Fuel Pump Flow Rate

[Scutt]

The Bentley manual shows the minimum flow rate for the inline pump at .875 liters per 30 seconds or roughly 105 liters per hour. I found this online:
http://www.onlyfuelpumps.com/oem-rep...p-hfp-603.html
This pump only shows a flow rate of 100 liters per hour (i noticed that after i installed it).


I bought it, a new in tank pump (from oreilly), fuel filter, plugs, wires, air filter and ran the high strength fuel injector cleaner through the rail. Yet i am still having sputtering at high demand (wot in third gear at 3000+ rpms and top of second).

I am starting to wonder if the flow rate is what is causing me issues. Has anyone tried this pump or does anyone have any ideas? Just a heads up, I bought the car this summer after it was garaged for five years not being driven.

I opened up the tank and checked it, found no signs of rust or other particles. Plus i think there is an aftermarket inline fuel filter after the stock fuel filter. I might remove that tomorrow night and see what happens. Anyone know if there is a second filter or fuel pressure regulator immediately after the fuel filter? This is my first E30 but that doesn't look factory. Ill try to post a picture tomorrow.

Thanks.

[jlevie]

I don't think the very slight difference in flow rate is is the issue.

There should only be one fuel filter, but there could be the OE vibration damper after the filter. That might be what you perceive as a second filter.

You need to check the fuel rail pressure to see if the pump is working correctly and to see if the fuel pressure regulator is working correctly.

[Scutt]

Checking the fuel pressure in the rail was my next step so, I guess I'll have to give it a shot. Thanks for the advice Jim.

[SpecM]

I hate to say this (because I work at O'Reilly) but Airtex pumps are kinda "meh" pumps

not saying that that is your problem, but it wouldn't floor me if you had a bum pump

[Scutt]

well I just decided to replace the fuel pressure regulator. It made no difference. The problem is actually gradually getting worse. I pulled the vibration damper and replaced it with straight hose. When I restarted the car, the oil pressure light stayed on a little longer than normal. I checked my dipstick, oil level is fine but ive got spots of white foamy oil on the dipstick..... not good.

Coincidence, i also have a coolant leak ive been chasing for the past month or two. It did pass a pressure test.

As far as i can tell all signs point to head gasket. Anyone else thinking the same?

Well I needed to do the timing belt and tensioner pulley anyways. Might as well and throw in the water pump, valve adjustment and all the rest of the belts. Any advice?

[jlevie]

What is the rail fuel pressure?