Hi all,

I have a 1988 740 turbo, b230ft, stock. Car has been driving great and then I stop at the store, start the car and within a few seconds it dies (pretty sure fuel related). It wouldn't start back up for a while so I went swapped a known good fuel pump relay and the problem continued.

Got the car towed home and started it so I pulled it into my parking spot. Pulled the vacuum line for the fpr and it reeked of gasoline. So I am planning to replace that tommorow.

Another thing is my in line fuel pump is quite noisy. Could a faulty fpr cause this noise or am I looking at a new fuel pump as well? Also I can hear the intake pump whirring.

Thank you for any input.

If the FPR is in really bad shape I suppose it could cause a strain on the main pump??

Worst case scenario here is that your main pump is dying. How many miles on your car? Often the main pumps can outlast the car. They are usually good for at least 250k. Before condemning the main pump I'd diagnosis other areas of the fuel system and look for a potential cause of the noise in your main pump.

Are you sure that your in-tank pump is good? A dying in-tank pump can strain a main pump and make it noisy. Before it died did it run poorly with less than a quarter of a tank? The in-tank pump may be running but it could have another issue like the little black rubber hose is shot or the mesh sock has come off.

You might also consider changing the fuel filter too if it hasn't been changed in awhile.

If you dive into diagnosing the main pump also check the condition of the main fuel pump check valve especially if you end up replacing the filter since you'll be there anyway.

The following link from the 700/900 FAQ might help you diagnosis your problem.

https://www.brickboard.com/FAQ/700-900/FuelSystem.htm#Fuel_Pump_Noise

Hi and thank you for the reply I very much appreciate the help. Car has around 240,000 miles.

So I swapped in a new fpr with great results. Car stays running and the in line fuel pump is quite as a mouse. Also seems to have fixed a problem I had where shifting into neutral the car would try to stall. I.e. Rpm would drop to around 200 and then shoot up to 1200 before stabilizing.

I'm doing other work to the car so I haven't taken it for a long drive yet but I feel fairly confident the issue is resolved.

I'm going to get an oem fpr eventually but has anyone had experience with gp Sorensen?

Thanks again