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I've read a lot of posts / threads on this, and have an idea of what I should do, but I just want to express my symptoms so I can make more sense of the situation. Car is an 04' with 11k, and the things I've done thus far are plugs, wires, coils, air box wall removal, K&N filter, and Turboxs catback. Before I installed my catback I noticed my idle would sit around 750-800, and cause a little vibration during idle. Idle would stay rather steady though.
Tonight, after beating on my car and playing w my new exhaust, I filled it up with gas, came home, and before I shut it off, let it sit and idle for a minute. Once the car calmed down and dipped below 1000rpm, it hit my "normal" idle, which was 750-850 as stated before. Then I saw it drop to the lowest it's been, being about 600, and just when it felt like it was going to stall, it shot back up to 1k, then back to normal and was steady.
I don't believe this is a compression issue. My car always fires up immediately especially when hot, along with pulling very strong and hitting high RPMs no problem. I've think it may be related to the K&N filter combined with the fact that I removed the stock airbox walls, or fins, or baffles, i.e. Perhaps the car is sucking in too much air at different turbulence now and messing with my MAF?
My MAF did get hit w some oil recently, as my first oil changed I poured it in too quick. Oil got in the intake, but I Cleaned it out and sprayed the MAF down. I have NOT reset my car or it's computer yet after any of these mods.
What do you guys think would be the best course of action? Should I be concerned, or does this sound like a basic MAF issue? Should I try resetting the computer first? OR just going back to paper filter, then resetting it?
If it's not stalling or constantly jumping all over the place, leave it. Don't look for problems that don't exist
I agree, and for the past few weeks I got used to the slight vibration and was content with the idle not fluctuating. But like I said, after tonight and giving it a good run, I did't like how far it dipped at one point. I guess I'll go back to a new paper filter and clean the maf again.
What about the ESS? Do you guys think it's worth it to clean it? Do I have to remove this thing or can I just wipe it down / spray it from underneath or above the car
So I decided to take a look after I cleaned all the oil out about 2 weeks ago. I popped the two clips on the airbox and was able to use the half inch of leeway to shine a light in there. Their was a tiny amount of oil sitting above the filter, and running up into the first screen. I pulled the maf and it appeared clean, as pictured. Right below where the MAF sits, you can see a small puddle of oil. Will clean it all out again tomorrow. This time, the oil did not make it to the throttle body. I removed the side box before the TB attached with one hose clap, and saw the accordion tube was still clean. I'm assuming even if the MAF appears clean, this is likely the cause of my issues?
Image is blurry but if you look directly above the filter, you will see the little oil puddle that caught the flash reflection
Clean that ess, it's easy and can't hurt. I developed idle fluctuations from a weak battery, doesn't sound like that's your issue but it helped with mine. Another big help is to get a long tube funnel that goes past the hose to the accordion tube. Stops the oil from leaking into the air box. Get to that tb as well and clean it out, yet another thing that smoothed my idle out. Might be you find more accumulated oil. If the k&n filter has oil saturated in it I learned a method to clean it from another thread. I was to cheap to get the kit so I used a liter of seltzer water and scoop of oxy clean in a baking dish. Got all sorts of garbage out of the filter. Let it dry and oil it up. Good to go. Did you try resetting the Ecu by pulling the battery for several minutes? The ecu will have to sort out its long term fuel trims which would be good given your recent mods. Good luck!
Put the airbox baffles back in, they're there to smooth out the airflow for the MAF. There is an updated oil fill neck available for the 04-05s that decreases the likelyhood of oil ending up in the intake, it may be worth getting. It's about 250 CDN from Mazda though... so.. try the baffles first
Are the 2 mesh screens immediately before the MAF still there as well?
Put the airbox baffles back in, they're there to smooth out the airflow for the MAF. There is an updated oil fill neck available for the 04-05s that decreases the likelyhood of oil ending up in the intake, it may be worth getting. It's about 250 CDN from Mazda though... so.. try the baffles first
Are the 2 mesh screens immediately before the MAF still there as well?
Yes, I left the two screens in there. Funny thing is when I got the car a month and a half ago, I had zero issues, so clearly it's something I changed. I was eager to work on the car today, but of course it's snowing in NY.
I was going to try cleaning the intake again and then the ESS. Then I was going to do a battery reset and let it run a few cycles. Should I try this first? I have yet to reset the computer at all after doing any of these mods, and to be honest, after the catback install, that's when the idle dipped the lowest. Perhaps the fuel trim levels need to relearn because it's flowing a bit better now?
You could try cleaning the ess and resetting the NVRAM (20 brake pedal stomp), re-clean the maf, etc.
But I haven't seen anything about the neutral switch. Check it to make sure that it's connected properly.
So today, despite the 10 degree temp I got outside and did what I could. Took apart the intake, and saw the oil was very minimal. Cleaned it out, cleaned MAF, fired right up, no issues. Once it warmed up the idle held steady.
The issue only occurs after I rev the car. Once it was warm I gave it a few good high revs, and once it dropped down, it hit around 1k rpm, then a little lower, then about like 700 the lowest, then back up to a steady 800. Didn't really feel like it was going to stall, and once the rpm hit the normal idle figure, it stayed there. No shooting back and up and down.
Going to clean the ESS when there isn't ice on the ground and do the reset. Maybe it's just because my intake setup. But it definitely only occurs after I rev it, and then it'll drop just under normal idle and roll back up.
Is your A/C on (I know it's cold, but A/C is still used when the cabin blower is set to the "windows" setting fully or partially)? Because that introduces an RPM drop whenever the compressor cycles on.
Is your A/C on (I know it's cold, but A/C is still used when the cabin blower is set to the "windows" setting fully or partially)? Because that introduces an RPM drop whenever the compressor cycles on.
No I tested with A/C on zero, and at the default setting (bottom bottom with the airflow arrow flowing through the car), and with the other setting as upper body / foot warmer. I should probably stop wasting time and do the 20 pedal reset lol. I've read that it smooth out some people's idles due to the ESS relearning itself. Like I said, I've changed the intake a bit, the exhaust, coils, plugs, and wires with no reset. The only reason I didn't do the reset today is because I figured it should be driven right after, to "relearn" what it's going through. Is it cool to reset the NVRAM through that procedure and just let it idle?
I know with my 350z I would reset the battery after every mod, and then beat on it right after I hooked it back up. They claimed this way the freshly reset ECU would "adapt" to the new style of driving along with the new mods and better flow, etc. I guess this is still my mentality with the Rx8. Reset the ECU, then beat on it so it adapts to that form of driving.
Got to finally drive the car today since most of the snow is out of the way and noticed a difference. Yesterday, I cleaned the intake again, along with the MAF, and tightened all hoses. Also got under my car at night on the ice and snow and tried cleaning my ESS. Was a very tight squeeze so I sprayed it liberally with cleaner and ragged it where I could. Did the 20 stomp reset and let it idle for 10min.
Went to drive it this morning and everything was smooth and responsive, and once it finally warmed up I tested my idle. Pulled up to a stop light and it definitely seemed more steady, and maybe even a little higher.
Anyway, the car felt like it was pulling much better after the nvram / 20 brake stomp reset. Perhaps this is because I never reset anything after intake, exhaust, coils, plugs, wires, etc. I went to punch it in 2nd gear at 5k rpm and the rear end actually kicked out a little on me. Anyway, it brought a smile to my face and I realized as long as the car is pulling hard, there's no CEL, and it's not stalling, I'm content.
So, gents. After doing what I wrote above, I was driving today and noticed I was basically back at square one. I would drive the car hard, and once it was warmed up and I let the idle settle, I'd get a few occasional dips and it felt a little extra rough - not misfire rough, and never stalled, but the vibrations were back.
Long story short, I decided to get the car on the lift (perks of working at a dealership) and clean the ESS the right way. Thought it would be a pain to remove, so I originally planned on just wiping it down again. Turns out there's really only one correct way to do this, and its to remove the whole ESS. Once the car was in the air I realized with a swivel ratchet and extension it was very easy to get too. Connector was also extremely easy to pop off. Took off sensor no problem.
I liberally sprayed the ESS (crankshaft sensor for Rx8s) with electrical cleaner. Used a paper towel on some stubborn spots. This is what I failed to do the first time - remove it and clean it right. First time I "cleaned" it, I simply slide under the car and sprayed half of it down. This won't work unless you remove it, because one side is hard to aim at / get to.
Anyway, I got it fully clean. Attached are the pics. Afterward I popped the hood, and secured my MAF - one screw was stripped, so I swapped them and tightened it, and realized one vaccuum line into the intake had some plan. I greased the nipples and put them back in, and made sure everything was tight.
My idle finally seems smoother. Definitely noticed less vibrations at idle now, along with dips. I drove it hard and warmed it up thoroughly, and did the same test I did before. Revved it once warmed, then let it drop and watched what happens. It definitely seems smoother now that I did it right, and hopefully it stays that way.
That makes sense, even small vacuum leaks will affect idle atability. The car only draws 5 grams of air per second so small leaks make a big difference. Glad you got it sorted.
now do yourself a favor, and pull the room fuse or a battery cable then hit the brake.
after that start the car and dont touch a thing until the cooling fans come on..
the car will idle better after that.
beers
So you're saying pretty much do the KAM reset? That resets the fuel trims right? I wanted to do this, but I've read about people having it stall out or ride like **** while it "relearns". My battery and everything else is good though so hopefully I won't have an issue, and I wanted to reset my fuel level profiles.
I can just disconnect one terminal, hit the brake to kill the battery, and then fire it back up and let it idle for a while?
Nevermind, I figured it out. Unplugged my battery for 5-10min and did a few brake taps. Plugged it back in, turned ignition on, did 20 stomp reset, and then fired it up. Moved my steering wheel back and forth, light went off. Let car idle for 20min or so, and had zero issues whatsoever with stalling or roughness. Car drives fine, can't say I see much of an improvement since it was already OK, but at least everything is reset and fresh for all the changes I made.
Found a solution my fluctuating idle issue (if anyone views this in the future)
I originally bought my car at 10k miles w zero issues. After trying to unlock a few extra hp (the cheap way) I decided to remove the two walls in my airbox and also add a K&N filter. In time, I noticed that once my car warmed up and I revved it, as soon as it dropped down to idle it would fluctuate between 600-800rpm. Never stalled, and not the end of the world, but it did bother me.
I wound up cleaning my MAF, changed plugs, wires, coils, pulled and cleaned ESS, and reset NVRAM and kam. Car ran well, but eventually after warming it up a decent amount the issue would come back.
Instead of playing with the stock airbox again I decided to buy an AEM cold air. I just finished installing it, and noticed my idle is very smooth again. That being said, those who predicted that the combination of the K&N and removed baffles would mess with the MAF were correct. Apparently these MAFs are indeed very sensitive and even the slightest miscalculation or wrong flow of air can throw it off. Thankfully, the AEM fixed that issue and gave me the extra little boost and sound I wanted.
01-06-2017, 07:52 PM
