Why is an Audi A3 1.9 TDI difficult to start when warm even though diagnostics show normal engine parameters?
The problem is more likely insufficient cranking speed or too small a warm-start fuel dose than non-closing valves: first check cylinder compression, then battery condition, starter speed, starter cables and grounds, and only then the fuel system and starting maps [#12554555][#12585235][#16828752] If the engine does not reach the RPM expected by the ECU during cranking, the controller gives little or no fuel dose, so a weak starter or poor power supply can cause long warm starts [#12585235][#16828752] Several posters say the start dose can be adjusted with VAG-COM/VCDS (login 12233, adaptation channel 05), but this is a workaround, not a substitute for fixing the underlying cause [#12580120] If the mechanical and electrical checks are OK, have a specialist inspect the start maps and the fuel system rather than immediately assuming valve leakage [#12554714][#12602284]
Hello everyone. For some time, Audi has been very difficult to start with a warm engine. It spins a long time before it fires. It does not smoke, it does not take oil, neither is the engine dry and the turbine. I was at the workshop, under the computer and found that all engine parameters are ok. Injections, pump, advance angle and intake temperature. They suggest that it may be the fault of non-closing valves? Is it worth delving into it? If anyone could say something, thank you in advance. Regards.
Thank you for the hints, gentlemen. I was not in the country for a while, but from Wednesday I am going to work and I will inform you about the results. And what kind of Allegro device can you install? Regards.
Gentlemen, with the fact that there is too little fuel dose, I agree 100%, but you do not have to pick and pick up the controller right away. The main reason for the fact that the fuel dose is too low is the starter, which does not spin the engine up to the proper speed. If the engine does not reach the RPM recorded in the controller map, the dose is negligible or not at all. The starter should go to regeneration + improving the weight in the car and the positive wire to the starter.
Hello. I put Audi in a line to a specialist and we'll see what he comes up with, he says he knows what's going on, and I can see that I can't do it myself without the appropriate equipment. I will let you know what and how it was. He mentioned something about the starter, we'll see how it will be. Greetings to everyone and thank you for the hints.
Hello. Audi healed, some 180 zlotys were installed. And the problem is solved. But I'm not entirely satisfied. The engine is somehow artificially overclocked, I do not perceive it this way, because it turns like crazy, burns faster than I have time to withdraw the key, but the revolutions are a bit higher than usual, like 1000 rpm. smoothly, after warming up, they slightly fall off and slightly fluff the smoke when firing. But the worst thing is the ABS sensor caught fire and I don't know what to do next. The mechanics say that they did not bother with ABS, I know, but it did not shine before and not long ago I replaced 2 rear sensors ... Thank you gentlemen for sharing your views on this. We will continue to fight the rest of the problems. Regards....
I have a problem in my Audi A3 8P 1.9TDI BKC with warming up. In the morning, it fires with a cold arrow and a starter on a warm 4-5 spins. As described in the golf forum user's topic. http://forum.vwgolf.pl/viewtopic.php?f=35&t=266408
"As a colleague wrote above, the problem is the restrictive map of the starting dose as a function of liquid temperature and speed.
But a good battery and resuscitation of the pacemaker helps for ... a year ... maybe half (from experience)
Speeding in doses results in a much longer time and does not require replacement of a functional battery with a slightly more efficient one "
"I am not surprised, because in VW Kulikowski in my Mk5 they fought with this problem and unfortunately they did not cope, only changing the start maps in the ECU at the tuner solved the problem definitively, with cases that I encountered personally in MK5 and even MK4 the problem always disappeared after the change start maps "
I got an answer from an honest well-known tuner:
"At 1,000,000,000,000%, this is not a restrictive starting dose map. It is set so that the engine does not start, detonating, destroying the crank system, especially the bearings without an oil film, and the real cause is too low starting speed. Reanimation is not the battery and the starter, but above all. all starter cables and mass. Did any of these smarts change this map in a new vehicle because he does not want to start? Or after a year there was a problem? Rhetorical question. Of course not. But to sum up, if you know all this, you want to load the connecting rod bushings without oil I invite you to visit us with a high dose "
What do you think about it? Better to drive to a company that specializes in the regeneration of starters?
And replacing the wires does not add anything to the topic. The problem was practiced by thousands of workshops and yet no one has found a permanent solution to it in the original. And when it comes to making the dose, 9 out of 10 operators do this dose to the maximum because they cannot do it manually, of course, that something will suffer the crank system, etc. topics. The ground should not be done to the maximum, but as it should be and nothing really happens then .
Not for how long, but forever, if you are made of steel, I invite you, we'll wait while you wait. You'll see how it's done gently and understand the idea of not pumping fuel to the maximum.
hello, a very common problem and everyone does something about it, at the beginning I check the battery, starter speed and power consumption during start-up (fsa and no only has such a function) how is it ok the pressure on the pump. When it comes to maps, you have to tell the truth that it is rather unit injectors that do not have doses, which qualifies them for repair when it comes to an ordinary pump, a plunger and a distributor to be replaced, but we know the reality of repairing the pump, the cost is considerable, and the dose change is small. by 50 rpm
A very common problem and I struggle with it myself. I've read all the internet and a lot of smart people are spreading their hands in the process. However, there is a way, some kind of cheating, and many have probably heard of it. It is possible that the dishonest repair shops "fix" the problem in this way.
Well, you can change the coding of the engine controller to work with an automatic gearbox. If we enter 01-engine in the VAG-COM program, the engine controller number will be displayed, followed by the inscription "soft coding" and the code in the form "00002". This means that our engine is set to work with a manual gearbox. It is enough to click on "07-recode" and enter: "00001" (of course without adultery) and confirm the change. This will result in the car jumping like a frog at low speed and low gears with a slight addition of gas, and an error that cannot be canceled for anything. It is easy to guess that this error informs about the lack of an automatic gearbox The last of the side effects of this forced change will be that there are no problems with starting the engine while it is warm.
Nothing will shine on the dashboard and the car will start like stupid. I hope that my post will not be an instruction for cheaters, but it will help to check the reliability of mechanics. This is not fixing the problem, but masking it artificially.
b1aster, you probably haven't seen a hard tdi on a warm engine, the way you describe the coding change does little but only in the initial problem states. Sloppy tdi because for several years only these have been left, this trick does not contribute anything to the topic and can be used by people like you and totally uninformed mechanics ferns with a hammer and chisel in hand and just like you write a few side effects that are not hard to miss, i.e. everyone Kowalski would know that something is not as if he picked up the car from the garage after such a number. In short, it is not done.
My friend changed slightly fuel doses with VCDS and it burns from the arrow on the warm one. Experts for this service in Warsaw count from 150-450 PLN !!!!
✨ The discussion revolves around the difficulty of starting an Audi A3 1.9 TDi with a warm engine, with users suggesting potential causes and solutions. Commonly mentioned issues include low fuel injection doses, starter performance, and the condition of unit injectors. Several users recommend increasing the starting fuel dose through VAG-COM adjustments, while others emphasize checking the starter and battery. Some participants mention using devices to simulate cold engine conditions to improve starting performance. The conversation highlights the importance of diagnosing the root cause rather than relying on temporary fixes, with suggestions to consult specialists for proper repairs.
Can ECU coding to ‘automatic gearbox’ solve the problem?
It can, but side effects include jerky low-gear drive and an unerasable gearbox error—an edge-case hack, not recommended [Elektroda, b1aster, #16877589; jokerro, #16878172].
When should I rebuild the fuel pump or unit injectors?
If compression, cables and starter test OK yet warm starts still need >3 s and adaptation is maxed, plan pump/injector bench test and overhaul (~1 000 PLN) [Elektroda, andrend, post #12581694]
How much do workshops charge for software-only dose correction?
The last of the side effects of this forced change will be that there are no problems with starting the engine while it is warm.