 air fuel ratio meters, Anyone have much experience using these on D-Jet |
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| 914Mels |
 Jul 4 2011, 02:07 PM
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#1
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Member  Group: Members Posts: 357 Joined: 20-June 11 From: Santee Member No.: 13,221 Region Association: Southern California  |
(IMG:style_emoticons/default/sawzall-smiley.gif) I'm looking to fine tune the injection on my '70 914 and am considering a LM-1 meter to take out the guess work. Has anyone done much work with one of these? Or suggest a different model meter?
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Replies(1 - 19)
| Mike Bellis |
Jul 4 2011, 03:57 PM
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#2
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Resident Electrician Group: Members Posts: 8,348 Joined: 22-June 09 From: Midlothian TX Member No.: 10,496 Region Association: None 
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The LM-1 is a good unit. AEM and Autometer make them too with gauges to mount on the dash. Not much fine tuning can be done on early FI systems. You can tune it but not fine tune it. The system runs on internal fuel maps and they are not accessible.
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| Dave_Darling |
Jul 4 2011, 04:23 PM
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#3
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914 Idiot Group: Members Posts: 15,335 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California
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Heh, the system doesn't even rely on fuel maps at all! It uses the amount of time for an electric current to induce a current in another coil of wire (inductive coupling) as the basic metering time!
Read up at http://members.rennlist.com/pbanders -- Brad Anders has a lot of D-jet info, including suggestions about ways that it can be tweaked and possibly (if you're lucky) tuned. --DD |
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| 914Mels |
Jul 4 2011, 04:56 PM
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#4
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Member Group: Members Posts: 357 Joined: 20-June 11 From: Santee Member No.: 13,221 Region Association: Southern California |
QUOTE(kg6dxn @ Jul 4 2011, 02:57 PM)  The LM-1 is a good unit. AEM and Autometer make them too with gauges to mount on the dash. Not much fine tuning can be done on early FI systems. You can tune it but not fine tune it. The system runs on internal fuel maps and they are not accessible. Thanks for the reply, I wasn't sure who would be here on the 4th. The 914 monkey on my back won't let up, holiday or not. I want to fool the ICU, fuel pressure up or down, experiment with some variable resistors for the temp senders to get closer to a better mixture. I'm hoping to "see" where the engines at and not create any problems just randomly modifing and hoping for a improvement. |
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| brant |
Jul 4 2011, 05:45 PM
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#5
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914 Wizard Group: Members Posts: 12,167 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains
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I've used an LM-1 to adjust MPS units to fit the motor
also if you planned on tweeking resistors, or fuel pressure, the LM-1 would give you a good picture of which way and how far you were going..... |
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| Strudelwagon |
Jul 4 2011, 05:56 PM
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#6
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Member Group: Members Posts: 411 Joined: 11-October 08 From: interior, British Columbia Member No.: 9,633 Region Association: Canada |
QUOTE(Dave_Darling @ Jul 4 2011, 03:23 PM) Heh, the system doesn't even rely on fuel maps at all! It uses the amount of time for an electric current to induce a current in another coil of wire (inductive coupling) as the basic metering time! Read up at http://members.rennlist.com/pbanders -- Brad Anders has a lot of D-jet info, including suggestions about ways that it can be tweaked and possibly (if you're lucky) tuned. --DD When I got my 2.0 a few years ago the PO had installed a little reostat with toggle switch that I believe can richen or lean out the fuel. Some old autocrosser black magic?? Wired directly to the ECU. SW |
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| 914Mels |
Jul 4 2011, 06:00 PM
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#7
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Member Group: Members Posts: 357 Joined: 20-June 11 From: Santee Member No.: 13,221 Region Association: Southern California |
QUOTE(brant @ Jul 4 2011, 04:45 PM) I've used an LM-1 to adjust MPS units to fit the motor also if you planned on tweeking resistors, or fuel pressure, the LM-1 would give you a good picture of which way and how far you were going..... Yeah, that's what I'm trying for. The injection is stock, 1.7, the motor has 93's from a 1.8 and the cam is a unknown hydraulic grind that was put in years ago. So I figure the original fuel map is probably off a bit. Once I get this rolling, I'll post some results. Anyone have a gently used meter for sale? |
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| brant |
Jul 4 2011, 06:00 PM
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#8
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914 Wizard Group: Members Posts: 12,167 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains
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its been done a lot
but the wideband will tell you how much to turn the knob AFR isn't like a boost knob there is a range and its not a wide one, where it will run right beyond that you loose HP, and on the lean side you do damage... really once you get it dialed in you should leave it alone. if you were going to tune for altitude, humidity (beyond the factory compensation) you would need the wideband to see what you were doing. brant |
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| 914Mels |
Jul 4 2011, 06:36 PM
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#9
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Member Group: Members Posts: 357 Joined: 20-June 11 From: Santee Member No.: 13,221 Region Association: Southern California |
QUOTE(brant @ Jul 4 2011, 05:00 PM) its been done a lot but the wideband will tell you how much to turn the knob AFR isn't like a boost knob there is a range and its not a wide one, where it will run right beyond that you loose HP, and on the lean side you do damage... really once you get it dialed in you should leave it alone. if you were going to tune for altitude, humidity (beyond the factory compensation) you would need the wideband to see what you were doing. brant That's the plan, get the modifications dialed in and replace the variables with some fixed resistors. Thanks to everyone who chimed in, I will have a beer in your honor. (IMG:style_emoticons/default/beer3.gif) Mike |
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| ConeDodger |
Jul 4 2011, 08:40 PM
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#10
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Apex killer! Group: Members Posts: 24,396 Joined: 31-December 04 From: Tahoe Area Member No.: 3,380 Region Association: Northern California
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Remember to sample under load. Neutral revving numbers are no bueno...
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| 914_teener |
Jul 5 2011, 11:03 AM
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#11
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914 Guru Group: Members Posts: 5,270 Joined: 31-August 08 From: So. Cal Member No.: 9,489 Region Association: Southern California |
QUOTE(914Mels @ Jul 4 2011, 05:00 PM) QUOTE(brant @ Jul 4 2011, 04:45 PM) I've used an LM-1 to adjust MPS units to fit the motor also if you planned on tweeking resistors, or fuel pressure, the LM-1 would give you a good picture of which way and how far you were going..... Yeah, that's what I'm trying for. The injection is stock, 1.7, the motor has 93's from a 1.8 and the cam is a unknown hydraulic grind that was put in years ago. So I figure the original fuel map is probably off a bit. Once I get this rolling, I'll post some results. Anyone have a gently used meter for sale? This is interesting. I would be very interested in your results. I was thinking of doing the same. |
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| sean_v8_914 |
Jul 5 2011, 11:22 AM
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#12
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Chingon 601 Group: Members Posts: 4,011 Joined: 1-February 05 From: San Diego Member No.: 3,541 |
LM1 can be found at a discount since they came out with LM2 in color
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| 914Mels |
Jul 5 2011, 11:38 AM
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#13
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Member Group: Members Posts: 357 Joined: 20-June 11 From: Santee Member No.: 13,221 Region Association: Southern California |
QUOTE(914_teener @ Jul 5 2011, 10:03 AM) QUOTE(914Mels @ Jul 4 2011, 05:00 PM) QUOTE(brant @ Jul 4 2011, 04:45 PM) I've used an LM-1 to adjust MPS units to fit the motor also if you planned on tweeking resistors, or fuel pressure, the LM-1 would give you a good picture of which way and how far you were going..... Yeah, that's what I'm trying for. The injection is stock, 1.7, the motor has 93's from a 1.8 and the cam is a unknown hydraulic grind that was put in years ago. So I figure the original fuel map is probably off a bit. Once I get this rolling, I'll post some results. Anyone have a gently used meter for sale? This is interesting. I would be very interested in your results. I was thinking of doing the same. I'm pricing meters, found one on Amazon for $229. That seems pretty fair for what you get. I'm glad I found this web site, there is a ton of info here that isn't easily available out of a repair manual. I've spent some time checking all the basics out first, to get a true baseline. Had a leaky MAP sensor and one dead plug wire resistor. We'll see how far off things are from here. Mike (IMG:style_emoticons/default/driving.gif) |
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| Maltese Falcon |
Jul 5 2011, 09:38 PM
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#14
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914 Guru Group: Members Posts: 5,209 Joined: 14-September 04 From: Mulholland SoCal Member No.: 2,755 Region Association: None |
Mike, I'm using the unit from Nordskog Instruments . It's easy to install and has a 2 1/16" gauge face , you can put it just about anywhere. I mounted it off of the knee bar on the roll cage.
Marty |
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| brant |
Jul 5 2011, 10:59 PM
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#15
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914 Wizard Group: Members Posts: 12,167 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains
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nordskog makes some good stuff
and their customer-tech service is top notch I have a bunch of their stuff in one car: also.. Innovate makes a great AFR I've run it for years now... Attached thumbnail(s)   Attached image(s) 
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| 914Mels |
Jul 6 2011, 05:44 PM
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#16
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Member Group: Members Posts: 357 Joined: 20-June 11 From: Santee Member No.: 13,221 Region Association: Southern California |
I like your dash install, I'm not sure I want to permamently mount one in the car. If I can see the readings all the time while I'm driving, I may drive myself crazy trying to "perfect" every load and driving condition. I'm hoping to spend a few hours at a time and dial in the worst of the results untill I run out of options. Thanks to everyone for all the imput.
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| Mike Bellis |
Jul 6 2011, 07:42 PM
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#17
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Resident Electrician Group: Members Posts: 8,348 Joined: 22-June 09 From: Midlothian TX Member No.: 10,496 Region Association: None
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QUOTE(914Mels @ Jul 6 2011, 04:44 PM) I like your dash install, I'm not sure I want to permamently mount one in the car. If I can see the readings all the time while I'm driving, I may drive myself crazy trying to "perfect" every load and driving condition. I'm hoping to spend a few hours at a time and dial in the worst of the results untill I run out of options. Thanks to everyone for all the imput. Don't worry. You wont be able to perfect the factory FI. You will need to switch to a programmable EFI system to get the desired results. |
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| 914_teener |
Jul 6 2011, 11:17 PM
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#18
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914 Guru Group: Members Posts: 5,270 Joined: 31-August 08 From: So. Cal Member No.: 9,489 Region Association: Southern California |
QUOTE(kg6dxn @ Jul 6 2011, 06:42 PM) QUOTE(914Mels @ Jul 6 2011, 04:44 PM) I like your dash install, I'm not sure I want to permamently mount one in the car. If I can see the readings all the time while I'm driving, I may drive myself crazy trying to "perfect" every load and driving condition. I'm hoping to spend a few hours at a time and dial in the worst of the results untill I run out of options. Thanks to everyone for all the imput. Don't worry. You wont be able to perfect the factory FI. You will need to switch to a programmable EFI system to get the desired results. What FI system would you suggest? |
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| Mark Henry |
Jul 7 2011, 09:21 AM
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#19
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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 |
Just an FYI this is the JAW wideband, it's a DIY kit. $140 plus $50 for the bosch O2 sender.
http://14point7.com/SLC-DIY-2.php |
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| Bleyseng |
Jul 7 2011, 11:25 AM
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#20
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Aircooled Baby! Group: Members Posts: 13,037 Joined: 27-December 02 From: Seattle, Washington (for now) Member No.: 24 Region Association: Pacific Northwest |
Factory Djet is close enough for a hydro cam 914..as the cam timing is mucked up by the ramps compared to a solid lifter cam which has better cam timing.
use the LM1 to set the "partload" to 13.5/14 to 1 AFR at 2500rpms driving at a steady speed up a long slight uphill road in 3rd gear. Check it at freeway speeds to get it to hang around 13.5/14 driving in 5th gear at speed up slight slopes as if you are coasting (off throttle) its no good. You want a steady throttle at a steady speed with slight load. Then check the Wide open throttle settings- those should be in third gear at 10-15mph punch it and see. It should start at 11/11.5 to 1 to start and all the way up to 5000 rpms slowly lean out to 13.5 to 1. This is adjusted with the large machined plug witch you have to remove undamaged to get to the inner screws to adjust the part load. Finally, check the idle as it should be to 13.5 to 1..... First off, make sure the engine is in top tune, valves adjusted, no vacuum leaks and Fuel pressure adjusted to 29lbs. |
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