AFM Adjustment

Carbs & F.I.

Moderators: Amskeptic, Sluggo

Post Reply
User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Posts: 22554
Joined: Sun Apr 02, 2006 8:47 am
Status: Offline

Re: AFM Adjustment

Post by Amskeptic » Wed Jun 01, 2016 5:16 am

Latest post of the previous page:

josebrewin wrote:The bung is just before the catalytic converter in the elbow. It is an Innovate LM-2 wide band sensor. I have an 18 foot cable that brings it into the drivers compartment and it runs on the cigarette lighter. Ordered an SD card so I can record it.
That is way rich, but if it runs / drives, I do not believe that 7.4. Are you calibrated to 20.9 in free air?
( Do you have clean air? :cyclopsani: )
Colin
Deposit Deadline May 13

BobD - 1978 Bus . . . . . . . . . . .110,770 miles
Chloe - 1970 bus . . . . . . . . . . . 206,775 miles
Naranja - 1977 Westfalia . . . . . 76,343 miles
Pluck - 1973 Squareback . . . . . 55,478 miles
Alexus - 1991 Lexus LS400 . . . 69,500 miles

User avatar
asiab3
IAC Addict!
Posts: 1431
Joined: Tue Jan 29, 2013 10:27 pm
Location: California sucks don't move here.
Contact:
Status: Offline

Re: AFM Adjustment

Post by asiab3 » Wed Jun 01, 2016 7:23 am

Amskeptic wrote:
josebrewin wrote:The bung is just before the catalytic converter in the elbow. It is an Innovate LM-2 wide band sensor. I have an 18 foot cable that brings it into the drivers compartment and it runs on the cigarette lighter. Ordered an SD card so I can record it.
That is way rich, but if it runs / drives, I do not believe that 7.4. Are you calibrated to 20.9 in free air?
( Do you have clean air? :cyclopsani: )
Colin
Mine always calibrates to 20.9% O2 readings... Is there an acceptable tolerance for variation?

I too can't seem to drive the car if it ever dips below 10.0:1 AFR.
Robbie
1969 bus, "Buddy"
http://theroadtells.com
"I would not do this again on a short time frame, the country is just so vast and beautiful…" - Barb/Elwood

User avatar
josebrewin
I'm New!
Posts: 7
Joined: Sun May 29, 2016 9:23 pm
Location: Lakewood CA
Status: Offline

Re: AFM Adjustment

Post by josebrewin » Wed Jun 01, 2016 6:36 pm

The AFM reads 20.9 in free air. I get about 13 mpg overall, goes to 65-70 mph on freeway. It shows good at neutral and as soon as it goes in gear the mixture creeps rich. I am going to go to the gold smog place this Friday to see how far off I am. They adjusted the AFM before and it passed with a distributer that didn't advance. New distributor now advances.
Rene Martinez

User avatar
josebrewin
I'm New!
Posts: 7
Joined: Sun May 29, 2016 9:23 pm
Location: Lakewood CA
Status: Offline

Re: AFM Adjustment

Post by josebrewin » Fri Jun 03, 2016 1:15 pm

The smog Mechanic may have found the issue. My Intake sleeve has a crack- vacuum leak, I only checked the hoses for leaks. I re- checked it with starter fluid at home and had a slight rise in acceleration when spraying the right side of the sleeve. I ordered a new sleeve and am back to the drawing board.
Rene Martinez

User avatar
josebrewin
I'm New!
Posts: 7
Joined: Sun May 29, 2016 9:23 pm
Location: Lakewood CA
Status: Offline

Re: AFM Adjustment

Post by josebrewin » Sat Jun 04, 2016 4:22 pm

I removed the intake sleeve and there was a ~ 60 degree crack along the bottom clamp. I replaced the sleeve with a new one and the AFR readings are now much better. 14.7 at idle (1000 rpm) and now at acceleration it is closer to 11 than 7.4. Now need to fine adjust at 15 and 25 mph and see if I can stay above 14 afr.
Rene Martinez

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Posts: 22554
Joined: Sun Apr 02, 2006 8:47 am
Status: Offline

Re: AFM Adjustment

Post by Amskeptic » Mon Jun 20, 2016 4:57 pm

josebrewin wrote:I removed the intake sleeve and there was a ~ 60 degree crack along the bottom clamp. I replaced the sleeve with a new one and the AFR readings are now much better. 14.7 at idle (1000 rpm) and now at acceleration it is closer to 11 than 7.4. Now need to fine adjust at 15 and 25 mph and see if I can stay above 14 afr.
Good job! Why do you want to stay above 14? That is heat-generating lean.
Colin
Deposit Deadline May 13

BobD - 1978 Bus . . . . . . . . . . .110,770 miles
Chloe - 1970 bus . . . . . . . . . . . 206,775 miles
Naranja - 1977 Westfalia . . . . . 76,343 miles
Pluck - 1973 Squareback . . . . . 55,478 miles
Alexus - 1991 Lexus LS400 . . . 69,500 miles

User avatar
josebrewin
I'm New!
Posts: 7
Joined: Sun May 29, 2016 9:23 pm
Location: Lakewood CA
Status: Offline

Re: AFM Adjustment

Post by josebrewin » Tue Jun 28, 2016 9:43 pm

I was just trying it out at smog pass level. Should I run at 13? I am taking it camping this weekend. The alternator ended up needing replacing (12 volts max running and 11Volts with the lights on). Was working on the mustang the last few weeks. Vac leak and replaced drive shaft. Much better now
Rene Martinez

User avatar
josebrewin
I'm New!
Posts: 7
Joined: Sun May 29, 2016 9:23 pm
Location: Lakewood CA
Status: Offline

Re: AFM Adjustment

Post by josebrewin » Sun Jul 03, 2016 4:28 pm

I changed AFM to about 11 and it ran about 10 degrees cooler at the same MPG (~ 13mpg HWY). It felt like it had a little more power also. Leaving it there for now.
Rene Martinez

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Posts: 22554
Joined: Sun Apr 02, 2006 8:47 am
Status: Offline

Re: AFM Adjustment

Post by Amskeptic » Mon Jul 04, 2016 5:55 am

josebrewin wrote:I changed AFM to about 11 and it ran about 10 degrees cooler at the same MPG (~ 13mpg HWY). It felt like it had a little more power also. Leaving it there for now.

Seems counter-intuitive, but I had the same results with my 1978 bus.
Colin
Deposit Deadline May 13

BobD - 1978 Bus . . . . . . . . . . .110,770 miles
Chloe - 1970 bus . . . . . . . . . . . 206,775 miles
Naranja - 1977 Westfalia . . . . . 76,343 miles
Pluck - 1973 Squareback . . . . . 55,478 miles
Alexus - 1991 Lexus LS400 . . . 69,500 miles

DugB
I'm New!
Posts: 12
Joined: Fri Sep 06, 2013 11:20 am
Status: Offline

Re: AFM Adjustment

Post by DugB » Thu Apr 12, 2018 10:01 am

Colin, you piqued my interest in the AFM during your last visit to my place in Falls Church, VA, and because of all of your info at the top of this thread I had the guts to get into mine yesterday. I was pleased to see very intact wiper tracks and a clean interior. I wanted to decrease CHTs a bit when running at higher speeds/loads for sustained periods...just cruising at 65 I'd be pushing 400 degrees with AFR readings around 13.1 (I don't have an Innovate AFR, but rather the one from PLX Devices on which I only ever see ranges from 12 to 13.5, though the engine runs great).

I moved the cog wheel two notches richer, and saw the AFR readings drop by about 0.2 - 0.3 on average. It did result in a bit of a CHT temp drop (maybe 30 degrees on average at highway speeds/loads), with no noticeable impact to performance. I'll run this for a bit, and then try the plug chop some night when I have time. I'm contemplating one more notch richer, just to try it out.

Thanks again!

- Doug

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Posts: 22554
Joined: Sun Apr 02, 2006 8:47 am
Status: Offline

Re: AFM Adjustment

Post by Amskeptic » Mon Apr 16, 2018 8:19 am

DugB wrote:
Thu Apr 12, 2018 10:01 am
Colin, you piqued my interest in the AFM during your last visit to my place in Falls Church, VA, and because of all of your info at the top of this thread I had the guts to get into mine yesterday. I was pleased to see very intact wiper tracks and a clean interior. I wanted to decrease CHTs a bit when running at higher speeds/loads for sustained periods...just cruising at 65 I'd be pushing 400 degrees with AFR readings around 13.1 (I don't have an Innovate AFR, but rather the one from PLX Devices on which I only ever see ranges from 12 to 13.5, though the engine runs great).

I moved the cog wheel two notches richer, and saw the AFR readings drop by about 0.2 - 0.3 on average. It did result in a bit of a CHT temp drop (maybe 30 degrees on average at highway speeds/loads), with no noticeable impact to performance. I'll run this for a bit, and then try the plug chop some night when I have time. I'm contemplating one more notch richer, just to try it out.

Thanks again!

- Doug
How do you like your PLX a/f reader?
Colin
Deposit Deadline May 13

BobD - 1978 Bus . . . . . . . . . . .110,770 miles
Chloe - 1970 bus . . . . . . . . . . . 206,775 miles
Naranja - 1977 Westfalia . . . . . 76,343 miles
Pluck - 1973 Squareback . . . . . 55,478 miles
Alexus - 1991 Lexus LS400 . . . 69,500 miles

DugB
I'm New!
Posts: 12
Joined: Fri Sep 06, 2013 11:20 am
Status: Offline

Re: AFM Adjustment

Post by DugB » Mon Apr 16, 2018 8:27 am

Well, because everyone seems to be using the Innovate meter, and the PLX figures for comparison don't seem to be in the same ballpark, I just ordered an LC-2 to install. Now that I've been into the AFM, and understand the adjustments possible a bit more due to this (and other) threads, I want numbers I can actually compare with others.

As for the PLX all by itself, it has not been trouble-free. There have been long periods of time where the meter seemed to still be working (due to the colored lights still responding), but the center section would not show the AFR reading value after the start up sequence. There is no data output, so I can't do anything with the data being generated. The installation also doesn't seem as easy as the LC-2, either. That said, I have never experienced the O sensor woes that some LM-1/LM-2/LC-1/LC-2 customers have reported.

I'll let you know more fully after I have a chance to install the LC-2. :-)

- Doug

Post Reply

Return to “Fuel Delivery”

Who is online

Users browsing this forum: No registered users and 1 guest