Au1976

I have read lots of threads and well not sure where to start.
I bought the car 7 days ago a RX8 2007 231ps
The car started Ok when cold and occasionally when hot after 10 mins
I drove the car flawlessly for 600 miles home
Next day a bit reluctant to start but went eventually the starting got worse and now reluctant to start hot or cold.
When it eventually started it pulled well idled evenly and well worked
It was a bit harder to start today drove to pick up the other half no problems but on the way home it deid at a junction and refused to start untill it was cold and it fired up but will not idle.

When started cold the choke would come on and it ran smoothly until it warm and idle about 850 rpm but now no idle at all just dies there is a lack of hp when it dose get going but dies immediately when I let the revs off.

I did get a engine management light on a few days previous to no idle and it was 0410 secondary air injection fault the air pump definitely runs.

The car did backfired some on the home journey I was winding it out as I do every run.

Previous to the no idle problem the AC would almost stall the engine I put a new battery on it. When the cooling fan came on after the no idle problem it died strait away and refused to start until cold again.

I have reset the KAM and the E sensor
Checked the plugs front rotor plugs looked more coked up the back rotor plugs look right.

I cleaned the E sensor
I cleaned the earth
I took a look at the CAT because the center console under the gear stick gets kinda hot on long runs the outer casing looks like it has been roasted there is like a metal jacket around it which looked corroded and lose.

Oil level is good oil pressure gauge looks good

It sounds like it is running on one rotor but surely the plugs would be wet or coked up lots but they look ok around the electrode.

I checked the coils by pulling the HT lead one at a time to see if there was a spark the first coild had a good spark the others not as strong and one with a weal spark but still sparking. When pulling the HT leads nothing really happened the plugs were getting a spark still but when I pull the the HT lead close to the front the engine almost died.. Hey hang on it still ideled at this point by its self.... it eventually cut out never to idle again!!

The gas stinks of petrol and gives me a really bad head ache

What more to say erm it used one noth of oil in the 1000 ish miles I have driven it it has 92k on the clock and no idea of service history. Strange it would be so bad in such a short period of time..

Aprt from that she smoked a V6 golf and a Vectra SRI pulls like a train or well did

Anyone any tips or clues Please! Thank you!

Loki

iTrader: (1)

I don't fully understand what how you tested the coils, but the short story is coils on these cars get wonky after about 30k miles, so when in doubt, replace.

The other obvious question is thr engine compression. No sense putting time and money into an engine that doesn't hold compression, which is usually indicated by poor warm starts. So. Get it tested, at Mazda, make your decisions from there. Has to be Mazda or a rotary shop, regular compression testers don't work on these cars.

What does the previous owner say about the car's state?

Au1976

The previous owner told me it had been sitting two years and just needed a battery so I put one on it and it started Ok after that but degraded rapidly over the last 5 journeys.
I just check the MOT milage online it hasnt been off the road for two years it clocked up 15k The car passed its MOT just a month ago I guess he knew it was on its way out.
I paid £900 for it

Is there any point in looking through the spark plug holes for scoring ect? problem is its like 500 miles to a Rotary specialist and I doubt very much Mazda in Inverness will have the know how there is no RX8s up here as far as I can tell.

Do these engines just die? or do they fade? Mine just died in the space of 5 miles. It was going strong as in pulling like a steam train and now no grunt at all seems to have a lower pitch coming from it. Still revs to the beep.

Any point in getting cheepo coils just to rule them out? and get better ones if it appears to be better?

The spark plugs look kinda new and shinny on the out side the coils look as if they havent been touched in a while

When I cut the fuel to the engine by pressing the gas pedal to the bottom it cranks about 210 rpm but with fuel I get 330rpm - 360rpm then fires about 370- 380 rpm

I noticed the choke dosent come on or appears not to when cold
Idle was fine and smooth about 850 rpm when warmed up but cold 2000rpm then drops slowly as the engine warms up.

Au1976

I saw a clip on youtube showing that if you pull the spark plug lead of when the engine is running you should see a spark jump from the coil to the lead thus showing if ther is a spark or not.

The first lead from the front had the best spark second lead was poor but still a spark 3 and 4 th ok but not as good as the first.

dannobre

iTrader: (3)

I guess you may have answered your own question.

You need good spark or you will have problems

If you are planning on keeping the car even if you need rebuild then you might as well get new coils and plugs and wires.

If you are going to dump it if it needs a motor then don't bother and get a compression test to tell you how the motor is doing

Au1976

The previous owner told me the car had been sitting two years and just needed a battery and he was selling it for a relative that had had a stroke.

The car passed its MOT one month ago.

I replaced the battery it started fine cold and 3 attempts when warm but sometimes right away

I forgot to say I have the P0410 code intermittently
I always need to press the gas pedal a bit to get her to catch

The car went well pulled hard for like 10 miles switched it off had some tea cake ect, went to take my cousin for a spin didnt really want to start but did we went for a thrash and it preformed perfectly 5 miles turned into my house and it died at the junction not to make an effort to start until it was cold. Since then no idle and dies under 1000rpm

Now if I cut the fuel by pressing the gas pedal down it turns over at 210 with fuel it spins up to 330 and it takes a few attempts to get it spinning faster it catches about 370 and runs.

I noticed the automatic choke doesnt come on when cold it just splutters and dies if I keep the revs about 1000 rpm with the pedal it seems fine.

So anyway it cut out we got it going and on the drive to drop my cousin off it started to lack power not at first but after 3 miles or so

Au1976

Ill buy another motor I love driving this car it really holds the road well.
So even if there is a spark that tells me nothing just there is a spark so weak spark is no good !!

Au1976

There is nowhere close for a compression test like talking 500 miles to the nearest place and they stock rebuilt engines £1350 with a bridge port or £950 standard rebuild and 850 budget rebuild

Loki

iTrader: (1)

I guess start with coils, in that case. See if that does it. There is no Mazda dealer around?

Au1976

No no mazda dealer well there is but only sell cars thanks for taking the time to answer lets hope its as simple as coils

Legot

iTrader: (1)

You could likely get by on just replacing the ignition coils/plugs and the starter. That's probably going to solve most of your problems without resorting to a rebuild quite this early in your rotary journey.

Au1976

I was really hoping someone would say that I hope its that simple for now I knew I would need a new motor but thought I would save up and take a chance driving around the way it is.

I guess its time to start pulling the beast apart, the car is spotless inside and out underneath and on top I refuse to give up on it!!

Gravey

iTrader: (3)

There is a lot of good to the new starter. It cranks faster and can keep a dying engine going on life support for a while longer. But you need the fresh coils/plugs/wires to take advantage of it.

Au1976

I am thinking its a two fold problem or more lol but I charged up the battery and she fired and idled I didnt drive it.

The idle is rough and there is a ticking noise coming from the rear rotor which I guess it the rear rotor failing to fire. There is a fair amount of water/condensation coming from the exhaust lets hope coils fix it!!

Loki

iTrader: (1)

Condensation is fine, but is your coolant level stable? There are different types of ticking, some of it normal. If you want to narrow it down, take a piece of wood, hold one end to your ear and the other to various parts of the engine. When you hit the one that's ticking, you'll know.


While you're doing the coils, change the spark plugs and leads too. You said some were crusty. Fresh start

After you charged up the battery, did it start easily? Have you tested the battery? If it has a dead cell, that wil definitely make starting difficult.

Au1976

Coolant levels are ok I pulled the leading plugs and the front rotor apex seals look ok stick out abot 1.5mm ish the back rotor however two seals look good but one of them looks gunked up I think... or its a lump of coke.. What I am thinking is the 3 poor coils were not burning the fuel efficiently and one of the seals got coked up with oil and unburnt fuel and it got stuck and never came out again.. question is how do I free it up Seafoam, coils, leads, plugs and starter motor.

Loki

iTrader: (1)

Sounds logical. I've never tried this, so this is all experimental, but if you can hit the gunked up apex seal with Seafoam directly through the spark plug hole, then let it sit 20 minutes, then run the engine, then hit it again, etc., you might start to see improvement.

Don't try to clean it with anything mechanical. Also heavily premix 2-stroke oil in your fuel while you're doing this.

Au1976

I just read an article on here about using automatic transmission oil let it sit 24 hour clear her out then new plugs and take it for a few high speed/rev runs..

I have really good (expensive) two stroke for bike racing and cust Rc build I done those engines were air cooled and ran at 28,000 rpm I modded chainsaw engines for the buggies. The oil is based on castor oil. It has a high burning point and very good lubrication what would I mix it too? 100:1?
I guess the last owner never kept up with oil service. The rear rotor definitely look more oily than the front it looked more like carbon coke. The rear plugs had the right colour to them and not oiled up which I find strange.

I think the alternator is weak and in combination with week coils this caused the unburnt fuel to foul the rear rotor and the cat the heat shield is almost toast! Possibly the extra heat kept the rear plugs looking the right colour and the extra residual heat from the cat and baked depleted oil on to the Apex seal maybe it stopped near the oil injector or got flooded and left for some time hot ish..
Who knows but atleast there might be some light yet I hope so I want to drive until I can afford a rebuild bridge port, turbo and then Ill just drive it to the track and back a nice day out!

Ill try this at the weekend and get back might help others I guess others already know lol !

Au1976

I found this thread
https://www.rx8club.com/series-i-tec...ne-atf-170689/

Au1976

It could be more efficient and less ATF in my engine eating seals!
Turn the engine over with a T bar until the gunked Apex seal is just below the spark plug hole and squrit in ATF with a syringe and small tube so it really soaks into the gunk! and just keep dribbling it over the seal.
I cleaned the plugs with either the deposits fell off instantly but not sure about pure either in a engine boom!! a drip might not hurt naa scrap that too explosive

New Yorker

If you don't have the time and money to become one yourself, I think you really do need to find a competent rotary mechanic. I'm serious. Or else plan on wasting a lot of time and money trying different solutions that don't solve the problem. Who knows? Maybe you'll get lucky and stumble across the solution. But if it were me, I'd try harder to find a well-trained rotary mechanic. Hey, if it was easy, everyone could do it. Good luck.

Au1976

New Yorker,
I wouldnt have said its that complicated to fix to be honest I am just trying to squeeze a few more miles.

ill buy a modded reconditioned engine for it whack on a supercharger and call it mine.

I have been around engines all my life just not rotary but thats why I bought it to learn about them. Its a lot less complicated than my audi allroad and there is loads of room to work on these motors its just a poa 100 miles later.