Hi guys & girls. Brought an RX8. Here is the background information. The previous owner said his AXA breakdown put the battery leads the wrong way round when attempting to start the car with a dead battery. He took it to Mazda who have checked the car and have said it needs 6 new injectors.
I put the car on the diagnostic and it shows no codes at all. The car struggles to start but can be started using the de flood method I followed on these forms. I started it but it sounded very rough and would only stay on with my foot on the gas. I let it get up to temp and then gave it some gas. The revs did reach to 9k and then it shut off. There was a huge fire underneath the car near the exhaust. I have followed the advice on these forms and all the plugs, coils and leads seem to be fine. Since it is running rough I assume it has a misfire, my question is how comes this does not come up on the diagnostic scan. And also is Mazda right, is this likely to be caused by fuel injectors ?

would really appreciate some help. The car does not start unless the de flood procedure is followed. Prior to the breakdown guys messing with it the car was running spot on.

 

don't try and start it again.

did you get a compression check before purchase? did you check the cat? that could cause a blockages and with you forcing the engine to run could cause a fire.

 

Mazda did a complete check on the car and they said compression is okay.
How cpule I could test if the cat is the issue? If I just remove the exhaust would this be sufficient.
also would cat issues cause the engine to run rough.

 

every question you just asked is answered in the new owners thread, or with a simple thread search no really read this!

spoon fed version: yes, it would cause issues and is caused by poor ignition components.
Drop the cat and shine a light it will looked clogged or not(use google for examples)

 

As for "mazda" saying it's good, is insufficient. They should have given you a minimum of 8 numbers (2 rpm #s, 6 psi readings) again all covered in the new owners thread.

 

No they didn't. I will remove the exhaust and test it out. Hope it's this causing this issue.
many thanks for your help and time mate

 

Were the injectors replaced?

If so, and the o-rings, cups, and grommets weren't installed correctly, you will have a giant fuel leak on the right side of the car.

You can check for a fuel leak at the injectors by turning the key to "ON" without starting it. That will start the fuel pump and prime the fuel system. Watch the fuel injectors and verify nothing comes spraying out.

You can do a basic visual inspection of the cat by disconnecting it from the exhaust manifold. You can also run the car without the cat connected to check everything else.

 

Thank you both

 

Thank you both

 

What's the history of the car? Has it had recent work like engine replacement?

 

No not at all. Car was running perfect until breakdown people put the jump leads the wrong way round and ended up flooding it. This is of course according to the previous owner. Would a misfire cause rev fluctuation?
revs don't move and seem stable just sounds very rough and shakey.

 

Misfires manifest as a flashing check engine light. If it's not flashing, don't assume there is a misfire.

 

It was running fine except it had a breakdown?

 

Check engine light is on. But scanner not picking anything up. Initially the throttle was jamed up and it was throwing a throttle position sensor A error. I cleaned this and the code is now off. However it is not flashing. That's the only light which stays on.

 

Yes confirmed. Car was running fine before this. He basically called them out for a dead battery and then they flooded it and put the leads the wrong way round. To confirm the check engine light stays on permanently and it sounds like it's not getting fuel but following check lists on these forms. The usual suspects are all fine

 

There are manufacturer-specific codes that not all OBD readers can pick up, for example the OMP ones. Not the misfire codes though, those are standard. So if you don't have them, odds are you don't have a misfire per se. What are you reading it with?

The injector explanation doesn't super make sense, since even if they were busted, they wouldn't start a fire. I would ask the dealer how they came to this conclusion. Like Preppie says, if they're physically misplaced and fuel is gushing everywhere that's a related but different problem..

 

 

Well, so replacing all 6 injectors sounds like a strange diagnosis because it's virtually impossible for all 6 to fail simultaneously. Again, I would ask how they came to this conclusion. It's not that I want them to be wrong, but replacing them is the long and expensive way to find out they weren't the problem.

I'd also ask what checks were carried out, specifically. Did it include a compression test? A test of the coils? Eccentric shaft sensor? Fuel pressure? A test of the catalytic converter itself? If it included any of those, Mazda should have a record of the results, which would help us figure out what's wrong.

Also "misfiring and won't start" sound like mutually exclusive statements. If it won't start, then how can you know it's misfiring? Unless we have different definitions of "misfiring"

 

Thanks for your reply. I agree with what your saying. I will ask them and see what they say.

 

The injector harness does have its own ground. I wonder if when the leads were on backwards this is what damaged the injectors. I'm kinda curious if there would be ECU damage as well.

 

Thank you all. Changed catalytic converter and two coils although they were working. When checked for resistance they were a bit off. Car starts up fine now. Looks like the guys on here were right. Nothing wrong with injectors. Just goes to show, Mazda were wrong and the guys on here were spot on.just wanted to say thanks to everyone who responded.

Next thing I need to fix is the steering being harder to turn right and tracking seems off but plenty on here going through this problem. Am sure I can get to the bottom of it 😁😀😁😆