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View The Full Version : Tip for mass air flow sensor broken



abberello
19-11-2012, 15:24
Good morning, I wanted to make public a thing to me ? happened to me personally, so that if some of the inexperienced has the same problem could "fix it" cos?:

I ? success from one day to the other that the machine is not made pi?... I thought it might be the egr valve or the mass air flow sensor but I didn't know what could actually be why? from the time of diagnosis was all working. The mechanic told me to try the machine with a new mass air flow sensor but not having at hand I decided to unplug the mass air flow sensor...(of course the car is turned off with the ignition switched off). with great happiness? I noticed that it was precisely he who is the problem since the machine already? from the minimal schemes has resumed the shooting of a time... so if there happens to notice a decrease in performance of your car, try to disconnect the plug from the mass air flow sensor, if you notice an improvement, surely ? he is the problem!

Gianpy80
19-11-2012, 15:29

abberello
19-11-2012, 15:41
We need to get it moving the test with the tester, with the car is stationary values are differents... I said my personal experience on the big point. For about 20 minutes, the machine will not turn on the lights, after the yellow light comes on, and the engine will turn off automatically after you reconnect the mass air flow sensor, and walked for 5 minutes.

Gianpy80
19-11-2012, 15:47
it seems to me that with the mjet can you? to make, simply to see the proof, as you say, simply by unsnapping it. Unfortunately on the other you can not. However, if the mass air flow sensor ? only dirty the values you bust, and unless you have the workshop manual to compare them ? difficult to understand them. If, instead, the mass air flow sensor ? just went to their values remain blocked.. for example, we see the measurement of the MAF stuck at 3.2 v fixed.. really? the machine stops at the minimum it should oscillate. Same thing for the temperature.. if you read an air temperature of 80? ? obvious that the IAT sensor (which in many cases is located in the mass air flow sensor) ? burned, and then must be replaced.

marcogolfnera
20-11-2012, 20:34
By unplugging the mass air flow sensor the ecu uses a fixed value, and the car seems to be better..and so to the end..but after several accessions of the key goes into the recovery...you have to disconnect the battery and wait a while...

marcogolfnera
20-11-2012, 20:34
at least that I have experienced on the audi tt turbo

franco75
20-11-2012, 23:56
By unplugging the mass air flow sensor the ecu uses a fixed value, and the car seems to be better..and so to the end..but after several accessions of the key goes into the recovery...you have to disconnect the battery and wait a while...

In some damos I have seen that ? this map instead of the values of the mass air flow sensor, Should be used when the mass air flow sensor not from values consistent with the operating conditions

franco75
21-11-2012, 00:05
it seems to me that with the mjet can you? to make, simply to see the proof, as you say, simply by unsnapping it. Unfortunately on the other you can not. However, if the mass air flow sensor ? only dirty the values you bust, and unless you have the workshop manual to compare them ? difficult to understand them.

Even without the workshop manual ? possible to calculate approximately the air consumption of an engine.
I'll give you a simple example for a Diesel engine that goes to 1000 rpm (without turbocharger) of 2 litres:
since it is a 4 stroke, each round takes the met? of the displacement, and then a litre, 1000 rpm aspires to 1000 liters per minute, for 60
is 60000 litres per hour.
We consider a volumetric efficiency of those rounds of 85%.
the drawn in air at room temperature weighs 1kg per 1000 litres
60000/1000=60
60*85/100=51 kg/h, about 14g/s

I hope I was clear

blackwolf76
21-11-2012, 00:15
in some of the diagnosis, type the bosch that I use for almost all of the cars in the test value from the entry of air mass and measured mass air objective. Just put it in display both values with the car in motion and accelerate, if you deviate to much then it means that there is some problem with the mass air flow sensor, or with the suction unit, type a sleeve broken.

On some drive by unsnapping it work well, such as the 1.3 mj 70cv, while on the other, if you pull the plug the car is not a part of the whole, the type of the grande punto 90HP and the old gasoline car, which began to use this device, such as a turbo ie and old Eighth-note that in case you take a suction hose is planted and there was going to let her leave.

abberello
21-11-2012, 09:56
You say?, diagnosis in hand, new mass air flow sensor, the car stopped and the accellero up to 3500 rpm target value reached 1000 real value 385. You can't? do a test with the car is stationary but with the car in motion, why? from a standstill does not enter the air in the engine while in gear ? different. On the grande punto 75 hp once the light comes on the engine, simply reconnect the socket and after a few minutes it turns off. Remains the error in memory that you can only delete with the diagnosis

blackwolf76
21-11-2012, 15:00
You say?, diagnosis in hand, new mass air flow sensor, the car stopped and the accellero up to 3500 rpm target value reached 1000 real value 385. You can't? do a test with the car is stationary but with the car in motion, why? from a standstill does not enter the air in the engine while in gear ? different. On the grande punto 75 hp once the light comes on the engine, simply reconnect the socket and after a few minutes it turns off. Remains the error in memory that you can only delete with the diagnosis


The mass of the air lens ? that cetralina requires at that time, and the actual ? that the motor reaches, then the values must coincided both moving and stationary...

abberello
21-11-2012, 15:48
tests are carried out on the two machines... both with the same result... a mass air flow sensor had just been discarded and mounted.

sa80libero
21-11-2012, 18:11
on edc16 have you tried this solution? the maps are similar?