How most to check a potentiometer of a butterfly valve?
the Situation in which I had to face malfunction of Audi 80 B4 on the way was a push to independent studying of the device of this car.
Moreover, the last trip on station HUNDRED for diagnostics poured out in 30 dollars, however did not yield result. The master declared that indications of the computer at the diagnostic stand meet standard, fuel pressure as he on new and why the car is started, but does not go - he cannot understand. The set of recommendations about an occasion of trial replacements of some knots arrived. Such method of search of malfunctions could pour out in the sum of 300 dollars. Therefore essential changes after visit of service station did not happen. On a tow arrived, with its help and left.
The only plus was the fact that there was no wish to leave the sum of three hundred dollars, and it was motivated incentive to studying of some knots of the car.
My article “ How to check the regulator of provision of a butterfly valve? “ has directly something in common with this article which is continuation of studying of the elementary diagnostics of some knots of this car in house conditions.
The potentiometer, as well as the regulator of provision of a butterfly valve, is established on the block of preparation of gas mixture.
Purpose of a potentiometer of a butterfly valve is that the angle of opening of a butterfly valve then information is transferred to the control unit for calculation of necessary amount of fuel at the moment to time at the present provision of the gate decides on its help. Depending on a corner of provision of a butterfly valve, on a potentiometer resistance which provides the corresponding tension for transfer to the control unit changes. That is the potentiometer of a butterfly valve generally represents variable resistance. Therefore, check of its work is reduced to measurement of resistance on potentiometer plugs.
Measurement of resistance is performed by the device the ohmmeter or other device capable to perform measurement of resistance within 300 - 7000 Ohms.
It is necessary for measurement of resistance:
1. On the device to choose the range of the performed measurements to 7000 Ohms;
2. to Separate the shtekerny socket of a potentiometer of a butterfly valve;
3. to Connect an ohmmeter to two of four shtekerny contacts of a potentiometer;
1 - 5 contacts - for the engine with a mechanical transmission;
1 - 7 contacts - for the engine with an automatic transmission;
the Size of resistance has to make 520 - 1300 Ohms.
1 - 2 contacts - for the engine with a mechanical or automatic transmission;
Measurement are carried out together with the workmate. The workmate has to change the provision of a butterfly valve from “ it is closed “ to “ it is open approximately on 1/4 “. At the same time resistance has to increase and then becomes constant within 600 - 3500 Ohms.
1 - 4 contacts - for the engine with a mechanical transmission;
1 - 6 contacts - for the engine with an automatic transmission;
As well as in the subparagraph “ B “ measurement are carried out together with the workmate. The workmate has to change the provision of a butterfly valve from “ it is closed “ to “ it is open approximately on 1/4 “. At the same time resistance has to increase and then becomes constant within 600 - 6600 Ohms.
4. If when carrying out measurements the specified values of sizes of resistance are not reached, then the potentiometer of a butterfly valve is faulty.
Unfortunately, it should be noted that the potentiometer is not subject to dismantling. Its control is made at manufacturer and if replacement is required, then the lower part of the block of preparation of gas mixture is replaced.
Such simple diagnostics of a potentiometer of a butterfly valve of the Audi 80 B4 car is available to any driver of the car who knows bases of a school course of physics and made laboratory works on measurement of resistance of a chain.