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Mazda 6 running/starting problem

22K views 19 replies 6 participants last post by  hyperbole 
#1 ·
Hi people,

I have i big problem, I have mazda 6 (2004) 2.0 diezel 120HP.
Some time ago my car suddenly, while it was working in neutral gear, it shut off. I tried to start, the car started, but immediately shut off again (like it was without gas). Tried again, again the same, start and immediately shut off. Then, I start again, I put the gas treadle and I started to drive the car. After 10 minutes driving, the problem was gone, the car was working fine.
A couple of days later, the same problem, for example, I'm driving my car for 20 minutes into the city, I came to the traffic lite, I stopped, put the car into a neutral gear, and my car shut off again. The same problem again! And if I start it, and put some gas treadle the car will start moving. So, the problem is not all the time, just from time to time, very strange!!!
It is very difficult to me to explain, but I hope someone understand me.
I change the gas filter, oil filter, air filter...nothing, the problem is here.
I also put some WURTH diezel additiv in my car, but nothing.
In my country there is no Mazda service, so I went in mechanical shops that are working with a lots of cars.
I went to 3 different mechanical shops, they put it on a computer, and there is no problem diagnosed with the car.
I put out all the gas from the tank, cleaned the installation from the tank to the gas filter, but the problem is still here.

Can anyone help me?
 
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#3 · (Edited)
Dave thanks for your answer,

I don't know if you understand my problem, but if you did, thanks again.

The problem is not appearing every time when I stop the car, for example now I'm driving the car for two days, without problem.

I wanted to record the problem with my phone, but as I said, now for two days, no problems. I wanted to recorded with my phone, to be more clear to you people.

Where I can see, I mean can I see this same problem on youtube, or if you have some records to show me?
Or how can I test this SCV? Is there any procedure for testing this valve?

Thanks again
 
#4 ·
Hi Drozer, got your message, the problem with the SCV is that it wears slightly the it can't control the fuel pressure and you have intermitant running problems that won't show a code, Mazda have since changed the design on the newer models!
You can download the diesel manual from the link below, you want 1744-1E-02D
Index of /~benjsc/download/Mazda6

You can then look up how to test the valve, but if it's worn the test might not show anything.


Dave
 
#5 ·
Dave thanks for your replay...

But is very confusing for me, because now when I'm driving the car for several days, there is no problem.
Can I just remove the SCV, clean it, and return back in?
Can it be the injectors problem?
BTW, I cannot find the SCV in the manual that you posted, or is it called otherwise?

Thanks
 
#6 ·
There is'nt anything you can do with the SCV, as such it's a non serviceable item.
The file can be found in the Diesel section under "fuel and emission control systems" (MZD-CD RF TURBO)
The injectors are very reliable and i've not come across any that have failed or given any trouble, the only thing you could check is the calibration but you'll need access to the Mazda software to do this.

Dave
 
#7 ·
Hi Dave,

These previous days I have visited mechanical service.
They put one device into the place where you connect the computer, and I drove the car with this device on. The device serves to record all thing during driving.

I drove the car 3 days (city driving), no problems. Today, I traveled to another city, around 120 km and when I arrived there the problem occurs again. After that I went again to the mechanical service, and they pull out the device, connect to PC.
On the device error messages were written:
1. Manifold absolute pressure sensor (MAP sensor)
2. Camshaft position (CMP) sensor

What do you think about this? What is your opinion?
How these sensors are connected with my problem?

Thanks in advance
 
#8 ·
I have the same problem on my mazda 136cv diesel 2003. When the rpm are under 1200, the car sometimes shut off. I try to start, but it shut off again.

when i went to mechanical service, they said it's a EGR valve problem.

i hope this help you.

bye.

(sorry about my english...)
 
#9 ·
Hi,

I have been again to mechanical service, official for Mazda, and when they saw the problem, immediately change the SCV.
After all, Dave was right. Now my car is working no problem...But this thing is way too expansive!!!

Thanks Dave again,
 
#10 ·
Sorry i've not been on here that often, i'm having pc problems (still am) but at least i've managed to get on here today!
Drozer the MAP sensor can throw a generic code when you get a SCV fault, i expect the cam position sensor has also done this, or it could be an old stored code.
Glad your sorted anyway, Mazda are'nt the only dealers which are expensive, it's the labour charge that does'nt help with some garages charging £80 per hour!

Dave
 
#13 ·
Hi Dave,

I've been to mazda service and they told me that the problem was in the Protege Vacuum Switch Valve (96 Mazda Protege Vacuum Switch Valve VSV #K5T49091 KL015905 | eBay).
The problem that I had is that "Check Engine" lights from time to time.
In the mazda shop told me that this is not a big problem, and that this is a common error of this kind of models.

So, can you tell me, the real function of this valve, and how "big" is this problem?

Thanks,
 
#14 ·
Hi Drozer,i've never heard of such a switch! i've googled it and it seems to have something to do with the EGR valve, so i've looked in the workshop manual and there is a valve that controls the EGR (EGR solenoid valve).
Have you cleaned your EGR yet? if not i would try that.
The valve helps control emissions but can cause running problems if it gets blocked up.

Dave
 
#15 ·
I haven't clean the EGR valve yet. Also I have notice that when my car is in neutral speed, and I hit the accelator paddle, there is a little bit black smoke coming out from the EGR valve.
Definitively I'll clean the EGR valve ASAP.

Thanks ones again Dave...
 
#16 ·
I just want to say thanks to the forum for saving me a fortune! I have lived with the occasional stall, warm or cold, for perhaps a year. In the last month stalls became progressively more frequent, such that allowing revs to drop below even 1500 rpm would allow the engine to stall, after which re-starting was getting more difficult.
So ordered new Denso SCV from internet (£125), had it fitted (£10) - problem solved!
 
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