RX8 nightmares

[fullard]

Hi guys, have you got any ideas what to try next ?
Just taken delivery of second hand Rx8. Ran fine for 10 miles. Then cut out at junction. Difficult to restart then lost power big time and got very hot (smoke out of handbreak apt.) AA diagnosed coil pack fault. Towed to Mazda independent noted specialists who has fitted 4 new coil packs,new plugs,new leads. Wanted to replace Cat but I declined as it had been replaced 4,500 miles ago & their cost was £900 so far ! They Checked compressions all good. All recalls done, High speed starter motor, New Battery, etc.
Ran ok after but Engine light still on. Fault code now - PO 302 - I Removed Lambda probe, looked fine, blew out with airline. Done 80 motorway miles today hoping it might clear cat out but it cut out at lights twice and struggled to restart. Doesn't seem to rev as freely as remember they do either. Should I bite the bullet and fit new cat & lambda or is it worth Gutting the cat ?

[waxaholic]

Take it back to the seller and express yourself in a manner that fits the pile of scrap that you have paid for.

[lexusboy]

Was a genuine cat or non genuine fitted?

[PaulKemp]

The code also points to fuel issue which could explain cat replacement

http://www.engine-light-help.com/P0302-check-engin...

[fullard]

Thanks for reply folks. Genuine cat fitted. Also noted genuine cat fitted by main agent when car had only done 4,000 miles from new! Now 88k. Had car connected to gas analiser at MOT station yesterday, showed MOT pass results good. Still easy to stall at junctions and a real pain to restart when hot using standard factory methods. I believe you can trick system by jiggling Fuel Fuse or Fuel pump connection when start problem occurs but this is a big problem when you're holding up the traffic. Do you think it would be worth/safe, connecting remote switch with relay to the fuel fuse so could be controlled from drivers seat. I'm being told, when these rotarys give problems like this they can never be fixed without new engines ! Mine does not use oil or blow out smoke. Pulling my hair out !

[otolith]

Hot start problems = poor compression = rebuild imminent.

[fullard]

Compressions excellent !!

[otolith]

What figures are you getting?

[fullard]

All very even 7+.

[otolith]

Those should be fine.

Some cars had their starter motors upgraded under warranty because of warm starting issues. There was a lot of suspicion (which I share) that this was usually just covering up poor compression, but perhaps not.

[PaulKemp]

If that is 7 bar 100psi is that standard for an RX8 as most piston engines will be 10 to 12

[otolith]

This is what Mazda work to:



Fullard, I'm assuming the test was done with the engine hot?

[fullard]

Yes. Compressions taken when hot. Having just spoken to the Mazda specialist who carried out last weeks work for me. They reiterated, my compressions are good. They had turned down minor work yesterday on an RX8 with compressions around 5 & just under.
Have you any thoughts on cleaning/replacing internal EGR valve ? This is a Renesis 2005/54 plate, I believe they don't have an external EGR ?

[otolith]

Not something I've heard of causing a problem, though I've been out of RX-8 circles for quite a few years now.

Usually problems with the cat manifest as loss of power and reluctance to rev at high revs. It's quite possible that the incident you describe damaged the cat, though.

[fullard]

Yes, that's my reasoning. I've been offered the fitment of a gutted cat this afternoon, as a test before buying a new one. Currently car does not to rev at high revs (feels like it's had enough at
6500 rpm) which is not how I remember rotarys, and would suggest restriction in cat.

[otolith]

That does sound typical, yes.