PicoScope 7 Automotive
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Audi a4 2.6 v6 rough running, misfire
Audi a4 2.6 v6 rough running, misfire
Hello,
I have the following problem with this Audi a4 2.6 v6.
The car is running bad and misfiring on bank 1, measuring lambda at this bank showing it runs lean until it goes into limp mode and then it starts running a little bit beter, bank 2 runs good lambda is switching good.
They owner pulled the cylinder heads because the valves where leaking, also swopped the injectors from bank 1 to 2 but the problem stays at bank 1.
My thought is mechanical. I made a fls intake cranking and also wps cyl 1 and cyl 4. cyl 1 is bank1 and cyl 4 is bank 2. I find the pressure rissing before the intake valve opens at wps 1 a little bit strange.
Also a capture with the mixmaster during running.
Any Thoughts?
I have the following problem with this Audi a4 2.6 v6.
The car is running bad and misfiring on bank 1, measuring lambda at this bank showing it runs lean until it goes into limp mode and then it starts running a little bit beter, bank 2 runs good lambda is switching good.
They owner pulled the cylinder heads because the valves where leaking, also swopped the injectors from bank 1 to 2 but the problem stays at bank 1.
My thought is mechanical. I made a fls intake cranking and also wps cyl 1 and cyl 4. cyl 1 is bank1 and cyl 4 is bank 2. I find the pressure rissing before the intake valve opens at wps 1 a little bit strange.
Also a capture with the mixmaster during running.
Any Thoughts?
- Attachments
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- Audi_A4_1995_Petrol mixmaster running.psdata
- (28.31 MiB) Downloaded 439 times
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- Audi_A4_1995_Petrol wps cyl 4 running.psdata
- (7.86 MiB) Downloaded 492 times
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- Audi_A4_1995_Petrol wps cyl 1 running.psdata
- (5.16 MiB) Downloaded 454 times
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- Audi_A4_1995_Petrol fls intake cranking.psdata
- (14.26 MiB) Downloaded 455 times
Re: Audi a4 2.6 v6 rough running, misfire
Hi, Have you checked cambelt? Timing looks not right to me. Your idle is in the 600rpm and the plug fires
at 2-4deg ATDC.
Kind regards
at 2-4deg ATDC.
Kind regards
Re: Audi a4 2.6 v6 rough running, misfire
No not yet, I only did the scoping hoping someone could shed a light on it.
But I am going to check the timing with tools.
But I am going to check the timing with tools.
Re: Audi a4 2.6 v6 rough running, misfire
Timing checked with tools, timing is oké.
Re: Audi a4 2.6 v6 rough running, misfire
Hi, how about compression with wps,crank sensor and secondary. Same for cyl 6 and send psdata.
Kind regards
Kind regards
Re: Audi a4 2.6 v6 rough running, misfire
Solved the problem, because the problem started after the head was off, I focused to much on the timing issue. After checking the timing mechanical and this was good I looked good at it again, when the lambda was active, bank 1 showed in the live data 0,7 lambda so this is rich but measuring at the lambda was lean, voltage was low until car got into limp. This is strange so decided to disconnect the lambda to see what happened and the data again showed 0,7, after checking the wiring it must be the ecu. Found a other ecu and the car is running good again.