Hi,

I have a RX8 2005, which was running fine, but for the past few months, it started stalling when stopping at a red light or a stop sign intermittently, rpm goes too low.

I've been searching the web and reading for possible causes, so here's what have been replaced so far:
- spark plugs
- spark plugs cables
- battery

After all these replaced, it seems to be a bit better, but it stalled again a couple times since. What I've noticed, is that if the fan (if A/C on, makes it even worse), the rpm goes lower intermittently.

Engine usually turns at around 750 rpm at idle speed on a warm engine, but when the fan-A/C is on, it increases resistance, the rpm drops about 200 to around 500-550 rpm for 1-2 seconds, then go back to normal rpm. It does it every 10 seconds or so, but sometimes it's enough to make the engine stall.

Looks like it's when the A/C clutch kicks in, but I'm not sure.

thanks for any suggestions.

 

I have had this exact same thing happen to me. Changing both the spark plugs and ignition coils fixed it for me. The ignition coils are known to go bad quite quickly in the RX8. Mines only had 28k miles on them.

Changing ignition coils are easy DIY, if you changed the plugs and wires yourself you should know exactly where they are and how to swap them.

 

I'm having a very similar experience whereby it's occasionally stalling when idling. I know nothing about cars and have relied on the info I've located here and the work that my father has done for me to get to where I am now, so any assistance is appreciated!

2007 model -- I've recently had my father replace my plugs and coils, as well as clean the MAF, which improved the initial symptoms, but have now led to the stalling.

Diagnostic test returned P0302 and P0171.
I had him check for vacuum leaks and secure wire connections this AM.

What are suggested next steps in the elimination process? Wires? Battery? --the dreaded engine?

Thanks!

 

had the same thing happen to me, brought it to mazda, it was the intake manifold solenoid

 

Appreciate the quick response!! Can I have my dad replace the intake manifold solenoid?
Can I adjust my settings to receive emails when people respond to my posts?

 

2005, hoe many miles on the engine? I would go ahead and get the compression check. Are you having hard starts when the engine is warm?

 

Thanks, the car has 47000 miles on it. And yes, seems to be havig a harder time starting when the engine is warm (can take 10-15sec or so)

 

Latest update:

ok, to summarize, here's what have been done:

- Battery replaced
- Spark plugs, coils and cables replaced.
- Trottle cleaned.

Seems a bit better, but still, when engine's warm, the RPM will slow down 200 RPM or so every 10 seconds when the ventilation is on.

any other idea anyone?

 

Clogged cat
Low Compression