 Air/Fuel ratio, is there a quick answer? |
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| malcolm2 |
 Feb 5 2017, 05:50 PM
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Advanced Member  Group: Members Posts: 2,738 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States 
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OK, I have been tinkering with the new-to-me AFM on my 1911cc engine all weekend. I have adjusted the spring about 20 teeth CCW to get to this point.
I have been using an A/F sensor and gauge. can someone tell me, or direct me to a chart/table of what A/F I should be shooting for on my daily driver. The last adjustment of the CO screw has left me here: I have always had a strange idle situation, so lets ignore that for now. any normal adjustments to reduce the idle at normal operating temp eventually stall the car. A problem for another post. (IMG:style_emoticons/default/blink.gif) the idle is high.... at 1200 the A/F is a smooth 12.2. I found a long hill and drove up it at about 3800 rpm and the A/F was 12.5. thoughts? |
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Posts in this topic
malcolm2 Air/Fuel ratio Feb 5 2017, 05:50 PM
jim_hoyland Got this from one of Chris Foley's posts
in A... Feb 5 2017, 06:09 PM malcolm2 Great. I get to drive to work tomorrow (no rain). ... Feb 5 2017, 06:34 PM jim_hoyland My experience ( before and after the top end rebui... Feb 5 2017, 07:37 PM pbanders Agree with the ranges in Jim's posts for varyi... Feb 5 2017, 10:22 PM ottox914 Getting idle and AFR can be a challenge. As the en... Feb 5 2017, 10:34 PM plays with cars Peak power is made around 13.5:1, idle is usually ... Feb 6 2017, 12:10 AM Mark Henry I don't like to see much higher than 13:1 in a... Feb 6 2017, 12:40 AM
Mueller
I don't like to see much higher than 13:1 in ... Feb 10 2017, 03:52 PM Mark Henry
[quote name='Mark Henry' post='2451811' date='Feb... Feb 10 2017, 06:19 PM timothy_nd28 :agree: Aircooled engines may need to run slight... Feb 6 2017, 09:41 AM 72hardtop
:agree: Aircooled engines may need to run sligh... Oct 29 2018, 02:29 AM Keith914 When in doubt, do the spark plug color test. Feb 6 2017, 10:45 AM Mark Henry
When in doubt, do the spark plug color test.
I s... Feb 6 2017, 12:31 PM porschetub Doing final tune on my Zeniths,dropping idles down... Feb 6 2017, 02:12 PM Mark Henry
Mark what is the best performing/value AFR kit t... Feb 6 2017, 05:13 PM porschetub
Mark what is the best performing/value AFR kit ... Feb 6 2017, 07:38 PM malcolm2 Help me out with WOT. I played with that a little... Feb 6 2017, 03:04 PM timothy_nd28 I think it would be a cool gauge to have. Would i... Feb 6 2017, 07:05 PM Mark Henry
I think it would be a cool gauge to have. Would ... Feb 6 2017, 11:06 PM Porschef It's a great tool to have, especially if you... Feb 7 2017, 05:21 AM McMark Peak power is made around 13.5:1, ....That's t... Feb 7 2017, 11:31 AM ConeDodger
Peak power is made around 13.5:1, ....That's ... Feb 7 2017, 11:46 AM Mark Henry
[quote name='McMark' post='2452311' date='Feb 7 2... Feb 7 2017, 12:05 PM malcolm2
But on top of the WB meter you should have a head... Feb 7 2017, 02:18 PM timothy_nd28 350 degrees is not normal, atleast I hope not. Re... Feb 7 2017, 08:47 PM malcolm2
350 degrees is not normal, atleast I hope not. R... Feb 8 2017, 11:32 AM malcolm2
350 degrees is not normal, atleast I hope not. R... Feb 8 2017, 12:02 PM Vacca Rabite
350 degrees is not normal, atleast I hope not. R... Apr 27 2017, 09:13 AM malcolm2
I'd love to see 350 at 70MPH running up some ... Apr 28 2017, 06:29 AM ConeDodger The good thing about a CHT gauge is you know your ... Feb 7 2017, 08:51 PM Mark Henry
The good thing about a CHT gauge is you know your... Feb 8 2017, 07:33 AM malcolm2
The good thing about a CHT gauge is you know you... Feb 8 2017, 11:37 AM djway When I set up my L jet that had been horribly mess... Feb 8 2017, 10:11 PM malcolm2
When I set up my L jet that had been horribly mes... Feb 9 2017, 10:15 AM djway You are running WAY to rich. At full throttle onl... Feb 9 2017, 08:45 PM jcd914 If your air flow meter has been mucked with alread... Feb 10 2017, 12:55 AM falcor75
Stoic for gasoline is 15.8
Ummm, I dont know ... Feb 10 2017, 01:34 AM djway
Stoic for gasoline is 15.8
Ummm, I dont know... Feb 10 2017, 04:07 AM Mark Henry If you are running at stoich AFR on an aircooled y... Feb 10 2017, 10:03 AM malcolm2 On WOT are you documenting at bottom value? I ten... Feb 10 2017, 11:41 AM malcolm2
On WOT are you documenting at bottom value? I te... Feb 14 2017, 01:30 PM Porschef Clark, are you referring to the screw on the AFM i... Feb 10 2017, 11:56 AM malcolm2
Clark, are you referring to the screw on the AFM ... Feb 10 2017, 03:21 PM Porschef Mark, i get the nickies can deal with a leaner mix... Feb 10 2017, 11:58 AM Porschef IIRC, I'm at 13.2 or so at cruise. The engine ... Feb 10 2017, 12:06 PM malcolm2
Of course, there shall be no vacuum leaks...
... Feb 10 2017, 03:26 PM timothy_nd28 If you have smoke coming out from the dizzy, you w... Feb 10 2017, 04:10 PM malcolm2
If you have smoke coming out from the dizzy, you ... Feb 10 2017, 04:58 PM timothy_nd28 AA is now closed, so now your thinking RTV? :D
... Feb 10 2017, 05:23 PM malcolm2
AA is now closed, so now your thinking RTV? :D
... Feb 11 2017, 08:37 AM Mark Henry Just a FYI, PLX has their O2 WB meters on sale ... Feb 10 2017, 06:24 PM malcolm2
Just a FYI, PLX has their O2 WB meters on sale ... Feb 11 2017, 08:33 AM Mark Henry
[quote name='Mark Henry' post='2453440' date='Feb... Feb 11 2017, 10:16 AM timothy_nd28 Those numbers are better than the 18+ numbers you ... Feb 14 2017, 01:47 PM malcolm2
Those numbers are better than the 18+ numbers you... Feb 14 2017, 02:37 PM stugray Any leaks coming from the valve cover, dipstick, o... Feb 14 2017, 02:40 PM timothy_nd28 You tell yourself that while trying to start a Lje... Feb 14 2017, 03:26 PM pete000 Great read, I am in the exact situation with my 1.... Feb 14 2017, 04:29 PM malcolm2 No adjustments or significant changes to the readi... Feb 24 2017, 10:14 AM timothy_nd28 I think your old bent AFM was adjusted abit rich. Feb 24 2017, 10:33 AM malcolm2
I think your old bent AFM was adjusted abit rich.... Feb 24 2017, 01:01 PM malcolm2 Mark, I have been studying up on your AFR link fro... Feb 24 2017, 01:04 PM veekry9 No quick answers,because it's complicated,many... Feb 24 2017, 03:53 PM pete000 I picked up one of the PLX Blue Tooth AFR systems ... Mar 5 2017, 12:56 AM Mark Henry Yes 15:1 cruise is too lean for an aircooled 14:1 ... Mar 5 2017, 07:55 AM 72hardtop
Yes 15:1 cruise is too lean for an aircooled 14:1... Apr 24 2017, 05:49 AM McMark I agree with and support everything Mark Henry has... Mar 5 2017, 09:46 AM malcolm2 My PLX rig showed up Friday. Looking forward to ge... Mar 5 2017, 08:01 PM pete000
My PLX rig showed up Friday. Looking forward to g... Mar 6 2017, 11:20 PM timothy_nd28 Be careful. The air flow meter has a wound up clo... Mar 7 2017, 11:22 AM malcolm2
Be careful. The air flow meter has a wound up cl... Mar 7 2017, 02:16 PM pete000 Sounds like these early FI cars are set from the f... Mar 7 2017, 10:59 PM malcolm2 I do like welding stuff.... but man you can screw ... Mar 10 2017, 02:30 PM Mark Henry Was your wire feed sticking?
You likely need a new... Mar 10 2017, 03:04 PM malcolm2
Was your wire feed sticking?
You likely need a ne... Mar 10 2017, 03:10 PM malcolm2 PLX is now installed. The guage is temp'd in w... Mar 23 2017, 09:55 AM pete000 I have been playing around a bit with my AFM. I ha... Mar 23 2017, 06:57 PM malcolm2 My AFM has that jumper. Did not know it was an add... Mar 24 2017, 06:22 AM malcolm2 5 hours of interstate driving. Several big hills. ... Mar 24 2017, 06:23 AM Porschef Hey Clark,
PM sent
Joe Mar 24 2017, 07:50 AM timothy_nd28 Sounds like you are around 26 mpg. I think with t... Mar 24 2017, 10:15 AM timothy_nd28 I take back what I said. Maybe you are already ge... Mar 24 2017, 10:48 AM pete000 Tested out my AFM mods and seemed to work well. Wa... Mar 24 2017, 04:49 PM malcolm2 I made it home.... 800 + mile weekend trip. I don... Mar 27 2017, 03:16 PM malcolm2 Ok what do you think? Maybe 1000 miles with this ... Mar 27 2017, 04:33 PM 72hardtop
Ok what do you think? Maybe 1000 miles with this... Oct 29 2018, 02:19 AM timothy_nd28 I got nothing. My work with you is done. Mar 27 2017, 05:10 PM Mark Henry I'd say that plug is a tad hot, what number is... Mar 27 2017, 05:17 PM malcolm2
I'd say that plug is a tad hot, what number i... Mar 27 2017, 07:11 PM Olympic 1.7 Spark plugs are an easy change, you could try NGK ... Mar 28 2017, 07:55 AM 72hardtop This is a great graph for air cooled engines:
htt... Apr 24 2017, 05:38 AM jpapatrout I just saw an ad for an AFR from Innovate that mon... May 6 2017, 04:24 PM 914Toy
I just saw an ad for an AFR from Innovate that mo... Nov 1 2018, 09:13 AM Chi-town There is no "short answer" for this ques... Oct 29 2018, 10:36 AM 72hardtop
There is no "short answer" for this que... Nov 1 2018, 12:04 AM  |
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