 What's your A/F on Overrun?, 'Nother D-Jet A/F Question |
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| BeatNavy |
 Mar 12 2017, 12:28 PM
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#1
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Certified Professional Scapegoat  Group: Members Posts: 2,924 Joined: 26-February 14 From: Easton, MD Member No.: 17,042 Region Association: MidAtlantic Region 
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For those with D-Jet, what are you typically seeing for A/F ratio on a medium to hard overrun? Based on what I've read here mine seems too rich - like in 10's and 11's. Once the RPM's drop closer to idle it bounces back up to normal idle A/F ratios. Does A/F on overrun even matter?
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| Mark Henry |
Aug 15 2017, 08:11 AM
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#2
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
QUOTE(BeatNavy @ Mar 12 2017, 02:28 PM)  Does A/F on overrun even matter? Overrun and AFR means diddly squat. No load, it doesn't matter how lean it is. I have complete fuel cut on my programmable FI, you can't get leaner than that, it's never hurt anything. |
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| Olympic 914 |
Aug 15 2017, 09:23 AM
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#3
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Group: Members Posts: 1,668 Joined: 7-July 11 From: Pittsburgh PA Member No.: 13,287 Region Association: North East States
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QUOTE(Mark Henry @ Aug 15 2017, 10:11 AM) QUOTE(BeatNavy @ Mar 12 2017, 02:28 PM) Does A/F on overrun even matter? Overrun and AFR means diddly squat. No load, it doesn't matter how lean it is. I have complete fuel cut on my programmable FI, you can't get leaner than that, it's never hurt anything. If it were lean I wouldn't worry about it, but its real rich in the 10.0 + range. So somehow it is dumping fuel in there. it may even be worse but my low reading limit on the Autometer AFR is set a 10.0 granted I have not put many miles on this engine and am still sorting things out but after following a truck down a long hill with it going rich, when the truck stopped at the bottom of the hill to make a turn and I had to stop behind it, the engine just quit... it did start right up again, but since I am looking for problems this might be one. Engine is a 2056 w/ Raby 9590 cam and Ham's RS+ heads, SS HEs and a Triad muffler. ECU 037 |
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| Mark Henry |
Aug 15 2017, 11:31 AM
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#4
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
QUOTE(Olympic 914 @ Aug 15 2017, 11:23 AM) QUOTE(Mark Henry @ Aug 15 2017, 10:11 AM) QUOTE(BeatNavy @ Mar 12 2017, 02:28 PM) Does A/F on overrun even matter? Overrun and AFR means diddly squat. No load, it doesn't matter how lean it is. I have complete fuel cut on my programmable FI, you can't get leaner than that, it's never hurt anything. If it were lean I wouldn't worry about it, but its real rich in the 10.0 + range. So somehow it is dumping fuel in there. it may even be worse but my low reading limit on the Autometer AFR is set a 10.0 granted I have not put many miles on this engine and am still sorting things out but after following a truck down a long hill with it going rich, when the truck stopped at the bottom of the hill to make a turn and I had to stop behind it, the engine just quit... it did start right up again, but since I am looking for problems this might be one. Engine is a 2056 w/ Raby 9590 cam and Ham's RS+ heads, SS HEs and a Triad muffler. ECU 037 Oh sorry, brain fart...guess I should read things better. (IMG:style_emoticons/default/smile.gif) My first guess is it isn't dumping any more fuel in, just you cut off the air so it makes the charge rich. I'd say it doesn't have any fuel cut at all, I don't know if that is normal for D-jet or not. I do know L-jet definitely has a fuel reduction, but not a total fuel cut. |
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Posts in this topic
BeatNavy What's your A/F on Overrun? Mar 12 2017, 12:28 PM
mgphoto
For those with D-Jet, what are you typically seei... Mar 12 2017, 04:23 PM BeatNavy Good. No popping, if that's what you're a... Mar 12 2017, 04:44 PM
mgphoto
Good. No popping, if that's what you're ... Mar 12 2017, 05:22 PM BeatNavy Not particularly. That's sort of been the roo... Mar 12 2017, 06:13 PM mgphoto
Not particularly. That's sort of been the ro... Mar 12 2017, 11:55 PM BeatNavy
The issue is not your temp sensor, it's the m... Mar 13 2017, 03:41 AM brant
Not particularly. That's sort of been the ro... Mar 13 2017, 12:19 PM falcor75 Could leaking injectors cause your WB to read rich... Mar 13 2017, 04:23 AM r_towle have you ever replaced the cold start injector? Th... Mar 13 2017, 11:16 AM BeatNavy
have you ever replaced the cold start injector? T... Mar 13 2017, 12:07 PM BeatNavy I did some more looking around today, and I think ... Mar 19 2017, 11:06 AM BeatNavy
I'll probably also try plugging off the cold ... Mar 19 2017, 12:29 PM nordfisch
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Not sure if the higher vacuum level at higher... Sep 29 2018, 03:47 PM Olympic 914 Did you ever find out any more about this ?
I am ... Aug 15 2017, 06:05 AM Frank S
Did you ever find out any more about this ?
I am... Sep 27 2018, 10:03 AM BeatNavy No, not really. I did refurb the throttle body so... Aug 15 2017, 06:50 AM saigon71 I can't speak to your A/F on overrun. I had my... Aug 15 2017, 07:18 AM Philip W. My AF seems to stay around 12.-12.5 I believe - de... Aug 15 2017, 07:32 AM BeatNavy Good question, Bob. In my case I am running stock... Aug 15 2017, 07:36 AM 914_teener It depends on the ecu for fuel cut off. Aug 15 2017, 11:39 AM Mark Henry
It depends on the ecu for fuel cut off.
But it w... Aug 15 2017, 11:47 AM 914_teener
It depends on the ecu for fuel cut off.
But it ... Aug 15 2017, 11:57 AM barefoot IIRC D-jet is designed to cut off fuel on closed t... Aug 15 2017, 11:48 AM BeatNavy My understanding is that the TPS detects an idle s... Aug 15 2017, 12:17 PM 914_teener
My understanding is that the TPS detects an idle ... Aug 15 2017, 12:36 PM Philip W.
My understanding is that the TPS detects an idle... Aug 15 2017, 01:46 PM 914_teener
[quote name='914_teener' post='2517302' date='Aug... Aug 15 2017, 01:58 PM Olympic 914 Rob
What ECU are you running?
You said that yo... Aug 15 2017, 12:29 PM BeatNavy
Rob
What ECU are you running?
You said that y... Aug 15 2017, 12:36 PM BeatNavy Just closing the loop. I actually have an 044 ECU... Aug 15 2017, 04:59 PM Dave_Darling Very early cars would cut fuel on overrun, but tha... Aug 15 2017, 08:19 PM Mark Henry I can't see a system that has no fuel cut havi... Aug 16 2017, 08:28 AM Philip W. Mark I agree, this is what I was seeing and why I ... Aug 16 2017, 09:00 AM Mark Henry I was thinking more on what Dave said, although th... Aug 16 2017, 09:12 AM mgphoto According to Porsche/VW the fuel cut off caused th... Aug 17 2017, 07:19 PM BeatNavy I played around with my MPS, decal valve, tuning a... Sep 27 2018, 11:20 AM Olympic 914
I played around with my MPS, decal valve, tuning ... Sep 27 2018, 04:03 PM BeatNavy
I played around with my MPS, decal valve, tuning... Sep 28 2018, 05:48 AM Frank S AFR of 12 will not hurt the engine and is reasonab... Sep 27 2018, 11:50 AM BeatNavy
AFR of 12 will not hurt the engine and is reasona... Sep 27 2018, 12:03 PM Frank S
AFR of 12 will not hurt the engine and is reason... Sep 27 2018, 12:09 PM cgnj Hi,
just saw this. A while ago I had a PM exchange... Sep 27 2018, 03:18 PM |
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