Search found 15 matches

by nelnun
Wed Aug 22, 2018 3:03 pm
Forum: Diagnostic discussion
Topic: Audi A4 2.0 TDI Rough idle
Replies: 46
Views: 97237

Re: Audi A4 2.0 TDI Rough idle

Hi all, I've been doing a lot of logs to try to understand what is going on! After rollback to v.6190, the problem came back! I've made some tests to the PRV and IMV with a PWM emulator, as following: - PWM emulator on the IMV: PRV is able to maintain rail pressure stable from 0% dutycicle until IMV...
by nelnun
Wed Jul 25, 2018 7:55 am
Forum: Diagnostic discussion
Topic: Audi A4 2.0 TDI Rough idle
Replies: 46
Views: 97237

Re: Audi A4 2.0 TDI Rough idle

Hi all! Just a quick update! I've bought ODIS to upgrade/downgrade the ECU software. I changed it from version 6190 to 5597 and nothing has changed! Then, I changed it from 5597 to 9980 (fix file) and the rough idle problem has just disappeared! Maybe, the issue is still there, but as the injection ...
by nelnun
Sat Mar 03, 2018 2:53 pm
Forum: Diagnostic discussion
Topic: Audi A4 2.0 TDI Rough idle
Replies: 46
Views: 97237

Re: Audi A4 2.0 TDI Rough idle

At the moment, I can discard the injectors, once they were already replaced (refurbish by bosch)! Reading the injection deviation oh the 4 injectors, when it is failing with rough idle, there are always one cylinder that increases deviation above 1mg/str, but it a kind of random thing, as sometimes ...
by nelnun
Tue Feb 27, 2018 10:22 am
Forum: Diagnostic discussion
Topic: Audi A4 2.0 TDI Rough idle
Replies: 46
Views: 97237

Re: Audi A4 2.0 TDI Rough idle

On the 1st and 2nd red box, coolant temp was set to ~33ºC and it was idling perfecly, as you can see on the RPM flat line. Then, the 3rd red box, I've increased coolant temp to 120ºC (fans stared spinning, message in the MFD and red temp light on) and it was idling perfect as well, but the reason he...
by nelnun
Mon Feb 26, 2018 9:29 am
Forum: Diagnostic discussion
Topic: Audi A4 2.0 TDI Rough idle
Replies: 46
Views: 97237

Re: Audi A4 2.0 TDI Rough idle

Can we see a Crank Sensor waveform, with at least 4 or 5 revolutions across one screen, when it is running bad ? Hi shooter, thanks for your reply! I don't have it, it is really hard to access the sensor! But why would that be a problem if when I simulate a coolant temp below 40ºC or above 50ºC it ...
by nelnun
Tue Feb 20, 2018 11:43 pm
Forum: Diagnostic discussion
Topic: Audi A4 2.0 TDI Rough idle
Replies: 46
Views: 97237

Re: Audi A4 2.0 TDI Rough idle

Meanwhile, I've made a few more tests! I've connected a potentiometer to the coolant sensor plug to emulate an engine temperature of my choice! I've emulated 41ºC and 45ºC in a cold and warm engine! With the engine cold and 40ºC of emulated temp, after around 5s of start and there is the rough idle ...
by nelnun
Tue Feb 13, 2018 3:00 pm
Forum: Diagnostic discussion
Topic: Audi A4 2.0 TDI Rough idle
Replies: 46
Views: 97237

Re: Audi A4 2.0 TDI Rough idle

This is how it idles! Unfortunately, this time, I was unable to have a very rough idle to show you the engine failing and shaking, it is difficult to replicate when the temp outside is cold (13ºC o this case), but it is there and it is "visible" when I start moving the car, as it kangaroos till arou...
by nelnun
Mon Feb 12, 2018 9:15 pm
Forum: Diagnostic discussion
Topic: Audi A4 2.0 TDI Rough idle
Replies: 46
Views: 97237

Re: Audi A4 2.0 TDI Rough idle

About the rail pressures. This is a normal cold start. Spec value is always stable, it is always the same, only actual pressure fluctuates a bit, but I think that's normal: Cold Start Rail Pressure_4.jpg And this is what I think that is not normal, pressure spec fluctuating a lot. Why is the ECU con...
by nelnun
Sun Feb 11, 2018 10:45 pm
Forum: Diagnostic discussion
Topic: Audi A4 2.0 TDI Rough idle
Replies: 46
Views: 97237

Re: Audi A4 2.0 TDI Rough idle

Hi Nelnun The injectors you replaced are they new or used and have they been recoded with the correct IMA number from the injectors !!!. Regards Kim Hi Kim, They are all 4 refurbished by bosch. IMAs were recoded, but it doesn't matter as when the engine has a rough idle, it is behaving the same way...
by nelnun
Sat Feb 10, 2018 9:57 pm
Forum: Diagnostic discussion
Topic: Audi A4 2.0 TDI Rough idle
Replies: 46
Views: 97237

Re: Audi A4 2.0 TDI Rough idle

What do you think about the difference between Rail pressure Specification and Rail Pressure Actual?
Could this be related to a faulty DRV?
Rail press 2
Rail press 2
Injectors already replaced with no joy... :roll: