![]() |
|
|
|
Registered
|
MFI gurus, help me understand
Gurus,
I'm busy fine tuning my MFI set up. Followed all steps of CMA. I have a AFR sensor connected to the left HE. I looks like idle is ok (13.5), part load a little too rich (14-15) and far too rich while cruising (10-11). What are good values? I was wondering, what if one of the cylinders sometimes misses, would that influence the AFR reading? The sensor is connected to the left HE, what about the right cylinders? Thanks, Ed
__________________
72 911E Targa (fun car) BMW 535i Xdrive (work car) Volvo XC90 Ocean Race (family car) VW T2 Riviera Camper van |
||
![]() |
|
Registered
|
__________________
72 911 Although it is done at the moment, it will never be finished. |
||
![]() |
|
Registered
|
Thanks, now I re-read that thread I notice that it's about the same question; how to get WOT and cruising right. See below my reading. I already turned the main rack adjustment half turn CW. Think I put it back because WOT looks too lean now. What to do about cruising though....
![]()
__________________
72 911E Targa (fun car) BMW 535i Xdrive (work car) Volvo XC90 Ocean Race (family car) VW T2 Riviera Camper van |
||
![]() |
|
Registered
|
Here are few other links that I had stored on my home PC.
Optimum AFR for MFI A/F ratio meter vs. CO meter AFR Readings (LM-2) - Idle speed vs. Partial load MFI main enrichment help Air:Fuel Mixture, MFI Feedback needed Hope they help some.
__________________
72 911 Although it is done at the moment, it will never be finished. |
||
![]() |
|
Moderator
Join Date: Dec 2001
Posts: 9,569
|
__________________
'66 911 #304065 Irischgruen ‘96 993 Carrera 2 Polarsilber '81 R65 Ex-'71 911 PCA C-Stock Club Racer #806 (Sold 5/15/13) Ex-'88 Carrera (Sold 3/29/02) Ex-'91 Carrera 2 Cabriolet (Sold 8/20/04) Ex-'89 944 Turbo S (Sold 8/21/20) |
||
![]() |
|
Registered
|
Thanks guys, a lot of reading to do!
This is my last reading. WOT, uphill (tip of Mark Jung). I think I leave the setting for now until I learned more. The cruising 11-12 still annoys me though.... Ed ![]()
__________________
72 911E Targa (fun car) BMW 535i Xdrive (work car) Volvo XC90 Ocean Race (family car) VW T2 Riviera Camper van |
||
![]() |
|
Registered
|
Your readings are very similar to mine 73 911 E. Your WOT is pretty good. I found max HP to be at 14.5 - 15. I get a miss and possible detonation at 15.5. So a fine line there. At 3k RPM's - Cruising, you are a bit rich. Idle you are rich also. I would add a notch or two of idle lean and a click of the main adjustment toward lean and you should be real close to right on.
Another trick to the trade is to give the linkage to the MFI pump a turn to shorten the rod and thus add lean to the whole spectrum. This is a quick, easy and easily reversible adjustment. The AFR's are pretty cool! Chris 73 911 E |
||
![]() |
|
Moderator
Join Date: Dec 2001
Posts: 9,569
|
Don't monkey with the rod. It throws off everything- the rod must be exactly 114.0 +/- 0.2mm.
__________________
'66 911 #304065 Irischgruen ‘96 993 Carrera 2 Polarsilber '81 R65 Ex-'71 911 PCA C-Stock Club Racer #806 (Sold 5/15/13) Ex-'88 Carrera (Sold 3/29/02) Ex-'91 Carrera 2 Cabriolet (Sold 8/20/04) Ex-'89 944 Turbo S (Sold 8/21/20) |
||
![]() |
|
Registered
|
Very tempting but I won't....
I'll play a bit with the WOT and Idle. Must accept the cruising richness I guess. Ed
__________________
72 911E Targa (fun car) BMW 535i Xdrive (work car) Volvo XC90 Ocean Race (family car) VW T2 Riviera Camper van |
||
![]() |
|
Registered
|
Do what you want, just keep track of everything so you can put it back to where it was. Shortining the linkage to the MFI pump a turn or two will solve your cruising richness issue. Just be mindfull that it will lean the entire specturm. Lean is good. Rich is safe. Too lean is BAD.
Chris 73 911 E |
||
![]() |
|