Help needed! hot start and idle problems!
 

Hello everybody,

So, my rx8 does not idle what-so-ever and it will not turn on when hot started, but will turn on within milliseconds @ cold. I replaced the plugs, changed the oil, and cleaned the maf sensor with choke cleaner. What do I do next to root out bad compression? What are the symptoms of a bad cat and what are the symptoms of bad ignition coils? Also, could this be related to the three vacuum tubes on my intake accordion hose that are not sealed on? (Two of them will come out with the plastic right angle adapter attached to them) Oh, and I also installed the newer n3z1 starter and the battery is great. (I even used another car to jump start it)Also, there is a check engine light on. Does the computer detect compression and notify you if it's bad with a check engine light? Thanks guys...I'm beating myself in the head with a hammer until I get this fixed.

Low compression can't be fixed with parts. The only thing you can try to solve that is the ATF trick or seafoam but other than that my bet is that your motor is toast.

your next step should be to bring it to a mazda dealership (or to a rotary specialized mechanic) to have your engine compression looked at, before that hammer breaks your skull...

edit: click the google link in my sig, and use key words like "hot start issue", coils" etc, as key words

So, do you think it would be safe to say if i pour some auto tranny fluid in there and if it idles when cold then...then it's compression? Or do you think there are other things that would make a better test? I guess I should just compression test it with a normal compression tester that I could try using my video camera on and then slowing it down on my computer to see the 3 sides of each rotor.

Do you guys think I could work my magic on a mazda dealership to get the engine replaced? It's an '04 and it has 78k on it. I think it was purchased in '03 though :banghead:


And I tried searching... I know how to google. "site:rx8club.com". Thanks though. I just wanted to get some more specialized advice, since everyone just says to change your starter.

Read up on how a full ignition system works (coils>plugs>cat converter>kaboom)

From your post, you seem to have MANY potential issues as to why your car is acting up. What I mentioned are usually the first things to check.

However, those tubes not sealing to your intake could be an issue.
The CEL that your engine is throwing could solve this (have it read)
Have you reset the ECU after cleaning the MAF sensor?

Many issues. Start the process of elimination...

Well, tomorrow, I'll just test the compression. Then from there we will see how it goes. Is everyone else in favor of it being moderately easy to test rotaries with a normal compression tester if you remove the valve that you can see the 3 spikes in compression? Does it bounce back so fast that i need to slow it down with a camera?


Oh and... trailing or leading holes to test compression?

Also, can my engine still show bad compression if it is really carboned up? Or would the carbon have to be so bad that the engine would not start?

You really should use a rotary specific compression tester. It's the only real way to get accurate readings.

So, filming the compression tester bounce and then taking it to my computer and slowing it down will not be accurate enough?

that will get u in the ball park, what year is it? you know about the 8 year 100,000 mile warenty ?

that will cause an iffy idle and she will cut out!

the only real corse of action before waxing anymore hard earned pennies is to have a rotary compression test done


the comp test you are describing will give ayou a ball park figure but you could really do with cranking speed (even tho you know you have a faster starter) as this goes hand in hand with compression :rolleyes:

I did a compression test today. Both rotors and all of the faces, are hitting around 40-45psi. It's weird that they were all even. I was suspecting one to be good and the other to be bad. Is this normal? Or did I not do it right? Does this mean that whatever seals off the essentric shaft is bad?


Another thing to verify the low compression is that I have no blinking check engine, it's just solid. (I've watched some videos and it seems like it always blinks if there is a fault with the ignition coils). Also, You guys are going to think i'm stupid, but i tried to do a burn out by dropping the clutch at 5.5k and it seemed like I had very very little power. I drove my friends 240 around today, because it was super nice out, and it had loads more stand-still torque.




One last thing, Can anyone recommend a good shop around PA(in the tri state area) that will rebuild and port this motor? I just want to bring them the shortblock.



EDIT: I held the release valve down. No worries people.