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Fuel regulator replaced and fuel pressure is still too high--Please Help! 700 1989

Hi fellow brickers,

I have a 740 with the B230F engine, single overhead cam.

Help me if you can, I'm feeling down.
Original symptoms: Car takes about 10 key turns to start in 20 degree F weather for the first-start of the day. After that, it runs fine and starts fine for the rest of the day.

What I've done:
I put a homemade "T" with a gauge on the fuel rail inflow line and made the electrical jump at the proper fuel relay connectors; the pressure read 50psi. According to the Haines manual, the B240F engine should be about 36psi. Based on the high pressure reading, my guess was that the fuel regulator was probably bad.

I went to a local salvage yard and found an identical Bosch fuel regulator, replaced it and the pressure was the same--50psi. I put suction on the regulator vacuum port and the pressure decreased. When I pinch the outflow tube, the pressure rises sharply to about 90psi. When I release the pinch, the pressure decreases quickly to 50psi.

With the engine running, the pressure is about 44psi.

So what could be causing the high pressure reading?

Also, would this high pressure reading cause the car to have early morning cold-start problems?

I blew through the outflow tube and there was some resistance, much like you would expect when blowing liquid through a long tube, but I don't know if the resistance was too great and would have caused the higher pressure. Since this engine's fuel regulator is at the end of the fuel rail, I would imagine that extra resistance in the out-flow line could cause an increase pressure reading. Am I right in this line of thought?

Is it safe to blow out the outflow line with compressed air?

Other factors: The pressure gauge drops to zero after the engine is stopped. I'm guessing that this is because of my gauge connections, but I'm not sure

Thank you for any advice,

Bob






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New Fuel regulator replaced and fuel pressure is still too high--Please Help! [700][1989]
posted by  bobp  on Mon Dec 31 17:06 CST 2001 >


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