Frank@Work

I am getting strange results adjusting my AFR. Sometimes when I try to lean out a zone it actually gets richer. Or sometimes when I do not alter anything in the upper rpm range it does change!

I was wondering if this may be caused by then chips using a different ignition timing when no knock is detected.

I can put it different: does the ingnition timing influence the AFR?

Thanks!

NZ951

Hey Frank, in my experience more advanced ignition leans the AFR out.

special tool

What means are you using to change afr?

Frank@Work

I am using a piggyback (SplitSec PCS1-003) to adjust the AFR.

special tool

Do you have an AFM or MAF?

Frank@Work

I am using a MAF (LR) with a temperature sensor, Guru Chips and a SplitSecond piggyback.

special tool

Frank -I don't know if you want to hear what I have to tell you.
You might be able to band-aid your setup to cover one boost level - but it will not be optimum. Your DME does not know what is going on. I think you are seeing this now - you are not doing anything wrong - if that is any consolation.

A set of real Motronic MAF chips (not massaged AFM chips) will cure the problem.

Frank@Work

After run1 I tried to make the zone at the white line leaner and the zone after the rich dip a little richer. The result of my attempt is run2.
I did not to anything to the upper rpm range, but it is a little richer. The zone I tried to lean out is also richer and the zone I tried to make richer is leaner. (I do know how the add and substract! )

Run1:

Run2:

Frank@Work

@Special Tool: as far as I know it are MAF chips! I can't imagine that a set of (for example) Vitesse chips would be on spot right away. Too much variables to cope with.

special tool

Frank - no you are missing my point. Those are not real maf chips - they are massaged afm chips sold as maf chips.

Frank@Work

Ok.
Can you (or someone else) explain what the big difference is between MAF chips and massaged AFM chips. Why am I having such a hard time getting the AFR where I would like it to be?

awilson40

based on your graphs, it shows the 'massaged' MAF voltage and going up from 3.27 v to
3.41 v...that would drive it richer.

jimbo1111

Are you logging the voltage from the maf or the massaged signal? The way I do it is by logging the maf signal . Than go to that voltage cell in the piggy look at rpm where they meet. If it is possible to log both load on the piggy and load that the dme to make sure the dme see's no more than 4.7 volts. The voltage from the maf will be higher than the piggyback signal output. If you have a maf meter small calibration like mine. It all boils down to the size of your meter 19 24 or 30 lbs and that will dictate where in the volts you will be. Some maf meters can read past 5.5 volt. The dme is only capable of reading 4.7 max. I am maxing out my meter at close to 6 volts. But the dme's volts are 4.7

Frank@Work

I am logging the voltage comming from the MAF. I have never seen more than 4.3 Volts comming from the MAF.

Is there a way to test the temperature sensor in the MAF. It may be faulty, causing incorrect adjustments in the MAF meter.

jimbo1111

Posted by Frank@work: I have never seen more than 4.3 Volts coming from the MAF.
That ok You may not be pushing you car as much as I am, your meter is larger or you have 72 lb injectors. To do it as easy as possible log maf voltage with your zitronics and log load with the r4 software at the same time. If you have very large injectors you can raise the voltage out put on the piggyback by dropping fuel pressure if you have an adjustable one. As you start to make more power the voltage goes up as well because of the added load. There is also a quick way to get you started. If you run the r4 software while you do a run you can get an magic marker and just draw a line across your laptop screen following the highlighted cell than make changes to the cells later.