| NSR21L |
Posted
Thursday, Nov 16th 11:09am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 7
Sydney NSW
BMW E21 323i |
Hi everyone, im doing a K to L jet conversion, following the threads from madhatter and aussie_323 as a guide i have so far swapped manifolds from the e21 323 manifold to the 325e removed all components that had to do with
k-jet basically my 323 is ready to run but i have a problem with the engine loom, i have sourced one from a e28 520i and so far i've soldered on the alternator, oil pressure, ignition & temp wires. does anyone by any chance have a diagram that i can use to complete my conversion as i am aware that the wires that connect to the old k-jet pump relay are different to the L-jet as well as other connections that i don't know of.
will greatly appreciate your help,
regards
Simon |
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| aussie323i |
Posted
Friday, Nov 17th 10:02am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 538
australia
1979 323i |
OK... as I have had many requests about this conversion, I have pulled my plug apart so I can refresh my memory as to how this all hooks up, and I have taken some pics. Before I get flamed for the state of my engine bay/ wiring etc. etc. remember that my car is my daily driver (so don't expect under the bonnet to be a show piece- it's certainly not!) and also that I have peeled off the wrapping from my wiring loom to check the wire colours so it looks worse than it really is.
Also bear in mind that since doing this conversion I have had more than 2 years trouble free motoring.
The pinout is fairly straight forward for the L-Jet system, and there are only 8 wires to connect to get your car up and running- I have no idea whether my diagnostic plug works on the L-Jet... I have not hooked up several of the wires for it, and I certainly have no access to any BMW special tools, so I don't care- if you want your diagnostic plug to be 100% working, then you're on your own. 
Basically to do the wiring conversion, you need the entire e28/ e30 loom including the ignition system and the fuel pump relay. KEEP THE WHOLE LOOM INTACT. The only thing you need to do is cut off the e28/ e30 engine loom plug, and solder the wires up to an e21 engine loom plug and the loom will then plug straight into the fuse box.
The L-Jet fuel pump relay fits on the side of the e21 fuse box like it was supposed to be there (and replaces the e21 fuel pump and diode relays).
The e21 engine plug has 15 places for pins... they are not all used. The pinout is as follows:
Pin 1 (Oil Pressure light, brown/green)connect to brown green on the e30 loom (pin 16).
*please note that the haynes manual wiring diagram lists the oil pressure signal as being pin 1... on my car (series 1 e21) it is actually pin 11... check this on your loom- the wire colours should be correct.
Pin 3 (Fuel Pump, Green/ Black) connect to green/ violet on the e30 loom (pin 7).
Pin 5 (Alternator Light, Blue) connect to blue on the e30 loom (pin1).
Pin 6 (power) connect directly to the green wire coming from the L-Jet ECU- you'll need a new length of wire for this (see pic below).
Pin 8 (ignition, green) connect to the green wire in the e30 loom (pin10)
Pin 10 (starter, Black- two wires) connect to Black/ Yellow on the e30 loom (pin8).
Pin 13 (Temp Guage, Brown/White) connect to Brown/ Violet on the e30 loom (pin 4)
Pin 15 (Tacho Signal) connect directly to the Black Wire from the L-Jet ECU... once again you'll need a new length of wire for this one.
Once these are all soldered up and insulated,you should be able to simply plug the loom into the fuse box, fit the fuel pump relay to the side and you're away.
The wiring loom is tight through the standard place in the e21 firewall, but it does fit and the computer mounts easily in the glove box.
You can see there are actually 3 loose wires running to the computer in the pic (outside of the main loom). The green and black ones have been covered in the pin out. The brown/yellow wire is for the service indicator in the e28/e30, and is not needed in the e21. Also you can cut off any other wires you don't need in the e30 loom and insulate them.
On the distributor, you will need to fit an e30 socket to plug in the e30 ignition module. This is straight forward, and you just pop out the e21 one, and plug in the e30 socket. Then the wiring just plugs straight in.
Other than this, just install the e30 fuel pump by hooking it up to the standard wires under the car. I have removed the e21 fuel accumulator and have had no problems. The fuel rail in the e30 has a check valve, and it holds the pressure in the system, so the fuel accumulator is no longer required.
I hope this guide helps some people out... please note my car is a series 1 (November 1978 build) there may be small differences with the series 2 cars.
Hatter, you may be able to help out here as the car you did was a later one from memory.
Usual disclamers apply... if you follow this guide and screw up the onus is on you... you know the deal.
Cheers
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| realcrouton |
Posted
Friday, Nov 17th 9:55pm [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 72
Washington, USA
1977 320i, 1981 323i, 1991 325ic, 2000 328i |
Aussie, thanks a TON! I'm going to be doing this exact swap one of these days and was very nervous about fitting that L-jet wire loom.
This is going to help me out so much!
-Dave |
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| NSR21L |
Posted
Saturday, Nov 18th 12:14am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 8
Sydney NSW
BMW E21 323i |
 Thanks so much for your help Luke, im going to straight away today get it the wiring done and get back to you how it turns out, ill post some pics of how the engine bay turned out as well as the car up soon as well.
thanks again.
Simon. |
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| aussie323i |
Posted
Saturday, Nov 18th 2:52am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 539
australia
1979 323i |
No problem guys... I hope it all works out for you!
Dave... the pinout may be slightly different for you guys in the states because you had the LE-Jet with lambda sensor- we did not have that system down here... I think it will be close though.
As you can see from above, the wiring colours aren't all that different between the looms.
Good Luck |
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| NSR21L |
Posted
Friday, Nov 24th 8:25am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 9
Sydney NSW
BMW E21 323i |
I have wired up the loom, did all last checks and tried starting it but i had no spark, did a continunity test and found i had a postive wire that goes to the coil was with the black on the negative. that was solved i know cause i was shocked lol, tried starting again just when i thought it was going to start up it dies then doesnt want to start i try like 5 mins later and same thing ,
when you have ignition key on accessories and push the air flow meter flap should the pump run on?
i just dont know what the problem mite be im pretty sure it must be small.
hopefully someone can help me
Simon |
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| aussie323i |
Posted
Thursday, Nov 30th 1:23am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 544
australia
1979 323i |
Hi Simon
When I first fired up my L-Jet I had a similar non starting problem, and it was the injectors (I grabbed 2 sets from the wreckers when I bought the system. I put the others in and it fired up straight away.
Check out the L-Jet trouble shooting in the e28 manual- this can probably help you to work out the problem and give you an idea about how to test things. Just double check all your earths and vacuum hoses too. For example, I ran an extra earth from the top of the head to the firewall the same as the e30/ e28 has when I converted.
I'm sure it will tell you in the manual what pins to jump in the fuel pump relay to get your pump to run all the time for testing. On the L-Jet you should hear the fuel pump fire up when you turn on the ignition (dash lights on) and then switch off again when the computer sees no airflow. (This also helps pump a bit of fuel up into the fuel rail).
Good Luck |
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| NSR21L |
Posted
Sunday, Dec 3rd 10:20am [Edit] [Quote] [IMS] [View car] |
Member
Post nr. 10
Sydney NSW
BMW E21 323i |
Ill go to the wreckers this weekend and find out.
i've done that earth strap upgrade reading from other posts will let you know how it goes.
thanks |
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