Help, Pump Failure?

[ruizl300]

So my 318i keeps dying on me while I drive. It will drive then shut down. I wait a while and it turns on again and drives for a short distance. I beleive it is a fuel pump problem. I checked the transfer pump and it doesnt turn on at all. It is getting 11.8v when I bypassed the fuel pump relay but I plug the connector in and I dont hear anything. So just want to make sure that it suppose to turn on with the same method as the in line pump to confirm .

[E30_Pare]

Sound like an alternator problem. U should get at least 12v. When running should be something like 14.4v.

[ruizl300]

I actually used a battery as well to try and get it going and at 12.6 volts still didnt get anything out of it. The car was not on, I just bypassed the fuel pump relay with the key on "On"

[E30_Pare]

I actually used a battery as well to try and get it going and at 12.6 volts still didnt get anything out of it. The car was not on, I just bypassed the fuel pump relay with the key on "On"

May well be the In tank pump. I've gone through a couple of those already with similar-ish issues. I've had the in line pump fail as well which caused a high idle problem. Only way to know is by replacing it. Good luck

[ruizl300]

Thanks, Im hoping that doesnt happen to me. I plan on keeping the car forever, so I really like all the advise and tips. Buying new parts is not pleasing but I like it to be reliable. Thanks.

[E30_Pare]

You may want to put a fresh fuel filter in first since that its cheaper & may also be part of the problem

[ruizl300]

Already tried that... no go

[rustybullet]

I have a very similar issue but my car starts up almost instantly like nothing.

I bet its the online fuel pump getting hot and shutting off, cools down and gets unstuck.

If the in tank pump goes the should still run but the outside pump will have to harder.

[bmwguy325is]

So I have a twin pump car too. The main pump only pumps when the engine runs or is in crank.
o test the tranfer pump I just pull off the large hose. Turn on key look for gas. If no gas bad pump. Kinda makes a mess but ya.

[ruizl300]

Yes my transfer pump was making buzzing noises before and wasnt pumping so i replaced it and then the car ran well for 10min and then on a different drive it shut down and didnt want to turn on anymore... the Fuel relay went out. I replaced it and now its running well.