low idle problem...at wits end
#1
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low idle problem...at wits end
I have an 04 rx8 that idles around now 800 rpm maybe a little more. It was idle at 740 and above. I have replaced coils, plugs, wires and cleaned the maf sensor. Fresh oil and air filter. And ran a fuel injector cleaner and today I did an engine flush and cleaned the throttle body but it still idles anywhere from 780-840 rpm. It only has a problem at idle. Does anyone have any clue on what is wrong?
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The compression check is my next step. I want to straighten out the idle problem before installing aftermarket parts on it. But if it comes to the cat then i will change the whole exhaust.
#5
I wonder if your AC or Alternator could be messed up and putting a drag on the engine. If the AC is turned off, but is still engaged due to some failure in the AC clutch, it could put a load on the engine and the ECU wouldn't know to increase the RPM to compensate for the additional load. If the bearings are going out on the Alternator, that could also put a load on the engine. You could take the belt off and make sure all the pulleys spin with little effort. Also you might want to inspect your vacuum lines and take a vacuum gauge to them to see if there are any clogs and/or leaks. It doesn't hurt to disconnect the battery, wait a little bit, reconnect it, and see if the problem persists. Sometimes the ECU just has to be reset. You might get a code scanner and make sure your sensors are giving the ECU realistic values. Your MAF sensor and IAT sensor might be clean, but if there broke or giving false data, who knows how the ECU will respond.
#12
I was looking at another thread (https://www.rx8club.com/series-i-trouble-shooting-95/p0335-eccentric-shaft-position-sensor-circuit-problem-car-will-not-idle-194505/) and some guys were saying the Eccentric Shaft Position Sensor has a tendency to pick up metal junk off the road (since it's magnetic) and throw off your computer. It sounds like it's an easy enough thing to take out, clean, and put back.
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Well I just looked under my car after driving and I had a glowing cat at the O2 sensor so time for a new cat. Also it wasn't just the rpm fluctuation but I also have some bad vibrations and my passenger side floorboard gets pretty hot. So now my next step is to buy a high flow cat and then see how my 8 runs after that.
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Also does any body have recommendations on best exhaust. I have been through the forums but just can't decide. I was thining about buying the kit from sr motorsports, it comes with pulleys, high flow cat, cat back exhaust and cold air intake. Is anybody familiar with sr motorsports?
#20
To not post a new thread...
Mines been idling a TAD rough but since you guys said 750-850 is normal then i guess i'm just being picky, it never drops below 700ish or bounces higher than 900 so i guess i was just expecting it to hold at a steady RPM. I'll still check all the usual issues and for leaks.
Also to note on the cat issue...i having d a rattling noise between 2-3k rpms mainly when im coming to a stop or i'm in neutral or have the clutch in and rev up to 3k. This combined with a p0420/cel and a foul smell after shutdown and hint of gas thru the air vents with the AC on pretty much tells me my cat is shot and i'm assuming that's the noise i'm hearing? So i need recommendations. Go with a catless midpipe or get a high flow one? If i go with a midpipe won't i still be getting a CEL since there will be no cat at all?
Mines been idling a TAD rough but since you guys said 750-850 is normal then i guess i'm just being picky, it never drops below 700ish or bounces higher than 900 so i guess i was just expecting it to hold at a steady RPM. I'll still check all the usual issues and for leaks.
Also to note on the cat issue...i having d a rattling noise between 2-3k rpms mainly when im coming to a stop or i'm in neutral or have the clutch in and rev up to 3k. This combined with a p0420/cel and a foul smell after shutdown and hint of gas thru the air vents with the AC on pretty much tells me my cat is shot and i'm assuming that's the noise i'm hearing? So i need recommendations. Go with a catless midpipe or get a high flow one? If i go with a midpipe won't i still be getting a CEL since there will be no cat at all?
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Update, took it to dealership. They ran a compression check they said compression is fair and I have a bad motor mount and a fan that isn't spinning. They spark plug holes were mildy stripped so plugs were in a little crooked, they fixed the spark plugs. Gotta go back in 2 weeks and get another compression check and if it worse they are going to try and her mazes to cover the cost of an engine replacement. If mazda wont cover it then it's time to scrape up $5000 to pay for the new engine and labor for the swap
#24
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Mazmart, https://www.rx8club.com/mazmart-88/remanufactured-rotary-engines-104255/ the last post in the thread was from 2/27 and listed the price at about $4600 for a basic engine if you give them your core and heres the post about it. I think they can also do more to the engine at a higher price.
The closest I'm doing to basic anymore is $4600 plus core. This would be brand new rotors, housings seals with RE-medy water pump, RE-medy thermostat and RE-medy oil pressure kit. I'm pricier than Mazda at this time due to doing a higher level product.
Paul.
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