[Sailor24]

I would add a fuel filter to the maintenance list to. Low MAF test is low air or low fuel. Mileage is low but years are long.

 

[Sailor24]

More often than not in "alarm" posts like this, a new member is attempting a MAFS test, gets to Test 4, but forgets to choose the right units for read out.

Excellent Point + 1 gillion

 

[Sailor24]

It is not only about air or fuel.....

The so-called "MAF-test" is a calculated combination of many other factors as well.Like Vanos(CPS,Solenoids,...),even cam timing plays a role....

Also lower octane fuel plays a role due to re tarded ignition timing...

I was wondering because... Thanks! of coarse intake valves control how much air too. CPS say how long to do A or B. I will also add exhaust valves and NOx emissions.
How much of an allowance could we give those things? Would 20% be too much?

 

[Sailor24]

I see your point but most of those things would be gradual. So is a fuel filter and an air filter.ouich Which is what cab just posted to this thread. He has done lots But only pulls 120s. I would suspect a very low reading to be one of the majors however. You have to start with the basics and rule things out. Right or wrong fuel or air both would have to be ruled out before you move forward with more complicated diagnosis. Hopefully as you go through the basics with the poster, he feeds you some info that might help. So I agree every part of the engine plays a role in the MAF test. You have to start somewhere though and if you make it to complicated no one wants to DIY.

 

[Sailor24]

How old are your CPS? Have you replaced your Vanos o rings?

 

[Sailor24]

My point is just that MAFs can help,but the rest basic maintenance(means CPS,fuel filter,solenoid O-rings) should also be done...

But this is the reason I changed EVERY sensor and replaced/rebuilt EVERY actuator on my engine(even use 2 new solenoid boards in my mental illness...:grinyes

Well then we can be insane together because I will have done exactly the same. I made my list and have already burned a hole through my right pocket soon the left will be on fire. Well except for the boards you definitely got me on that one.

I could not agree more the general maintenance is absolutely critical for these cars. Especially the health of the vanos.

 

[Sailor24]

Original CPS as well as vanos o-rings. Vanos doesn't make any noise if that's an indication of anything..

You are in for some fun DIYing. CPS are critical there is no other reference for the computer except the other CPS. The original have proven to be less than perfect. In some cases, like my car, until they are replaced the comp could not figure out what was wrong with the vanos. A trip to a GT1 test is likely half the cost of replacing all four. Lots of posts on the topic some recent good ones. Vanos is very important part of making the M5:M5launch: what it is. If that system is of bad health then getting the rest in good health is probably impossible.

Congrats on your new ride.