Car is starting hard, has power turns over but won't start. When it does start it runs rough, then stalls. The shop found a bad ignition wire, they replaced it but it didn't solve the problem. They checked the ignition coils, spark plugs and fuel pump and they were ok. Now the shop wants to do a caustic acid bath to eat the potential engine build-up. Will that solve the problem?

 

Probably not. Sounds expensive. If you really want to clear carbon build up, get a can of seafoam and do it yourself for a couple bucks.

HOW did they 'check the coils'. Alot of dealers mis-diagnose coil failure, a non-dealer doesn't have a chance. Coil testing is 3 Ohm tests PER coil, although dealers will pass anything that isn't a fully open or fully closed circuit, the resistance increases on all 3 points over time, and around .7 ohms they start failing to provide steady power.

However, those symptoms are also symptoms of a dirty MAF, e-shaft sensor not reading right, massively clogged catalytic converter, and clogged air filter.

Try cleaning the MAF (bottle of MAF cleaner is ~$5, takes a minute), checking the air filter, and resetting the e-shaft sensor (key from off to on, don't start, press the brake pedal as fast as you can, enough each time to get resistance, watch the oil pressure gauge, when it sweeps back and forth, you can stop, it has been reset (along with fuel trims, which need some time to stabilize).

If you still have trouble, I'd guess your coils are failing, they just haven't completely failed yet. If you fix all that, and still an issue, check the cat for being clogged.

 

Great Advice, checked the coils found 2 not fully powering. Good thing it fell under warranty. I'll consider the Seafoam for the future. Thank you RIWWP

 

If you have over about 25k miles, replace all four coils, not just the two you found bad!


FYI........if you keep driving with bad coils(or insufficient spark), you can expect a CAT failure down the road, so don't let that happen!

 

I bought a 2004 Mazda Rx8 on 1-17-2010. Went straight to my moms crib like " look at me". When i came back out to start it ..... it wouldn 't... i sat there for bout 20 minutes trying to start the car... wouldn't turn over. I was pissed... Finally it started.. i drove it right back to the dealership and left it there cause they were closed....when i showed back up at the dealership in the morning... they were cool.... they told me that these cars have to shut down a certain way.. But then they also performed some test on the engine and it had a bad compression and they were going to replace the engine for free cause Mazda extended the warranty... the car only had 50, 000 miles on it... they said it would be a week before the parts came in so either i could take the RX-8 back or they could give me a loaner car till it was ready...of coarse i took my RX-8 back and decided just to bring the car back when the parts were in... i took my Rx-8 back to the dealership 2-3-2010 and i just got it back today (2-11-2010)...

i didn't think they were going to replace the engine, but they did.. they also replace my engine mounts for free cause they were bad too...

so if ur RX-8 is having problems try taking it to the Mazda dealership and advise them on the 8 year or 100,000 mile warranty on the motor...


i bought my RX-8 at Suburban Mazda at 37911 Grand River Farmington, MI 48335.. they were very nice to me ... 100% satisfied... hell they put a new engine in my RX-8...