The Steinbauer BMWs:
Rick and Rainer's BMW
633 CSi (Igor)
3 Feb 18: Still drives funny and keeps dieing. Played around and I guess now that the in tank fuel pump
is not connected and the inline pump is failing. Very noisy and when the intank pump is connected the
fuse burns out. The fuse is the right rating (16 amp) but keeps burning out. I have a spare pump from
Victim which I will install next weekend.
That was not the case either. Decided to go with the in-tank pump option but that so far is nothing but
trouble. Igor seems to really like it in the garage. He just died in there. I thought that my AFM (Part
#13621359641 -Bosch #0280203002) died since it looked like it no longer sends a signal to the double
relay (1979 M90 L Jet engine) and hence the car does not run anymore.
I do have continuity from the battery to the fuse box and again to the double relay and continued from the
double relay to the fuel pump. If I jump the two connections by the double relay I get a humming from the
fuel pump. I understand that the AFM is supposed to send a signal to the double relay which kicks on the
power that gets the engine going when the flap opens in the AFM and it's also supposed to click. Well, it
does click but still no power to the pump. The thought that the DME is busted, since it smelled burned
had crossed my mind but according to the diagram the DME has no say in this.
Had the AFM open. Everything looked OK. With the ignition on I got power to port 39 and when I open the
flap power goes over to 36. So the micro switch seems to work. I checked continuity from both wires to the
double relay and we have continuity. I have an old double relay in and also connected the new relay and
still nothing. Lack of ground on 6 maybe? Is there any other item that would enable the power to the
So from the way it looks the AFM is good. I get 12V to the AFM and when the flap is opened 12V go out. I
measured at the connector by the relay. I can also hear the click at the relay. There is ground at #6 at
the AFM but only when the ignition is on. So from the way it looks the circuit is good there. Does the DME
provide input to the fuel pump power cicruit?
I ordered a DME, it arrived and I could not wait to plug it in. Plugged it in and measured for voltage at the
pump. YES!!!! I had what it takes! I put the thermostat housing back in (had to change the thermostat
since it was stuck in the open position due to the PO sticking a screw in there). Had some complications
since some of the screws broke due to old age and me beasting around (unrelated issue). Strange thing
is that for a while I have power at the pump regardless of ignition on or off and flap at AFM open or
closed. Did not last long though).
The car sat there for a while and when I tried it would not start anymore nor did I have current going to
the pump. If I apply 12V at the pump (bypassing everything going straight from the battery to the pump),
the car runs fine and as soon as I disconnect the power he dies.
I have to admit that I have not yet checked the red cable that leads from the ignition switch straight to the
24 April 2018: No, it was not the red cable but the Green/Yellow cable as I learned from the First Five
website. A very useful tool for 6er drivers as well.
So I found out that the yellow/green wire has a break somewhere. Did not take me long (after that
conclusion) to find out that the plug on the fuse box was melted at one point and the melted plastic
served as insulator.
22 Jun 18: Still battling with the fuel pumps. The Walbro in tank pump was not the ideal solution.
Ordered and started installing an in line pump. Did not get done that day since I just had to watch the
world cup game Germany vs Sweden!
30 June 18: Received the inline high pressure fuel pump (255 l/h)and installed it that day. Took out the
Walbro in tank high pressure pump and closed that tank off. No more pump in the tank now. Also tried to
make the vacuum lines right but got only part done. Car is not starting now but gets fuel and spark. You
can tell Igor wants to start but is not fully there. Have to check the fuel pressure to see if that pump
delivers enough pressure. Trying to do that 7 Jul 18.
7 Jul 18: Rented some test equipment from O'Reileys and it turned out that the equipment did not work.
. Finished up the speakers in Fritz and have a great sound now! Tom Schultz was kind enough to take
pictures of his vacuum setup so now I can connect everything on Igor the way it is supposed to be!
14 Jul 18: Even with Rick's tester, there was no pressure at all. Not even fuel came out. There was a
possibility that the pump was not connected right so I switched the polarity. Did not help at all. Checked
all the connections to make sure the flow is right and it was. While I had the front and the back
disconnected I thought it may not hurt to blow the line out and sure enough, there was a blockage and
putting reverse pressure on it cleared the line. Igor is running but I suspect the fuel pressure regulator to
be bad since it does not hold the pressure, Takes a while to crank but it will start up.
3 Aug 18: Switched out the thermostat housing and the lid since both of them were just a temporary fix,
At the same time I also looked for a fuel leak in the rear and the only thing I could find there was a leak on
top of the tank, the fuel level sender to be exact. Either the bolts are stripped or the nuts. Either way, it
no longer seals.