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> Question for the L Jet Gang, If you could choose...
djway
post Apr 11 2020, 11:47 PM
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OK L Jet people, if you could choose between an L Jet system that consisted of the 6 pin AFM and a 74 Brain or a 7 pin AFM and a 76 Brain which would you choose and why?
Discuss. (IMG:style_emoticons/default/smile.gif)
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ClayPerrine
post Apr 12 2020, 07:32 AM
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QUOTE(djway @ Apr 12 2020, 12:47 AM) *

OK L Jet people, if you could choose between an L Jet system that consisted of the 6 pin AFM and a 74 Brain or a 7 pin AFM and a 76 Brain which would you choose and why?
Discuss. (IMG:style_emoticons/default/smile.gif)


The only difference between the two is the location of the air temp sender. Basically they are interchangeable. I would pick the one that works the best.

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djway
post Apr 12 2020, 03:47 PM
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QUOTE(ClayPerrine @ Apr 12 2020, 06:32 AM) *

QUOTE(djway @ Apr 12 2020, 12:47 AM) *

OK L Jet people, if you could choose between an L Jet system that consisted of the 6 pin AFM and a 74 Brain or a 7 pin AFM and a 76 Brain which would you choose and why?
Discuss. (IMG:style_emoticons/default/smile.gif)


The only difference between the two is the location of the air temp sender. Basically they are interchangeable. I would pick the one that works the best.

Thanks. I had wondered if the 75/76 may have different parameters than the 74.
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r_towle
post Apr 12 2020, 09:58 PM
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Well, one has 6 pins and one has 7 pins
More is better
7 is a lucky number.

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djway
post Apr 12 2020, 10:36 PM
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The seventh pin is a direct line to the temp sensor and does not share a line like the others. I checked and all the temp sensors are in the same exact location below the circuitboard or a.k.a. potentiometer.
Isn’t seven craps?
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ejm
post Apr 13 2020, 05:13 AM
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QUOTE(djway @ Apr 12 2020, 01:47 AM) *

OK L Jet people, if you could choose between an L Jet system that consisted of the 6 pin AFM and a 74 Brain or a 7 pin AFM and a 76 Brain which would you choose and why?
Discuss. (IMG:style_emoticons/default/smile.gif)


Trick question. L-jet wasn't used on the '76 914.
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ClayPerrine
post Apr 13 2020, 06:36 AM
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QUOTE(ejm @ Apr 13 2020, 06:13 AM) *

QUOTE(djway @ Apr 12 2020, 01:47 AM) *

OK L Jet people, if you could choose between an L Jet system that consisted of the 6 pin AFM and a 74 Brain or a 7 pin AFM and a 76 Brain which would you choose and why?
Discuss. (IMG:style_emoticons/default/smile.gif)


Trick question. L-jet wasn't used on the '76 914.



Nope. 76 model cars were all 2.0L cars with D-Jet.

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djway
post Aug 22 2020, 12:22 AM
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Tracking down issue on why the motor won't start.
Does the pump always stay on? I know the yellow wire powers the pump during cranking then the AFM takes over when key released, but, does the pumps always remain on.
I see nothing that would shut it off if it reached a certain pressure but I don't want to assume.
The first time I turned the motor on it instantly fired which startled me and I shut it off. Tried again and got a short burst then nothing after that.
Intermittently I could hear the pump run and sometimes nothing. Sometimes the starter would crank and other times nothing.
The timing light said the wires were getting juice so I am pretty sure it is fuel delivery and probably more than one wire connection.
I have a few wires I suspect may have been damaged with all the ins and outs I had to put the motor through getting things to fit in the Notchback.
Hey, at least it didn't explode (IMG:style_emoticons/default/beer.gif)
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porschetub
post Aug 22 2020, 11:11 PM
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QUOTE(djway @ Aug 22 2020, 06:22 PM) *

Tracking down issue on why the motor won't start.
Does the pump always stay on? I know the yellow wire powers the pump during cranking then the AFM takes over when key released, but, does the pumps always remain on.
I see nothing that would shut it off if it reached a certain pressure but I don't want to assume.
The first time I turned the motor on it instantly fired which startled me and I shut it off. Tried again and got a short burst then nothing after that.
Intermittently I could hear the pump run and sometimes nothing. Sometimes the starter would crank and other times nothing.
The timing light said the wires were getting juice so I am pretty sure it is fuel delivery and probably more than one wire connection.
I have a few wires I suspect may have been damaged with all the ins and outs I had to put the motor through getting things to fit in the Notchback.
Hey, at least it didn't explode (IMG:style_emoticons/default/beer.gif)


I'am getting my head around these systems as my experience is with later systems like Dijifant and Motronic,but my next build will be on a 914 96mm L-jet based on an early 1700 FI case so I'am schooling up.
My understanding is upon cranking the AFM air gate moves and the pump starts in response to that and it only shuts of via the key in off position ?.
I seem to remember someone saying the double relay system if wired wrong or wrong relay can cause the pump to constant run with the key on.
I would look @ your ignition switch or the pump ,both don't last for ever.
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djway
post Aug 22 2020, 11:46 PM
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I believe I had/have multiple issues.
I replaced the yellow wire fitting onto the relay as it seemed weak, fragile.
After that I was concerned that the ignition switch was acting up so I connected a remote start switch to the starter. The pump would activate but nothing from the never used before starter.
The ignition switch also activated the pump but nothing from the starter.
So, junk starter, possible intermittent contact at the relay from a bad connection, jury still out on the ignition switch.
Got a starter from a friend and got it back in with the help of a friend with tiny hands, appropriately masked of course.
Will attempt to start again tomorrow but first I will find a young hippie chick to burn some sage, dance and sing. (IMG:style_emoticons/default/wacko.gif)
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rbzymek
post Aug 23 2020, 08:11 AM
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QUOTE(djway @ Aug 22 2020, 11:46 PM) *

I believe I had/have multiple issues.
I replaced the yellow wire fitting onto the relay as it seemed weak, fragile.
After that I was concerned that the ignition switch was acting up so I connected a remote start switch to the starter. The pump would activate but nothing from the never used before starter.
The ignition switch also activated the pump but nothing from the starter.
So, junk starter, possible intermittent contact at the relay from a bad connection, jury still out on the ignition switch.
Got a starter from a friend and got it back in with the help of a friend with tiny hands, appropriately masked of course.
Will attempt to start again tomorrow but first I will find a young hippie chick to burn some sage, dance and sing. (IMG:style_emoticons/default/wacko.gif)


Here is another test you can do. Remove the air cleaner. Place the key in RUN and push on the air vane. This should cause the pump to run. On a normal start the fuel pump is powered during crank. When the engine fires the air flow moves the vane, closes a switch and keeps the pump running. You may already know this but I could not tell from your trials.
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