How to rescale the fuel when upgrading pump?
 

Hi; I've been facing fuel consumption problems ever since I went from the 190lph Walbro to the 255lph one. Could anyone tell me what settings to change?

I've reread the manual and haven't found any answers.

Thanks

probably the best solution is to let the AEM autotune the map again or tune it by datalogs.

it's unlikely that the pump's contribution to the fuel consumption issue is predicable enough to change the map without re-tuning somewhat.

Thanks Matt. FWIW (and that's precisely why I'm selling the AEM and bought the Adaptronic) I couldn't get the tuner to help me and I've never used the AEM autotune. It just proves the fact that it was too complex for me to use without some help.

I assume I would need to run the car in closed loop for that and I never learned how to.

Curious why you decided to go to the 255?

I faced some AFR issues after dynoing the car. I found myself with AFRs at 15 when going into boost and smelling fuel in the cabin. We checked everything. I bought a new O2 sensor for the wideband and a larger fuel pump (the 255). It turned out to be the fuel filter. By the time we found that out, I had already installed the 255.

JasonC SBB is probably the best guy to ask about AEM autotune. Hopefully he'll see this thread or a PM you're about to send him :D

hey rafa, you may find the AEM forum useful if you're not already there:

AEM Performance Electronics Forum - Index

Thanks Matt. I'm already subscribed there.

No need to do auto tune on AEM EMS.
Most everyone with AEM EMS sets it to use the boost comp method. This way one can tune the fuel perfect in no time.

I don't know how to express my gratitude!

I should take the time to explain what I mean: I read your post and went back to the AEM manual (for the umpteenth time!) because I had no clue about it. Since I didn't find anything about the "boost comp method", I decided to google it and found this: AEM EMS Guidebook/Methods of tuning - Wikibooks, collection of open-content textbooks

Many thanks! :bigtu:

My car had become undrivable.

I hadn't read anything so clearly put about the AEM anywhere else (manual or their forum).



You definitely know your shit! :bowdown:

oh right, boost comp.