is their a strainer for the gas? - BMW Forum

87325es · 10-27-2006, 09:44 PM

I removed the fuel pump on my 87'325es the one under the car. Is fuel supposed to out from the hose coming from the tank? because it is'nt. What is that round filter looking thing which is attached to the fuel pump with a small piece of hose? Is that a strainer? How does the intake fuel pump work? The reason for all of these questions is I cant get any fuel in the lines going to the engine. Sitting for a few years.

Starmavin · 10-27-2006, 10:31 PM

There is an accumulator before the main pump (external pump), then there is a anti-pulse diaphragm after. That pump is main pump, the transfer pump (internal pump) is what feeds that. The transfer pump is in the tank (where the strainer is), you'll find it's access plate under the rear bench seat on the passenger side. If the car has been sitting up for a while there is a good chance that the tank is full of gunk.

You can buy a fuel pump for a 90 325I and do away with the large external pump. But I can't remember the part number off hand.

87325es · 10-27-2006, 10:46 PM

I changed the internal pump already. Today i took out the external pump and hooked it up to a battery and it works. But I cant determine if the internal pump is working or if im getting current there, the fuel level unit works it shows it on the cluster that it is a 1/4 full so the level thing is working.. When I took out the external pump the hose that connects it to the tank is not leaking down fuel. Is that the problem that not enough fuel is bening sent to it? When I removed it the two wires that are connected to the pump on its end I touched them together and saw no sparks does that mean there isn't any current? Is the strainer in the tank? Does that have anything to do with no fuel coming through that end of the hose which goes to the external pump?

Starmavin · 10-27-2006, 10:54 PM

Check your fuses first. Then check the fuel pump relay.

87325es · 10-27-2006, 10:57 PM

Which relay is for the fuel pump? Thanks for replying to my Threads

Starmavin · 10-28-2006, 11:01 AM

Your fuel pump relay is located just before the strut tower on the drivers side. (it's not in the fuse box) There you'll see 3 relays (they often have a black plastic cover on them) The one it the middle of the 3 is the fuel pump relay.

87325es · 10-28-2006, 11:33 AM

How do I check if the relay is working? And is the relay covered in a small rectangular box?

Starmavin · 10-29-2006, 12:48 AM

Before you go fingering it, use a test light and check for power at the transfer pump plug, don't for get that you won't have power there unless the engine is being cranked.

87325es · 10-29-2006, 11:05 PM

Ohhh so the only time current is being sent is while the engine is being turned over? Since I removed the ex-pump isn't there supposed to be fuel leaking down from the unattached hose?

Starmavin · 10-30-2006, 03:07 PM

Yes and there should be fuel comming out. Check for power at the transfer pump. Remember the oval tube held in with 4 nuts is not your fuel pump, that is your fuel level sending unit. Make sure that the plug is tight and clean.

87325es · 11-03-2006, 05:52 PM

Is it easy to replace fuel tank on an 87' 325es? What are the steps to removing it? What all needs to be taken out? And what are all those hoses that go to the intank fuel pump? Which goes to what?

87325es · 11-14-2006, 10:52 AM

I am ordering a fuel pump relay how many prongs are on the fuel pump relay for a 1987 325es? they asked me if it has 4 or 7

Starmavin · 11-14-2006, 06:25 PM

Yours is a 4 prong, the same as any regular light relay, your main relay is a special 5 prong.

But first, are you getting power to the main pump?

Changing the tank is rather involved, you have to remove the drop exhaust , the heat shields, and drive shaft. About 3-4 hours on the ground depending on your tools and how adept you are.