Hi Scotty,
Hope you are doing well. Recently I was looking at live data of my car (Opel Astra 1.4 petrol 120 miles).
I am concerned about timing advance data. When car starts and its cold its timing is about 3-6 degrees but when car heats up and drops on idle speeed 840 +- 20 timing advance drops below 0 (-2, -3) than back to 5, 6. Also when I rev the car it goes higher (normally) and then when it drops it goes down to -10 or even -14.
No misfires or any error codes. Im using small bluetooth diagnostics and I have only this timing advance data.
What could be the issue , and what should I check for ? Im confused because I saw on internet there says it could be couple of things.
I changed sparkplugs, ignition coils and timing chain seems fine when I inspected it.
Thanks Scotty !
That car is not sold here in the United States so most of us have no experience with it or service information for it. How far off is what you're seeing from the factory specification for the timing curve?
@chucktobias This is a Z14XEP Ecotec engine which is GM manufacturer. Similar engines that chevrolet uses. For example chevrolet lacetti 1.4 is similar with mine.
The Laceti is not sold here either, at least not under that name. Although the basic engine may be the same as GM vehicles sold here there will be differences in detail and electronics for different markets and to meet differing regulatory requirements. You need to know what the factory specs are for timing in order to determine how bad the problem is, or if there even is a problem.
@chucktobias It says that is ECM controlled and I couldnt find anything on the internet although I searched every forum.
You will not likely find the necessary information in a forum, you need to consult a factory shop manual for the specifications. Here in the U.S. it's possible to get an inexpensive short-term subscription to Alldata to obtain in-depth service information if it cannot be found for free online. I don't know what's available in your market.