Hey, I have this problem with the engine, it's something new ( 1 month maybe ).

Every time I shift to neutral I ( moving or in place ) the car should come back to around 750 RMP, but instead she goes down to 500, but only for a little, and then she adjusts back to 750. It wouldn't bother me if she wouldn't choke a little, but when it goes to 500 the engine starts shaking a little like I would slowly release the clutch in gear without accelerating.

Take a look at the video please, the final rev shows clearly how she goes to 500 then slowly adjusts back to 750.

https://www.youtube.com/watch?v=EE_4hbo ... e=youtu.be

Sometimes it takes a little longer until it readjusts, especially when moving or in traffic, sometimes she doesn't even have time to readjust because I have to move again e.g after a short red light.

I really don't think adjusting the throttle or rev or what it's called will help, she will still probably under-rev after I throttle her and then adjust back to what it should be.

So ? Damaged sensor ? Clogged injectors ? Blocked hydraulic lifters ?

I'd blame it on the injectors right ? I'm not sure yet though if she does it when the fuel tank is emptier.

For example, another issue with her would be this :

When 1/2 tank is full, I get no problems hitting the throttle, 1st, 2nd, 3rd gear up to 5000-6000 rpm, goes really nice.

But when the yellow light is on and tank is almost empty 2nd gear shift will almost always hesitate. I clutch, shift, release the clutch, and when I hit the throttle, the car enters engine break for about 1-2 seconds, and only after starts accelerating again suddenly.

At first I though it was the clutch not getting completely released, but that would cause problems even at slow accelerations, and as I was saying if the tank is full, no hesitations

Any ideas ?

Well the idle problem looks to be classic symptoms of either a leaky intake pipe, or incorrectly set idle speed. Check the rubber hose from the throttle body to the MAF sensor for splits or cracks, especially in the ribbed section. Cheap fix is to wrap it in PVC tape to see if that cures it.

Next I would look at the idle mixture adjustment (despite what you say ) - get the engine warm, then bridge TEN and GND in the diagnostic port with a paperclip or a bit of wire, and I'll bet money that the revs drop or possibly even stall. In which case, turn the idle adjustment screw on the throttle body (I can never remember which direction, I want to say anti-clockwise but I'm not sure) until it sits at 750rpm, then remove the jumper wire (or paper clip!).

As for the hesitation on low fuel, easy fix is to put more fuel in

Check the condition of the spark plugs and HT leads too, always worth keeping them in top shape

Hugh u da' man

Forgot to specify it's a V6

I know you have the thread " engine stalling under braking" but mine's not really stalling under break, not sure though, I probably always keep my foot on the break when stopped, but from what I see, the revs drop also when moving in idle, and only when I stop do they actually rise back.

There's a guide in that thread for adjusting the idle.

I'll check the idle adjustment this weekend. Hope I don't mess things up lol.

I'm not the best mechanic

can you be a little more specific with the " rubber hose from the throttle body to the MAF sensor " ? Is it the one where the throttle pedal let's air come in through ? Near the air filter ?

I recently had some cooling agent leaks, really bad and messy, I could smell the boiled liquid inside the car for a couple of weeks. No choice but to put some of that liquid that fills the holes. I know it's not good but no other choice.

It kinda messed things up, alarm won't activate the yellow signal lights if the signals are on idle, but it will if I signal left or right... I can still hear the tick tock though. Need an electrician. It's not the fuses, I checked them all twice

Also, more fuel is bad for my pocket 21 liters in and I only managed to get 200km from her mixt consumption, actually more like 35% city driving, rarely do I go over 2500 3000 rpm

Yeah you're describing EXACTLY what happens when the idle adjustment is too low it's not necessarly under braking, it's just when the engine is not under load - say you're pulling up to traffic lights - stick the clutch in (hopefully the brake too) and it drops to below idle, then stays there until the car has stopped.

Adjusting the idle is dead simple - if the revs dip when you turn the screw, turn the screw the other way and they should come back up. If the engine stalls when you install the jumper wire - turn the screw two full turns, then restart the engine (jumper wire still in place) and continue. If it does it again, turn it the other way

Big rubber intake hose - can't really miss it, it's big and it's rubber, has a ribbed section, sits between the throttle body and MAF sensor. Behind the air filter you have the MAF sensor (wires coming out of it), which is on a BIG RUBBER HOSE, and then the throttle body - it's that hose you should check for leaks.

Sounds like the coolant leak has damaged a relay of some sort - without the car in front of me I can't really help you there!

I have the same problem with my Z5..
Checked the idle in service mode, 750-780 ok..
I think it's the system that is carrying for low revs that's faulty, maybe clogged..
Maybe it's the throttle,it could get dirty and sticky you know.. from engine oil vapors and dust that is sucked trough the air filter, sometimes the exhaust gases return trough the intake valves and make deposits..
How tight is your throttle cable? too tight or loosened?
If i have free time this weekend i will open and clean them with acetone, try what i've done
and then will doubt any other systems..
When you leave the pedal alone and revs fall down to 750 then ECU leave the responsibility for the revs to the "stepper motor" (that's what we call it, i don't know the word in English)
Also, the problem with 1-2second hesitation may be caused by displaced TPS sensor..
Had that on my car too.. fixed.
I know quick way to do it, but it's for my 1.5, i doubt that for 2.0 will be different thou..
If you want i can explain it to you.. ( but you do it on your own risk!!!) not that anything will get damaged from this..
I think HughieW knows it too..
If i were you i would try to adjust TPS first, then idle in "safe mode"
Then try what's happening and if it does it again,you probably have very dirty low rev system and it has to be cleaned..
They sell some sprays that do the work without disassembling things but they don't clean it 100%..
Hope you sort it out!

Whoa that's a lot to digest there xD I need some help over FB or Skype I'll PM you for a Skype ID or something.

She just under-revs for a little, she ultimately figures it out that the revs are too low, and in the end ( for a long idle rev ) she stays at 750, which is the normal. I noticed that cold starts ( winter ) the car used to go at about 1500 before heating up, now she starts a bit under that, depends on how cold it's outside though.

I'll try to adjust the revs this weekend as I said, and I'll ask you a little more about what you said

Thing is ... shouldn't the sensor fault light up some error codes ? I recently did the diagnostic on her with a jumper and a 12v light, and only one big flash, no error codes. I unplugged something and she did read an error, to make sure it worked. Then plugged it back in, and no error codes again.

In the end imna have to fix everything by my own this summer. Mechanics here are really ... dumb and uninterested. And for someone to take time to actually study the engine and car it would cost me too much. Prolly gonna just do it with my dad this summer with a forum thread and help from you guys She also has a ticking sound in the engine, a mechanic opened the engine up but couldn't figure out for sure what it is.

Also ... can I do something like this to the 323f V6 ?

https://www.youtube.com/watch?v=HT71uhnNYjg

I do get a ticking sound usually on startups, but sometimes it persists, and can be always head if you get your ear closer to the engine.

It's either that, or some pressure disk/spring that's between a split gear ( long side ) that turns the camshafts ( I think it's called ).

I know the code exactly, should be in a FB conversation with Hughie, but I never had the time to fix it because the Mazda dealer near me recently went out of business . They had some problems with a dealer and they got sued... blahblah.

Myeah ... weather was against me.

It was really cold and snowing a little I couldn't get to try and fix it ... not quite cool working in a city backstreet lel.

maZZda was really nice and explained everything step by step on Skype. Thanks for that man !

I'll prolly postpone it 'till after my exams and just do it home, I'll also post a video tutorial if it fixes my issue

Ok, I did it.

I reset the idle revs, and also fixed the TPS as maZZda described in the Skype conversation.

Though I did encounter some problems :

The problem with the revs seems to have solved herself since the first time I posted here, but the revs were slightly a bit over 750.

As I pinned the TEN and GND, the revs dropped a little, just a bit over 500.

I turned the pin and tried to adjust it just to 750 but it was pretty hard to get there.

It was either a little bit over ( let's call it 760 ) , or a little bit under ( let's call it 740 )

Now if I went a little bit over, then rev the engine, it would drop back to exactly 760, and stay there.

But if I went a little bit under, and rev the engine, it would do the thingy, dropping to almost 500 first and then coming back to 740.

Trying to adjust it RIGHT at 750 would make the needle oscillate a lot, between 760-750-740, and after revving the engine, it wouldn't drop back just back to 750, but a bit under.

Also, with the GND and TEN pin in, I could get it to stay just at 750 sometimes, but removing the TEN and GND would increase the revs a bit , to 760.


So I decided to let it run at 760. This was only yesterday, so I'll see how it keeps up.

What do you guys think, is it ok ?





I also adjusted the TPS. Just as described by maZZda ( thanks man ) , after turning a little, the fan started blowing, so I knew exactly where to adjust.

I'm not sure if it helped yet, but the fuel needle was indicating a little more fuel after lol ( and I'm sure of that, but it;s just computer stuff ).

The bolt from the bottom side of the TPS was harder to get at, and I hope I tightened it back well too. I'll recheck everything next weekend though.


So do you guys think it's ok with not being able to get the idle just at 750 ?

Good work, yep that sounds fine to me - the rev gauge isn't that accurate anyway! Its probably just reading a smidge high at idle, wouldn't worry about it!

Here's what i did:
-Cleaned the whole intake: hose,maf,throtlle body,tps adjusted,solenoid valve for idle cleaned..
-Changed air filter
-Cheked the revs in service mode, made them 770 somewhere..
For now (2-3 days) there's no problem for revs..
That what concernes me is when i rotate the adjusting bolt in throtlle body there's a moment (whole turn and a half) that the revs stays the same and i can't tune it very properly..
Can i just remove the bolt so i can blow out any sludge inside it's chanel? I cleaned the TB with acetone and inside that litlle hole is still dark and with black soot..
I thought i can cleaned it with pressure from my air compressor..
Will it be possible to remove it,cleane it, and put it back together without making something wrong?
Is it only screw or it holds something inside (i doubt it but it's best to ask)
And i know after that i would have ro adjust low revs again.. i will remember the turns it needs to come out so i can put it again at almoust the same positione it was..
So can someone tell me is it ok to unscrew it or no?

I'll clean it in the summer too just the way you did it.

The thing with the idle pin not responding accordingly happened to me as well.

When I turned the pin a bit each time, the first movements wouldn't respond. It had a bit of delay also. So basically only a quarter turn would respond, and it sometimes took full turns to get it move 250 units. Like I could easily hit 500, 750, 1000, but everything inbetween was harder to get.

Just try and tighten your hand in there really strong so that you have lots of control and see if you can move the pin only a very tiny little bit. That helped with me, it's actually pretty sensitive but you need patience.

So then I guess the pin adjusts the idle digitally ? If it's manual, then why do I have to short TEN and GND and put it in service mode, can't I just adjust the idle whenever I want ?
Will it not remember it the next time I start the engine, or will it conflict with the ECU and the quantity of fuel that goes in through the injectors ?

I'll make a complete guide on adjusting the TPS and revs idle, search engine optimized, as I'm studying this stuff. I hope I'll make it easy for everyone even when searching on Google to find my post here

As for cleaning the idle pin ... I'm not all that sure but I'll see this summer with I have time and a place to do it. Hugh might be able to answer this one though

Also reading this post ( link below ) about the Type R down on power made me think I should try and clean the MAF sensor.

viewtopic.php?f=3&t=58194

The filter was pretty dirty when I bought the car. I changed it with a new one, but haven't cleaned the MAF.

3 rainbowy Questions :

1. Is this the MAF sensor ? ( green arrow )

2. What's there ? There is a pin that you can adjust right on that black rubber part, but I didn't notice any change. Does it do something ? ( yellow arrow )

3. I suppose this a vacuum ? I unplugged it, a little white smoke would come out rythmically from cylinder head, just like on a steam powered choochoo train ( it was pretty damn cold outside though, and the smoke could be barely seen ) The tube was good, but that part right where the arrow is pointing was completely clogged. I could not blow through it. I tried to clear it a little, and it's a bit better now. If I put my finger there when the engine is running it would create a small vacuum, but it's really light though. Is that good or bad ?

1st - yes, that's your mass air flow meter
2nd - pass (i have 1,5 z5 engine) someone who has 2,0L to tell
3rd - this is PCV valve, it's made so the intake can suck oil vapors from engine for ecology..
It work/open only when there's vacuum from the intake, otherwise it has spring inside and closes it self..

I understand.

Sunday I'll be leaving for University, and I'll drive a little bit more.

I hope I'll see a little improvement from what I've done so far.

can I hear the timing belt tensioner rattling a bit? when I turn my speakers up to listen I can hear a slight rattle that speeds up and slows with the engine speed. that would cause timing to be out, and ecu trying to correct it recovers the revs when idling