I have been with problems for a week when my megane 1.9 TDI started, after many laps I discovered that when tightening the barley pear before operating the starter engine, I managed to scourge the first.
The
injection system of this car carries a control unit (calculator), Lucas Ecu DCN R04080001C, which takes data from:
crankshaft
regime
collector injector
raised collector No.
1 Advance, it is a solenoid valve integrated in the injection pump that according to the voltage with which it feeds produces a reduction in the pressure inside the injection pump to obtain a delay in the injection if it is without current, or a preview of the injection if it is fed (more progress as much more tension is applied, at least that says the workshop manual). The explanation that squeezing the barley pear helps the ignition is that by increasing the pressure inside the pump we create an advance in the injection.
I also verified that when it gave contact, the solenoid valve (progress concealer), was then operated and turned off (looked like a submachine gun) for 8 seconds, exactly the time that the operating pilot of the preheating spark plugs was on, later it was left out. I thought it was a breakdown and began to look at the values of all the captors without finding a solution.
I put a voltmeter to the cables of the solenoid valve to measure the tension that came and see what happened during the start, in the end I discovered that the failures of starting and stopping are not such failures, it is simply because it lacks the signal of the raised collector of the number 1 injector (it is logical, the engine does not move).
When the starter engine is operated, the injection begins, but if not, there is no data from that sensor, after the first eight seconds, the feed is completely cut to the advance valve. It is feed again when the control unit detects movement in the injector (by then we have already lost a couple of crankshaft or more).
Therefore, also as it favors the start, press the barley pear before the starter engine, which we have managed to create a certain pressure in the circuit and advance the advance, also favors the starting to give contact and once the heating light goes out, turn the key to the off position and immediately re -drive the key and start.
The explanation is simple, we return to the cycle in which the progress concealer is fed alternatively (until the heater light is turned off), we take advantage of the progress that the calculator is creating without the need to take data from the lift collector of the number 1 injector Favoring the start and the heaters have not cooled because the operation of turning the key back and forward has been very fast, also once the key reaches the starting position they act again.
By the way, for those who do not know, the heaters are not disconnected once the preheating light of the painting is turned off, then they enter a post -heating phase and continue to function for a time still with the engine running (up to 30 seconds if it is much cold or the water temperature probe is defective).
I mean: things that can help start the 1.9 TDI engine of the cold megane:
- Raise the hood and press the barley pear two or three times until we notice that it gets hard.
- Go to the cabin, put contact and when the preheating witness is turned off, turn the key in the sense of turning off to the end and immediately act and start it again.
However, I still believe that something is not going well in the calculator, any sensor or something is wrong, but well, in case of starting problems and until it is correctly solved that you know that it can help you.
Greetings from a new member.
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