It starts, but.....

[Mr. Horsepower]

Doing a S50B32 swap into my E30M3.

Got the engine running yesterday but there are some strange faults with the electric. Engine is 98 and car is 87.

When I set the ignition to pos. 2 the starter starts to go and the engine will start. When engine starts the start motor does not stop running. So I have to take the wires apart for it to stop (just to see if she runs well). Starter shall not start before hitting pos. 3 with the ignition (key) and it is also supposed to stop when the engine starts.

Another problem is that the fuel pumps has changed polarity, so it blows bubbles into the tank rather than pushing fuel forward Yesterday I unplugged the in tank pump and changed plus and minus on the in line pump just to get her started. But it cant be that way.
I have not done anything with the fuel pumps except changing the in line pump to a 044 pump.

Also have the phenomenon that the sun roof will only work when the passenger door is open. Have heard that this is a common problem when you don't have an engine in the E30. This also includes the heater fan, who don't work at all.

So, any one got ideas?
I have the colors of the wires and how I did wire if it is needed.
Engine is out of a English march 98 E36M3 3.2l Evo.
Car is December 86 non catalyst 200hp version.

Cheers
Bjorn

[7pilot]

It sounds like a miswired the circuit of the unloader relay at the starter.
Black/yellow wire T18 at c101 connector goes to T50 at starter.
Black/green wire T15 at c101 to starter T30h.
if it is already connected this way, then you may have a problem with the starter.

As far as the fuel pumps are concerned, i suspect that it is not the polarity of the electrics, it is that your return line has been connected to the supply side of the fuel rail and vise versa.

m

[Mr. Horsepower]

Even if i know which one, I always check who of the two lines are turn and return. And when I was doing that, both pumps did run but no fuel from ether of the lines. I then removed the back seat to unplug the in tank pump to check that it was running. And when I did that the in line pump went for i'ts 3-4sek, and I heard bubbling in the tank. Which means that it was going in revers, blowing air into the tank instead of sucking fuel from it.

I then simply just switched plus and minus on the in line pump (still the tank pump unplugged) and tried again. Then I got fuel from the line in the engine bay, then I connected the fuel lines to the engine. I have been dealing with fuel systems a lot earlier and I also taped the hoses when removing the engine from the E36 in case I was going to be unsure when getting the engine into the E30M3.

So, maybe T50 and T30h is switched and that is the result of the starter issue. I was thinking of changing them on the starter in case I had get them wrong on the starter. But after checking there starter and cables it is (almost) impossible to wire that wrong. Since it is two size on the cable shoes and the pin bolts on the starter.

I have tried to wire c101 nr 18 with x20 nr 18 and c101 nr 6 with x20 nr 18, but same result. Also measured c101 nr 18 and c101 nr 6, they both have 12v when ignition is on position two.

Bjorn

[FredK]

Mr. Horsepower has an early E30 M3, which does not have a pin 15 in the C101. The problem is, he is getting power in START and RUN at C101 pin 18. This makes the starter turn in the RUN position.

In an early E30 M3 as well as early E30s, when you turn the key to start, it closes the start relay. With the start relay closed, +12V powers chassis splice S233, which is connected to T85 on both K5/K7 (unloader relays), as well as powering the instrument cluster and most importantly, T50 on the starter.

Jason89i had this exact problem, as he had an early 87 production M3. What he did was to remove the power going to the unloader relays at S233, as well as to the instrument cluster, such that the ignition switch powered ONLY the EWS box then starter T50.

I believe he ran the BK/GN wire from the E36 harness that normally powers pin 15 on the C101 to the wires that were disconnected at S233.

S233, from what Jason said, is on the driver's side door sill, necessitating removal of the seat and pulling up the edge of the carpet to access it. ETM page 8000-2 verifies this.

Original thread: http://www.r3vlimited.com/board/showthread.php?t=85278

[Mr. Horsepower]

WOW dude! That was many T's and K's and what ever things I don't know what is :S
Ummmm, I will try to take notes and see what I can find out.

What you are saying is to run a wire from E36 harness down to a relay (S233) which is located on the door sill on driver's side?

Can this maybe affect the change in polarity for the fuel pumps as well?

[Mr. Horsepower]

Start motor problem solved.

Simply took the Black/Yellow cable (thick) that goes via one of the small relays in the engine loom and cut it off and put it together with nr 18 in the c101.

That leaves the fuel pump and sun roof mystery left!

[FredK]

S233 is a splice. A splice is where a whole bunch of wires just connect to each other at a single point. It's probably a big crimp. Just look for where five BK/YL wires join each other at a single point.

The arrangement SHOULD be the following: (2) 2.5mm wires, and (3) .5mm wires.

The three .5mm wires need to be removed from the splice. The two 2.5mm wires need to remain connected. After you remove the three .5mm wires from the splice, ensure there is continuity between the splice and the starter, and the splice and the ignition switch.

Now, you have three .5mm wires remaining. These wires should be connected to the BK/GN that is on the E36 wiring harness.

As for the fuel pump, I am not sure what the issue is.

[FredK]

Start motor problem solved.

Simply took the Black/Yellow cable (thick) that goes via one of the small relays in the engine loom and cut it off and put it together with nr 18 in the c101.

The electrical system is still not getting unloaded, and you'll have to do that via the BK/GN wire from the E36 loom.

[Mr. Horsepower]

It is the BK/GN cable I have connected. It starts just like a normal car now you see. If the system gets unloaded or not I don't know. I talked to a E30/S50B32 guru and they have done it that way on a couple of cars with no issues.

Fuel pump problem solved!! OMG!! There has been put on a small cable shoe on the positive and a big cable shoe on the negative by the in line pump. I checked the cables and the positive was Green/Violet!

But, I don't have pin 15 in my E30M3 c101 on the car side! My donor c101 got it but not the car. How do I then solve the heater fan/sunroof problem?

[FredK]

Hm. Normally, the electrical system is unloaded through Pin 18 on early cars.

The rewiring procedure I outlined will allow you to both unload the electrical system and have normal starter functionality.

[Mr. Horsepower]

I connected the cable to pin 18 in the c101, and removed the little black relay that is located together with the other relays. Very simple indeed.

So, that problem out of the way. What about the sunroof and heater fan?

[FredK]

So you connected BK/GN on the E36 harness to pin 18 on the C101, and removed a black relay from the E36 wiring harness?

[Mr. Horsepower]

That is correct.
The sun roof problem also solved it self.

[Jason89i]

Mr. Horsepower has an early E30 M3, which does not have a pin 15 in the C101. The problem is, he is getting power in START and RUN at C101 pin 18. This makes the starter turn in the RUN position.

In an early E30 M3 as well as early E30s, when you turn the key to start, it closes the start relay. With the start relay closed, +12V powers chassis splice S233, which is connected to T85 on both K5/K7 (unloader relays), as well as powering the instrument cluster and most importantly, T50 on the starter.

Jason89i had this exact problem, as he had an early 87 production M3. What he did was to remove the power going to the unloader relays at S233, as well as to the instrument cluster, such that the ignition switch powered ONLY the EWS box then starter T50.

I believe he ran the BK/GN wire from the E36 harness that normally powers pin 15 on the C101 to the wires that were disconnected at S233.

S233, from what Jason said, is on the driver's side door sill, necessitating removal of the seat and pulling up the edge of the carpet to access it. ETM page 8000-2 verifies this.

Original thread: http://www.r3vlimited.com/board/showthread.php?t=85278

yep. what fred said.

just curious. what is the production date of your car? cheers, jason

[Mr. Horsepower]

Don't know the exact date, but it is December 1986 for the E30M3 and March 1998 for the E36M3 donor car.