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krisby
07-13-2004, 12:28 AM
I just got me a 1990 525 a couple of weeks ago, it was pretty good but I did notice that when moving away from junctions etc the engine would bog down, sort of stutter then it would be alright. Anyway after a week the fuel pump failed, so I was expecting a new one to eradicate the problem, alas no. I haven't been to see my mechanic again yet as I was hoping to be able to sound like I know what I am talking about, you know, so he doesn't string me along and I end up with a huge bill.

Does anyone know what could be causing this? If I slowly (and I mean slowly) press the accelerator it is ok, it is with a little zest that it stutters, nearly to the point of stalling.

Any feedback would be appreciated. I have read the maintenance stuff on the E34 site and it would suggest the fuel pump is dodgy, but as it is brand new I am ruling that out, unless the brand new unit is faulty too.

Thanks
winfred
07-13-2004, 12:48 AM
bad fuel pressure regulator?! has the pressure been checked? and was the old pump still running when it was changed or did it lock up? correct pressure for that car with the vacuum tube off the regulator is around 43 psi and about 5 less with the tube on at idle
Unregistered
07-13-2004, 04:02 AM
the old one actually failed, stranded me too, god bless the AA. Maybe I will suggest the fuel pressure to him then.

Thanks.
krisby
07-14-2004, 05:18 PM
the old one actually failed, stranded me too, god bless the AA. Maybe I will suggest the fuel pressure to him then.

Thanks.

peculiar, when my mechanic drove it the problem did not occur, so we popped the hood, when blipping the throttle from the engine it then stuttered. He reckons the TPS is at fault as it looks like never have been adjusted, so next time I have the car serviced he will take that off too and set it up right.
George M
07-14-2004, 05:22 PM
one...change the fuel filter if you don't know its history and two...as Winfred suggested...check the in-line fuel pressure to remove either the fuel pump or regulator from the equation.
HTH,
George
632 Regal
07-14-2004, 06:50 PM
yes, sounds like the filter(s) could be clogged, mine were quite dirty when I changed them. Where is the pressure regulator anyways? Just for my own knowledge.
winfred
07-14-2004, 09:09 PM
sometimes they hide it on the bottom of the car right under your ass under a cover by the frame on later bimmers, or it's on the fuel rail


yes, sounds like the filter(s) could be clogged, mine were quite dirty when I changed them. Where is the pressure regulator anyways? Just for my own knowledge.
FIRO...AZM!!!
07-15-2004, 05:11 AM
Do you have pictures for this?
so it will help to check & replace if need


Thx
winfred
07-15-2004, 08:54 AM
heres one of the fuel rail mounted regulators on a early v8, it's the silver round thing to the right of the intake, the line closest to the regulator is the return line
http://members.cox.net/wdixon27/v8%20pcv
after 95 they started to put them on the bottom of the car, i don't have a picture of that


Do you have pictures for this?
so it will help to check & replace if need


Thx
krisby
07-15-2004, 06:56 PM
it shouldn't be my fuel filter cos I had my fuel pump two weeks ago, and the filter was replaced at the same time (has to be for the warranty of the fuel pump).

He still reckons the TPS so will have that looked at next time it is serviced. Though when I sell my house (hopefully shortly) I will get the EAT and that might help too.
632 Regal
07-15-2004, 07:02 PM
it shouldn't be my fuel filter cos I had my fuel pump two weeks ago, and the filter was replaced at the same time (has to be for the warranty of the fuel pump).

He still reckons the TPS so will have that looked at next time it is serviced. Though when I sell my house (hopefully shortly) I will get the EAT and that might help too.