Normal timing advance at idle

Hi,

Based on the manual, what you listed seems to be within the manufacturer's specifications. When you feel hesitation, is there any notice of a power loss prior? Also, when you scanned the computer, did you use a scanner capable of reading all codes (can-bus)?

CAN stands for controller area network. If there is a code stored in any of the modules, this will identify the code. If you are using a basic scan tool, most only read engine codes.

Here is a link explaining how it's done:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Also, the idea you don't feel it until the 2/3 shift, there could be a low fuel pressure issue. Let me know if you have checked fuel pressure.

I will watch for your reply.

Take care,

Joe

Hi Joe!

I'm using iOS app inCarDoc Pro with an ELM327 v1.5 ODB II Wi-Fi interface. The connection protocol says 6-ISO-15765-4 CAN.

The jerking is 1-2 seconds after I feel the transmission made the change from 2nd to 3rd. Between 1600 - 1900 RPM.

On idle, Fuel System bank 1 shows -0.75%, bank 2 shows -0.43%.

On a short test (where the problem also appeared), I got:
Short term fuel % trim Bank 1: Min. -16.41 Max. 7.03 Avg: 4.41
Short term fuel % trim Bank 2: Min. -14.06 Max. 5.47 Avg: -4.19
RPM: Min. 524 Max. 1,806 Avg. 1,151.04
Fuel Level Input: Min. 40 Max. 41.18 Avg: 40.97
Engine Load: Min: 16.08 Max. 49.02 Avg: 30.58

I cannot find a Fuel Pressure parameter on the scanner.

Besides changing the MAF for a new one, I also replaced the spark plugs with new ones (bought from the MB dealer).

Thank you again!
Guillermo

Hi,

During the "Short Test", was the engine at operating temps? The fuel trims are indicating a rich mixture. The two different readings above tell me when they were done. For example, one was at operating temperature and the other wasn't.

Also, can you drive the vehicle with the scanner connected to see if there is anything that jumps out when it happens? For example, do the oxygen sensors drop to 0v, or does the MAF signal jump?

Since there are 0 codes and it sounds like an electrical connection issue, I have a feeling we will need to identify it when it happens. Maybe you could have someone drive while you watch the scanner.

Let me know.

Joe

Hi Joe. The cooling temperature at the moment of those readings was around 90C (194F).

They were taken in a 30 seconds period drive, from still start to complete stop.

I will find someone who can drive the car while I watch the scanner as you suggested.

Keep you posted.

Thank You!

Hi,

Thanks for the update. When you are watching the scanner, stay focused on it because the issue could be difficult to catch.

Take care of yourself,

Joe

Hi Joe,

I'm sending you the scans, indicating the moment of the hesitation/jerking.

Temp: 81C
Green line: RPM
Orange line: Fuel level Input (%)
Blue line: Short term fuel % trim - Bank 1
Yellow line: Short term fuel % trim - Bank 2
Red line: Engine load (%)

The jerking is more notorious when the AC is on.

I drove the car around the neighborhood for around 7-10 minutes.

Still no DTCs. on the scanner.

I hope this can help a little...

Thank you again!
Guillermo

Hi,

Is the circled section where you noticed the issue? I ask because I'm not seeing anything standing out.

Let me know. Also, sorry for the delay in responding.

Joe