40min test drive so I went back to the garage and turned off the car and tried and start and it is still running hot ..

Then I went on and search for information, and the only sensible thing to change was the spark plugs, and then I did it, installed brand new as a friend on Mazda ordered and the car starts great as usual, but still dont start when hot.

Now I really dont know what to do.

Coils and ignition cables I do not believe to change because then it should affect the start when the car is cold too.
The strange thing is that the car starts just fine when cold and running just fine, but warm, it dont start.

I have not done a compression test yet and believe it to be the next thing to do but neither we at BMW or Mazda workshop her in Sweden has the right measurement tools for the RX8 but i might solve it somehow.

But I really do not think it's bad compression in the car. Because its runns very good AND on our way home when I bought the car, I shut down and restart the car safely 10 times when the main fuse had gone and the car did not charge the battery, so I had to stop and change the battery whilst on our way several times and the car started just fine hot.

Its also not a problem with the battery because i always have it hooked up with cables in the garage when starting.

I have read that it can be the fuel pump but what do you think?
Really need your help with this, I do not know what to do anymore!

Sorry for my bad English and hope to get some help with this.

Sincerely Linus from Sweden.

reni04

Is it a automatic or manual?. You are having the same issues i am and i have been asking here at the rx8 club for several months and no answer only for manual trans cars. The issue is if yours is an automatic then the starter is a N3H1. I have had the same problem in finding a upgraded starter for the automatic starter. I am afraid that this is too technical a question for this group of folks because i have had to resort to now asking in Pm's to different folks and so far no answer i have been asking for 5 months and don't bother asking Mazda , they seem to know loittle to nothing at least they couldn't tell me that answer as well as no one here at the rx8 club has that knowledge , do you know?. If you find out post it please. I thought this was a no brainer question.what is the proper designation for a up graded starter for the rx8 but so far i think it seems to be beyond the so called experts here so i am stumped ???.

Steve Dallas

Difficulty in starting when hot is the classic sign of low compression, unfortunately. The other main cause is a faulty fuel pump. You need to have a proper compression test performed, before you spend any more money on the car.

A note about coils. They typically last less than 30K miles on this car and are considered wearable items just like spark plugs (the wires are too). They need to be tested every 10K miles. Bad coils are very common and cause all sorts of problem, including clogged catalytic converters, which then cause low compression.

Upgrading the starter can help get the car started and put off the inevitable for a time.

This is a thread you should read:

https://www.rx8club.com/new-member-f...causes-249529/

reni04

Thank you for the response; For the benifit of automatic owners that may read this searching for the same answer i was , and that is what is the stock 2004 and maybe 2005 starter # and that is N3H2 for the automatic and N3H1 for manual. The upgraded starter is N3H2-A. The Mazda dealer is selling a reman upgraaded starter and the number is N3R2-18-400rob for the automatics. So if you find a N3H2-A you have a upgraded starter and i believe they are 2.0KW at 2.62 HP. The old N3H2 original starter was 1.4 KW so no brainer which is better.

You are correct sir , a compression test is a good idea. I already have the N3H2-A starter in my parts bin so i will install it and report back this spring when it is warm enough to get on the creeper and give a report on how it worked out. I know thsat the compression test should be 120PSI max to 98.6 minium with a fifference between combustion chambers of 21.8 at around 250 rpm. Just sayin. Thank you and i hope this helps some one as well.
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