Hey hey, so I'm aware that code 12 ( one long two short)and that is related to the airflow meter circuit. I had a look at the connection, it looks alright, no corrossion or anything, the fuse from what I can see looks alright. Can anyone add any addittional things to look for? My dilemma is that I am a uni student living off student payments, just covers the essentials.In the process of acquiring a job. But for now, broke, can't even afford to buy a new MAF. Car is running, but its kicking some dirty smoke out the back if I start it, but its running really rough, cutting in and out. Rpms not idling consistently. ANY advice would be great! Cheers .
If you think it's the airflow meter you can test it by unplugging it then starting the car. It will start in safety mode with a 2500rpm rev limiter but if it runs smoothly then that could be your problem.
Car started from at uni with a 2500rpm rev limiter yesterday, and I was able to make my way back into town. I took it out and looked around it and put it back in and tested it again down the street, still 2500 limiter. Fiddled with it again tonight and built my way up to 2500 revs in park, but can it exceed that in park? Didn't take it for a drive because it was kicking out dark grey smoke and idling poorly
Check all your connectors under the bonnet for corrosion and condition. Especially injectors / coils / p.t.u / and c.a.s. Although not related to a code 12 the may be the reason it is running bad. Code 12 would normally be caused by corrosion or faulty connector on the m.a.f or at worst a dodgy m.a.f. or WATER in the connector or m.a.f and if you have a pod filter and it has been raining ( puddles or just pissing down ) likely cause. As said disconnect it and see if it improves. Cheers Dave
Play around with the wiring connectors while the engine in running. A quick blast with wd40 cleans up the contacts in the connectors if that is all it is.
Unplugged the MAF and turned it on and it ran fine xD, with the 2500 limiter. I'll give the wd40 a go tomorrow! and play around with the connector while its running to see if its just that. If its the MAF itself, is there no other option but to get another one?
Tells the ECU the volume of air flowing into the throttle bodies. If its not plugged in the ecu doesn't know where to put you on its fuel/air map. Hence the 2500 RPM limit.
better to use actual electrical contact cleaner (I uses a CRC product) and best of all no matter what you use dont put any on the hot wire in the AFM. Yes I know there are products that can be used safely but as a general rule I advise against any spray cleaners on it - espscially brake cleaner - as I tried to tell the young apprentice at work but his father knew better and........ well I am sure most of you know how that ended.
So i'd see a higher fuel consumption running the car under 2500RPM? It's just I need it to get to uni which is like 10km away, so would it be bad for it running it with no MAF until its fixed?
keep a good filter in front of it - chances are high you should not need to clean it. in the last year I have personally seen 3 seperate AFM's ruined by people cleaning them with various cleaners. If I had to use something I would go for electrical contact cleaner but the air filter is there for a reason and there should be little contamination on the hotwire.
From the K&N Filter site: Hot Wire Unlike air flow meters, hot wire or hot film mass air flow sensors directly measure air mass, as the convective qualities of air are affected by factors like temperature, humidity and density. Hot wire sensors create an analog signal and hot film sensors a digital frequency signal. Most common hot-wire MAF sensors use a platinum wire or filament heated to a prescribed, maintained temperature above ambient, located centrally in the incoming air stream. These sensors function on the electrical principle that resistance increases with temperature. As intake air moves past the wire or film, the cooling effect causes a measurable drop in resistance, and thus lower voltage is required to maintain the prescribed temperature. The hot-wire MAF control unit is sent a reference voltage of 5V, and returns around .4V to.5V at idle and from 4.5V to 5V at full throttle. Based on a fixed data set, an accurate assumption of air mass is made. Readings can stray from the target values as a result of contamination of the wire and for the sake of accuracy, an additional input from an integrated intake temperature sensor is sometimes used. Many hot wire MAFs incorporate a burn off cycle when the ignition is switched off, heating the element to over 1800-degrees F to clear it of contamination. Hot wire sensors are the most physically delicate and easily contaminated of all the air flow and mass sensors. Mass Air Flow Sensor Contamination: Contamination of hot-wire type sensors does occur. Usual suspects include substances like silicone potting compound, dirt, oil and spider webs. Potting compound, used in the manufacture of the sensors to environmentally seal them can migrate onto the wire. Oil most often enters a MAF in the form of vapor via an engine?s PCV system. In an effort to lower emissions, positive crankcase ventilation systems use a PCV valve to draw fuel and oil vapors from the crankcase, this can allow blow-by gases to make it past the piston rings, and reintroduces them into the intake system upstream of air flow metering devices. When a throttle body or airflow meter needs cleaning, the oily film that is removed is largely a product of this system. Testing: Below are some of the relevant findings: 1. K&N?s laboratory technicians tested an over-oiled K&N air filter at a rate of 1,000 Cubic Feet per Minute (CFM) on our Filtration Test Stand which utilizes an absolute filter. An absolute filter is one specified by ISO 5011 (SAE testing protocol) which is used to capture test dust that passes through a filter during efficiency testing. In this case, an absolute filter was used to capture any filter oil leaving the filter and to allow us to measure any oil migration from the filter. We weighed the absolute filter before and after the test and confirmed that oil does not migrate from a K&N air filter ? even at CFMs far in excess of those seen in production engines. 2. We coated both hot wire and film style sensors with K&N filter oil in both controlled (laboratory) and uncontrolled (real world) environments - none triggered check engine lights. We created extreme conditions, beyond anything an engine would ever experience such as submersing a MAF sensor in filter oil and monitored the sensor readings while spraying it with test dust. Even under these circumstances, the MAF sensor was not damaged. In addition, we were able to take this same MAF sensor, clean it, and found that the readings were identical to the ones taken prior to the extreme testing. 3. A majority of the ?failed? sensors we retrieved from dealerships had not failed at all. They tested to be functioning within normal operating parameters as calibrated against new sensors purchased through dealership parts and service departments. 4. Few, if any, automotive dealership service centers have the testing equipment to authenticate a mass airflow sensor failure. 5. Many of the sensors tested were self-contaminated by the silicone potting compound used in the manufacture of the MAF. Some manufacturers have issued TSB?s (Technical Service Bulletins) advising dealerships of the occurrence of MAF?s contaminating themselves with their own silicone potting compound. 6. Sensors fail and are even the subject of full recalls by vehicle manufacturers.
I had a big ass K & N oiled filter on my Zed when I bought it. The idle was annoying me. I cleaned and re oiled along with cleaning the m.a.f . It came good then a week later the same funny idle. Changed to a dry pod filter and has been fine ever since. I would try a dry type filter and clean the m.a.f . I'm no longer a fan of K & N filters. Cheers Dave
