Have you vacuum tested the engine while hot? Have you checked all the vacuum routing on the turbo kit? Do you have the Greddy "fixes" done? Did you check the purge valve? Who tuned it? Have you done a vacuum test on the engine or a compression test? Just because it was rebuilt recently doesn't mean it was done right.

 

Do you have access to the AP map ?

Also : why do you push clutch in and coast at those speeds anyway ?

 

It was rebuilt by speed1 in Allentown PA, They checkd the tune when they rebuilt it and said that it was perfect. I haven't done a real vacuum test, but the vacuum on my boost gauge reads -9 at idle, which is really low for vacuum, but i don't trust that gauge really. It's a crappy ebay digital gauge that isn't the most reliable.

As for the purge valve, no I havn't checked it. You think that could be causing the problem?

As for the data logs and the map, I haven't taken a look let, but will upload when I get a chance. The o2 sensor isn't going to be replaced until sometime next week.

 

It almost feels like the car doesn't want to relearn the fuel trims, or it's stuck in open loop or something. I get a little bit of idle hunt when i'm just sitting still too, but it comes and goes.

 

Resetting all the idle maps to 900 may solve it ... if you have access to the map .


BTW : It's a bad driving practice to coast out of drive

 

Yeah i know, I don't do it too often, but If I really need to come to a stop quick or something, I tend to just pop it into neutral and hit the brakes.

I saw on another thread that changing the ide maps to 900 might fix it, and I thought about giving it a shot

 

Huh I drop it to thrid when I need to do anything fast. Slow or go. You still never reported what your fuel trims are. 9PSI of vac is pretty good. 9" of vac is bad. which one is your gauge showing?

 

Folks, I'm new to the forum and not all that mechanically inclined so bear with me on this question. I've got a 2007 and in VERY cold (like -20degree) conditions I have problems maintaining idle. The car starts fine, but once I start taking my foot off the clutch, RPMs drop quickly and the car stalls. If I carefully release the clutch slowly over say 10 seconds, I can hear something starting to move (rotate?) at increasing speed and after another 10 seconds or so, that noise goes away and the car will idle just fine with clutch completely released in neutral. I've tried just running the car with clutch in and letting it warm up for five minutes before normally releasing the clutch, but that doesn't seem to help. I had thought maybe it was time for a fluid change, but my transmission fluid is only a couple of years old. Oil is always changed on schedule. This isn't causing me any real grief since I now know how to work around this, but I am curious as to what is going on - any info is appreciated.

 

Clean your MAF, reset your fuel trims, let the car idle warm and then for another 5-10 minutes. See if the problem persists.

 

Thanks for the advice - although I'm not sure how this ties to my problem it sounds like a good idea nonetheless. Unfortunately I won't know if this works for another 7 months!

 

The MAF is what the ECU uses to determine the baseline information for how much air the engine is consuming, so it knows how much fuel to inject. If the MAF is reporting something inaccurately (too high OR too low), then the fueling will also be off. At idle the airflow is so low that even a slight disruption in either direction can have a profound impact on the ability for the car to idle.

Since you are saying it's only in deep cold, this suggests to me that the MAF itself is having trouble with the cold, either condensation, freezing, or something like that, and only once the engine bay heats up to more reasonable temps does the problem go away. The MAF should be able to handle super cold temps if it's clean, so you might have something on it that isn't clean, and perhaps that substance is what is freezing over.

 

Hey everyone, new to the forum.

Just purchased a 2005 RX8 base 6-speed. And it came with no catalytic converter. I got one put on, and shortly after that, my car has problems idling and even trying to die on me in 4th gear going 40 or 50. I cleaned the MAF, seemed okay for a few drives and then started acting up again. Mazda has identified a VDI solenoid problem (dont know what that is but its been a problem on it since ive bought it, wouldnt it have acted up before hand?) anyway, im looking for a solution to my specific problem. Im happy to provide some more information if its needed. I just dont want to pay a dealership thousands of dollars for something that might can be fixed relatively easily.

Thanks!

 

VDI won't be an issue with idle.....it is more of high RPM intake resonance thing..

I would remove the CAT and see how it runs......usually if a problem starts after you **** with something ...it is something that you did whilst you were pissing with said thing

 

You see, I live in the state of texas, where it is illegal (unfortunately) to not have a CAT on the car. I also just gave it one good test run blowing every gear out and when I returned, my coolant chamber was smoking out and the fans blew on hella high for a solid 5 minutes. Any other thoughts on what this all could be?? I read somewhere about having to adjust the Computers values once you put a cat on, but I am unfamiliar with how to do this. Also, the smoking now has me a little worried. The temp readings inside were all within normal parameters though.

Any thoughts?

 

JC, let the car cool down. then pop your coolant cap and start the car. Then watch it as the car warms up. IF it starts boiling out then you need a coolant pressure test.

Dan is saying to remove the cat just to test if that's the problem. you can remove it in your driveway legaly.

 

Can I get directed to a DIY on how to remove the CAT? Im pretty car illiterate, but need to learn as much as I can about maintaining this vehicle. Much help!

 

I thought you might have swaped it. do you still have the other one? If not I wouldn't do it. They are pretty loud without it.

Try running it with the coolant cap off and see if the coolant boils.

Where are you in texas?

 

You see, I bought the car a few days ago. I thought I bought a "street legal" car. But when I took it to the dealership to have everything checked out, I was surprised to find that there was no Cat on it to begin with. It was just a straight pipe. I took it to a garage and got a pretty nice aftermarket cat put on. Since then these problems arose. And I will try the coolant cap thing tomorrow in the day when its not so damn "tornadoey" out. Screw this Dallas weather rn...

 

it was jsut straight pipe, that is crazy. did it show any codes? did the sound change much? Most people put on a resonated mid pipe and it doesn't make the car much louder than stock.

 

Private sale? You should have got a compression test done before buying it.

 

When I got the car diagnosed, two codes popped up. I do believe one was for the missing CAT but no one ever gave me a straight answer until I took it to the dealership.

Those codes were:

P2097
P0171

Now, to also add. When I cleaned the MAF today, it somehow turned off my check engine light, which at this point I thought has been on because of the VDI solenoid problem. But now its gone. Which really leaves me in a dead point. I dont know what to do, the car rough idles, the coolant chamber smokes, and it doesnt seem to be as smooth of a drive as when I tested it last week.

 

Not a private sale, through a so called "reputable dealership" but I have filed complaints with them as they with held some of this information about the CAT and what not. They knew it did not have one and sold it to me anyway. 85k miles. Seemed fine.

 

both of those codes are saying bad AFR's. I can't say I've seen those issues before, btu it seams to point to a bad 02 sensor just from seeing them. One is lean and one is rich.

https://www.rx8club.com/series-i-tec...n-guide-26291/

 

if it was a dealership and less than 3 days you should be able to return it with no problem. I beleive you have 72 hours to back out of a contract in texas.

in fact I dont' think they can legaly sell a car that is not emissions legal and they should be responsable for makign the car emissions legal. Which includes no emissions lights and a proper cat. Not an aftermarket cat. Did you get a mazda Cat?

 

It was about 10 days ago. Pretty much stuck with the thing. But I love it! and I feel like most of these issues can be fixed pretty easily. Its just finding the right person to diagnose and tell me what to do. If you know of any reputable DFW rotary mechanics, please provide some info!

And as far as those codes, the light is now off. And How could I go forward with fixing these issues?