Subject: This is the Solution from ( Shogun ) Author: bmw740jor : member since March, 2008 : 221 posts Posted on: 2009-11-07 12:02:43

Check valve:
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Written by Bill R. today:
Well the poor old 535 and her new fuel pump that i had gotten off of ebay weren't quite right....
Since i installed it ,the tank,filter and injectors, I was having the usual hot start problem with 3 trys to start it when hot soaked...

I checked the fuel pump pressure and it was good but instantly went to zero,when shut off, I thought to myself it could be the fuel pump check valve, or the fuel pressure regulator letting fuel drain past, or a number of leaking injectors. So i deadheaded the pump by pinching off the return line from the regulator and briefly cranked the engine, gauge shot up above 70 and then when i stopped cranking instantly went to zero
That pretty much confirmed it. So i installed the bmw retrofit check valve kit 16 14 9 068 988..... pretty cheap from Patrick at bma, less than 10 bucks. Nice kit ,comes with checkvalve, fuel line, hose insulator, hose crimp clamps and plastic nut covers to get rid of sharp edges on the pump cover.

After running it for a good while getting it good and hot, shut engine down and waited 45 minutes with the pressure gauge hooked up... Pressure guage only dropped to here
16149068988
CHECK VALVE KIT $7.00
http://www.bmaparts.com/
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Vehicle information
Series: 7' E32
Body: Saloon
Model: 730iA
Engine: M60B30
Cylinders : V8
HP : 218
Region: ECE
Version: Left Hand Drive
---K---&--N-- Filter
Transmission: Automatic 5-Speed
Manufact. date : 07/1992

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