Hello there! My 8 is a 04, I change the coils and did an upgrade to the ls2 coils, with the harness and everything, I was having a issues with the old coils, they were getting hot and you can hear it cracking after the car turn off and not starting back until it cools down, so I changed it, did the upgrade and the problem go worst, now when I turn the car on it only stays on for like less than a minute, have one guy saying that the next thing could be the ecu, but I don't feel like wasting my money and my time for a new ecu if their is no need for, hope somebody can help me, I'm desperate for help, thanks in advance

 

It's not the ECU. Have you had a compression test? Hot start issues are commonly a sign of low compression.

Not being to stay on longer than a minute is sometimes a vacuum leak or MAF sensor issue. Does the car have intake mods?

 

Plugs and wires too? Starter? Are you getting any CEL? Shutting off after it's been on for a short while sounds like a compression issue.

 

Yes we did a compression test and it was good, no it doesn't have any mods at all, the thing is that we can not scan it because is not staying on long enough to give us a code, but it shouldn't be the ECU then, because if it was the ecu it won't even start, right?, thanks for the help, any more will be appreciated

 

Yes, all that too, we even try with another set of coils with wires, and it did the same thing, and what's CEL, I'm bad with acronyms, but we did a compression test and it was fine

 

CEL= check engine light.

verify that your MAF (mass air flow) sensor isn't damaged and that the air filter isn't clogged. Make sure your intake tubes are all connected securely and no cracks. Check and clean your eccentric shaft position sensor (commonly ess or esps).

EDIT: Lastly, read the following links:
https://www.rx8club.com/new-member-f...t-here-202454/
https://www.rx8club.com/new-member-f...ot-8-a-202548/
https://www.rx8club.com/new-member-f...%2A%2A-245479/

 

You should be able to read any fault codes without running the engine, so I'm not sure what you mean by "we can not scan it because is not staying on long enough to give us a code". Either way you should see a CEL.

A lot of ECUs that are diagnosed faulty aren't necessary, it's more often a wiring or sensor issue. If it's one of those then yes, it's entirely possible that you can start the engine and it'll die soon after.

What sort of numbers did you get on the compression test?

 

Alright I will be checking on all that and see what happens, and thanks for the schooling too!

 

I forgot the compression test numbers, but they are good, the thing with the codes is that we disconnected the battery to install the new coils and all the codes disappeared, thanks

 

Was the compression test done with a regular tester or a rotary one?
If you've completely ruled out a vacuum or unmetered air leak and cleaned the MAF sensor, try cleaning the Eccentric Shaft Sensor. But I still think it's a vacuum leak. There are a few fiddly small vacuum tubes around the air box which you would have had to remove and maybe forgotten to plug back in.

 

all good advice here.

I strongly recommend soldiers reading list.