Fuel injection pipes

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Neil3478

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Does anyone have a diagram for the 2 U shaped fuel injection pipes that each have the three little connectors that go into the fuel injectors? I had to remove mine, as well as the injector pressure regulator, from the hoses and cannot remember how the whole lot was connected! I know the three bits that go into the injectors but somehow have been left with 4 bits of 8mm hose - 1 piece joins the 2 U shaped pipes, another piece joins the pressure regulator, another piece, I think, goes into another pipe but would like some clarification if anyone can assist, a picture would be ideal!
For a 1973 BMW 3.0 Csi, right hand drive, UK manual.

Many thanks if you can help!!
 
Neil: I am looking at the FI diagram on page 13-60/1 of service manual (I would send a picture but my scanner is down right now.) The pressure regulator is connected to each semi-circular fuel bar on the sides of the regulator. The connection on top of the regulator is the return fuel line (back to the tank.) The fuel supply line comes into the the front or rear fuel bar and the connection on the other fuel bar goes to the cold start valve. Don't know if there are any differences RHD vs. LHD...If you have a problem, let me know and I will haul my butt into my garage and look at the fuel setup on my '74. HTH.
 
Many thanks Bill, I think I understand it now! I dismantled everything because every time I started the engine from cold I got a fuel leak which dripped down the engine block. It appeared to be coming from the pressure regulator but was hard to be sure, but certainly from that area. Having taken the regulator off, it seems fine, no obvious holes or leaks. I am hoping that when I put the fuel bar, regulator and hoses back together the leak will have stopped. Only happened when the engine was cold, when warmed up the dripping fuel stopped. If it still happens then I can only assume that the leak comes from the cold start relay, not exactly sure where that is though. The fuel bar (line), hoses and regulator all look fine, so a bit baffled! Many thanks again! My next post will be how to sort out the indicator (turn signal) relay which is driving me mad. Have 8 assorted relays, none of which make the indicators work properly!
 

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Neil3478 said:
It appeared to be coming from the pressure regulator but was hard to be sure
Click to expand...

I had a similar problem. Fuel was leaking from the bolt/nut adjuster side, at the threads. The diaphragm-thing inside the pressure regulator failed/leaked. A warm engine would(?) evaporate the fuel which is why you might only see the leak at cold start-up. Getting a new pressure regulator solved it.
 
The cold start valve is located in the middle of the intake plenum ("log.") In addition to the fuel line, it has an electrical connection from the cold start relay which, on my car, is located under the brake booster support tube along with the FI main relay. BTW, the plenum on my car had a leak from a small crack in the weld. It would show up when the engine was cold but disappeared when hot. Drove me crazy trying to find it until I removed a couple of the "C" tubes and saw daylight inside the plenum. A little epoxy cured it. Good luck.
 
Beautiful car, BTW. It is amazing to see any Aston Martin over here...but a coupe in England is quite a sight given their rarity and their relative size compared to other cars over there. Beautiful!
 
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