2ohoh2

A few M20 electrical questions

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So I am almost done with an M20 swap and have a few loose ends to wrap up which I was hoping people here could give me a little clarification with. 

 

First up is the wiring for the E30 in tank fuel pump and the external fuel pump. In 6 into 2 they say that you ground the external fuel pump and run a line directly to the harness and connect it to the violet/red wire in the C101 connector.  I did this and it did not run or get any voltage when I turned the car on. Am I misunderstanding and should I just run a line to some other positive that turns on when the car is on? 

     The other question on fuel pumps is how do I connect the E30 in tank fuel pump, seeing as it has different connectors than the original 2002 pump? I didn't see anything about this in 6 into 2 and I haven't found any posts about it in my searches. photo below shows the E30 pump connectors and wires (red and blue circles) and the 2002 wires circled in orange.2018-03-22_11_44_36.thumb.jpg.97a27a8f2d61224f0fe7c1e87a7a710e.jpg

 

Next thing is these connectors between the ignition coil and oxygen sensor on the E30 harness. What do they connect to, or are they not necessary in the 2002?

2018-03-22_11_42_44.thumb.jpg.ddf6f587539aab58238e0a75547cf9c0.jpg

 

Next. What is this twist lock connector for? I assume that it connects to another part of the E30 harness that is not part of the installation into the 2002, but I want to make sure I'm not missing anything. 

20180320_173518.thumb.jpg.bb632f0a46b46003bd07e68164e2002d.jpg

 

I also am missing a couple lines for the vacuum system and wanted to clarify what's going on with that. 

On the back of the intake there are two nipples, one has a line that is connected to the fuel pressure regulator, and the other side didn't have anything connected to it when I get the motor. What am I supposed to connect that to? I have done multiple searches and mostly found versions of this part that only has the nipple on the right side to the fuel pressure regulator. Anybody know what's going on?

2018-03-22_11_46_50.thumb.jpg.0d133e145e677b85ba636f0752355373.jpg

 

and the last thing for now. The motor came with a few lines chopped up for some reason, and I was wondering if anyone knows the part number for the hose that connects to this outlet on the intake boot?

2018-03-22_11_48_06.thumb.jpg.90af1df9cd8c2114bcc898c11ab3bd75.jpg

 

Thank you so much for any input on this, as always it's much appreciated!

2018-03-22_11.44.36.jpg

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I can help with some but not all of the questions.

Motonronic doesn't close the fuel pump relay until there is an indication of cranking rpm.  So the pump isn't gonna run with just the key on.

At the tank the wires circled in orange are fuel gauge level.  Brown (earth) is ground, other goes to the dash gauge.  The intank pump is has three because it has a low level contact.  The brown there is also the ground. Brown/green goes to the dash gauge wire.

If the twist lock connector has 15 pins, it is the diagnostic connector and connects to nothing and should have a cap on it to keep it clean.

If you study the E30 wiring diagrams, you should be able to trace out the unknown wires.

http://wedophones.com/Manuals/BMW/1984 BMW 318i - 325e Electrical Troubleshooting Manual.pdf

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The nipple on the boot goes to the brake booster booster on some e30's- you can buy one without, or just plug it.

 

That second nipple isn't on any of the M20's I have.  I vote cap it.

 

The 2 ring connectors look familiar- pull the jacket back a little, and check wire color.

The ETM is invaluable for things like this.  You go looking for color, and match gauge.

 

t

 

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Thanks for the feedback! I will definitely jump into the  ETM to try to work out some of my confusion .

 

Jimk- For the intank pump, does that mean that the brown/purple wire should get connected to purple/red wire in the C101 connector (same connection as the external fuel pump)? If not what should connect it to power? 

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1 hour ago, 2ohoh2 said:

For the intank pump, does that mean that the brown/purple wire should get connected to purple/red wire in the C101 connector (same connection as the external fuel pump)? If not what should connect it to power? 

I was referring to the level gauge.  The original wiring was single feed to both pumps and was green/violet.  Green is usually 12V and the strip color varies with the service.  The intank pump for the E30s with a two pump system comes from the power feed.  Wiring is shown on 1360-1 sheet of the wiring diagrams.  You are using a fuse in that feed?  It's supposed to be after C101 15 amp. (BTW, you already have the pumps, but later cars use a single high pressure in-tank pump.  Thus eliminating one pump.  So if one ever burns out, consider a pump from a 325is or ix)

Edited by jimk

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I was referring to the level gauge.  The original wiring was single feed to both pumps and was green/violet.  Green is usually 12V and the strip color varies with the service.  The intank pump for the E30s with a two pump system comes from the power feed.  Wiring is shown on 1360-1 sheet of the wiring diagrams.  You are using a fuse in that feed?  It's supposed to be after C101 15 amp. (BTW, you already have the pumps, but later cars use a single high pressure in-tank pump.  Thus eliminating one pump.  So if one ever burns out, consider a pump from a 325is or ix)
Ok, gottcha, and yes I have a 15 amp fuse in line to the fuel pump.

Wish I knew that about the later model 325is fuel pump, would have been easier and cheaper. Oh well, next time.

Sent from my SM-G920V using Tapatalk

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Two connectors near O2 sensor are for ground. I grounded them to one of the strut bolts. The twist connector is the diagnostic port - mine has a cap and I just mounted it in the stock location. For the intake boot, get a new one without that extra port - those boots get cracked over time and can cause air leaks and idle problems. The port on the intake manifold - plug as TobyB says or swap out that cap for one with only one port. 

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On 3/24/2018 at 7:43 AM, jprocket said:

Two connectors near O2 sensor are for ground. I grounded them to one of the strut bolts. The twist connector is the diagnostic port - mine has a cap and I just mounted it in the stock location. For the intake boot, get a new one without that extra port - those boots get cracked over time and can cause air leaks and idle problems. The port on the intake manifold - plug as TobyB says or swap out that cap for one with only one port. 

Awesome! thanks for the confirmation, I really appreciate the help. Almost there!

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