Hi all,

I have an '87 740 GLE wagon (250 000 KM) using the Bosch fuel injection system. Last week the short fuel line between the lower fuel pump and the fuel filter cracked. A visit to the wreckers produced a complete lower fuel pump assembly, I installed a new fuel filter with the wreckers fuel pump (I suspected my old pump was tired so I used the wreckers pump instead of my old one).

I seems that the check valve on the old fuel pump was bad as it now starts on a dime, but...(there had to be a but ;) ) though the machine generally runs excellent it intermittently has no power as though there is no fuel pressure. If i shut the car off and immediately restart it the car runs perfectly for a day or two then the symptom resurfaces. I presume that somehow this is related to the fuel pump as this symptom appeared for the first time immediately after changing the pump.

I'm not certain what to investigate: two ideas that have popped to mind:
1. the check valve on the wreckers pump
2. the fuel pressure regulator

I would appreciate the insight of one or many wiser than I whether either of these two parts might be the culprit or possibly another...

Thanks in advance.
Kevin