Timing showing advanced when retarding..

[bambacoot]

Still having some issues with the timing not showing accurately. I've updated to the correct firmware which actually got the engine running much cleaner but hasn't solved that timing issue yet. Im the Vanagon owner from the previous thread.

[Hahns5.2]

You mean not accurately compared to a timing light? Because your log seems to match the timing commanded in the tune.

[bambacoot]

Exactly... The timing light shows the opposite.

[bambacoot]

We are also having trouble keeping a consistent idle.. Sometimes it will hold an idle at 1k and other times, as the engine warms, it idles at 4k.. This whole system is very new to myself and my mechanic so we appreciate all the help!

[whittlebeast]

I am suspect that what you are looking at is just messing with your head. Lets assume you motor spins clockwise. Say you are idling at 15 degrees advance and your timing mark is straight up above the top of the front pulley. As you rev the motor the 15 degree mark mark will appear to move to the left as you stare at it with a simple timing light.

https://www.youtube.com/watch?v=RG3s4MzTheQ

Andy

[billr]

Do you have a "simple" light? Dial-back ones can be even more confusing...

[kingtal0n]

1. the idle speed has to do primarily with air intake. If you have an inconsistent idle, you have a leak, or a device is acting like a leak. I recommend a pressure test (boost leak test) to find all leaks; then configure or replace whatever idle speed devices are causing the 'leak' (the air is bypassing the throttle body to cause the idle up condition). Put it this way: if you blocked off the idle control motor(s) (assume this isn't a drive by wire) then you should be able to "kill" the engine by putting your hand over the throttle body and stopping all airflow. If it continues to idle this way there is a leak somewhere.

2. With the engine at idle, begin to advance timing. If the idle speed seems to increase slightly as you advance the timing then it is correctly advancing the timing. Adding timing generally increases idle speed. Its just a handy quick way to verify if you are really getting a retard condition; in other words if you start advancing the timing at idle and the timing is REALLY retarding, the engine will gradually die and shut off eventually as you go farther and farther.