Hello guys...

CAR
*07' Mazda Cx7 turbo
Odom- 65km


PROBLEM(s)

I was getting code P2402

Basically Sometimes a feel the truck a litlle heavy on low speeds, sometimes when I realease the throttle you can feel it will keep going smooth and sometimes youll feel like it was stopping with the motor like when you change gear, I also had that , After fuleing the car, it will start turn over and then stall out. I will turn the key again however and push on
the accelorator feed some gas and things will be fine as long as I keep moving. This problem only occurs after fueling and the few moments there after. While at a stop and running, it tends to rumble a little, but not every time, but this was fixed changing the fuel filter.

Now after changging the fuel filter and cleaning the throttle body Im only getting some tugging at randowm and at times the feeling like braking when you realease the throttle and Im getting two different codes

-P2187
-P2402

I must say that if you clear the CEl codes , p2402 wll take a coupledays to reappear.

QUESTION


your help will be very much appreciate.

 

It sounds like you have an evap system problem. The system is to keep gas fumes from polluting the air. As you drive fuel is removed from the tank, a pressure sensor on top of the fuel tank tells the pcm that there is a negative pressure in the tank and the pcm opens the vent valve to add air to keep the tank from imploding/vapor locking. When the fuel tank has a positive pressure the pcm opens the purge valve and dumps the excess pressure into the intake to be burned. It goes through a charcoal canister first to break it down into vapor instead of raw fuel. When fueling, the pressure in the tank goes up and both the vent and purge valve open. Opening the vent valve does allow fumes to escape into the air but is of little consequence since the act of filling the tank pollutes anyway. It sounds like your vent valve is not opening and the purge valve circuit is getting overloaded with raw fuel,so much raw fuel that the charcoal canister can't break it down fast enough. Hence the running rough after fueling until it burns the excess fuel in the purge circuit. One of the codes is an evap leak. A smoker is generally used to detect low pressure system leaks. The evap system max pressure is 1 psi.

 

hey hixx thank your for your reply... it makes sense .... I just refueled minutes ago and it did the same....

Would you be so kind and explain me how could i fix it?

if I wash the canister with gasoline , would that do any help?

thanks

 

It generally requires a scan tool to diagnose properly. Although the vent valve takes the most abuse as it opens into the air under the car to take in fresh air. This means a dirt dobber nest /spiders/bugs can crawl inside it as well as road dirt can enter it and damage the solenoid causing it to stick. It could be the purge valve or a vacuum leak in the purge valve circuit. You could look at the piping/valves from the filler neck to charcoal canister under the car and maybe get lucky. A scan tool and smoker is really the best way to diagnose it though.

 

Hey Hixx... first, thank you for your time and effort.... I hope you got more for me lol...


Is the 2187 code consisting with the evap system failure?

Now im having a light pull, tug(push, it feels like a small push like if I pressed the gas pedal for a sec and the goes back to normal) when braking or slowing down, is this part of the problem? or it might be a different problem related to the throttle boddy? ( I say this because they cleaned)

When you say vent valve is not opening, you mean the one next to the canister? you mean this one? Dorman 911 702 Vapor Canister Valve | eBay




So if change the all canister or in this case the vent valve .. it should be fine??


is there a specialized shop that could diagnose or fix this problem? what could be the name of that type of shop?

the reason Im asking all these questions is because , I dont have many resources at my disposal..... I live in mexico and in my city there are not emitions shops, it is a small city we dont even have a mazda dealership, I had to travel 200km and spent the all day just to they tell me that the 2402 code does not affect the performance of the motor so I had to be maintennce, thats why they changed the fuel filter and the cleaned the throttle body.

many thanks for your patience.

 

Hmm, this is a bit of a tough one being 1000 miles away from the car. A shop with a really good scanner should be able to activate the various solenoids to check them. Possible causes of code p2187 are pretty long and point to system lean ( too much air or too little fuel. The target air/fuel ratio is 14.6 parts air to 1 part fuel.
Possible causes are: Misfire/upstream o2 sensor lazy/o2 sensor pre-heater/MAF/fuel pressure regulator/fuel pressure sensor/relief valve (built into the filler neck)/restricted fuel filter/fuel pump/purge valve/air leak between air cleaner and throttlebody ( Includes turbo piping/cooler)
Cam variable timing (this works using oil pressure and is sensitive to oil degredation) PCM malfunction.

Code p2402: Evap system leak detection pump malfunction/short to power supply to evap system leak detection pump from PCM/PCM malfunction.

As you can see it can get really involved. Personally i would remove the throttlebody,give it a good cleaning and new gasket. Then i would make sure every bit of the turbo/intake piping is secure and leak free. Then i would inspect the filler neck/piping and canister piping. You really need a scanner to check the solenoid activation. Using a scanner insures that this problem is not in the wiring if you can activate them through the PCM.

I wish i had a simple solution for you but it is complicated system without the right equipment at hand. The part you linked is a purge valve and is under the hood. Easy replacement and it is possible it could fix the issue, I really can't say though. I would go after the P2402 which points to the evap system leak detection pump before i put a purge valve on it. You might try checking it for leaks/spider webs/bug nests/etc. Check your filler neck for possible problems internally.

 

I'm glad Hixx mentioned the possibility of leaking air due to bad seals and welds on the turbo piping, intercooler piping.
I think this is usually missed on turbo systems. I would check these systems yearly for leaks.
Hixx has given you great possibilities.
Normally turbo charged engines run a little richer than naturally aspirated on full throttle, around 12:1 whereas normally aspirated is between 12.5 - 13:1 on full throttle.

 

thanks both of you.... Ill do my own check also Ill take the truck to a good scanner (Hope it is)...

Would you agrree if I tell you that the P2187 code could be cause due using a wrong sparkplug? I wasnt avaible to install the iridium ones since they were out but Im using platinum.

Thanks.

 

The iridium is probably a bit hotter if there is any difference at all so i doubt it. As long as they are not Bosch anyway. I use platinum NGK in nearly every make/model/year car i tune up and have had no problems. 3 bucks apiece vs 10 bucks for iridium makes everybody happy.

 

Always run colder plugs with a turbo engine, and always gap closer than you would a stock normally aspirated plug! Remember, on both NGK and Nippon-Denso plugs, the colder the plug the higher the number. Bosch, Autolite, Motorcraft, and every other type is opposite this.
Running iridium plugs may be hotter, going in wrong direction, depending on the proper crossover for the part number. Will it be a problem? If they have been in for a long time, then probably no, but next time get proper heat rating.