- Parent Category: BMW Tech Talk
- Category: BMW 3 Series
- Published on Tuesday, 25 May 2004 00:00
- Written by Jeff Seabrook
- Hits: 3343
Replacing the Low Pressure Fuel Pump on the e30 3 Series.
As I hear, this applies to the 1990 and 1991 BMW e30 3 Series, because the Low Pressure Fuel Pump is different than that of the 1984 to 1989 e30 3 Series.
Philips Head Screwdriver
13mm, 8mm, 5mm sockets, socket wrench.
Time: 30 minutes.
First thing to do is disconnect the Positive terminal of your battery (tip from Peter 89 325iX ), this will prevent any dropped fuses, and for your safety.
Start by removing the "seat" part of the rear back seat. Pull up on each side until it's removed, easy. Pull up on the carpet on both sides to get it over the hooks, and then remove the soft padding underneath the carpet that pulls back the opposite direction:
Now you will use your philips head screwdriver to remove the 4 screws on the cover plate, you will then expose the Low Pressure In Tank Fuel Pump.
You'll want to remove both wiring harnesses at this point, and push them back out of the way.
Next you'll use the 5mm socket to remove the hose clamps that lead directly to the pump. Wrap a rag underneath this hose, and around the fuel pump to catch the fuel that will come back down that hose ( low pressure ). Pull the clamps to the left onto the "J" section of pipe coming out of the fuel pump (to prevent them from falling into the tank later on). Now you can unlock ( not remove, yet ) the fuel pump by turning it COUNTER CLOCKWISE about 1/2 inch until it unlocks.
Once it's unlocked, pull up a little on the fuel pump for enough room to put the hose into the tank to catch the rest of the fuel.
Now you'll get the 8mm socket to remove the 4 bolts holding the sender in, located on top of the fuel pump. Remove all 4 bolts including the washers underneath them.
Pull the Sender straight up and let some fuel come out, and then pull it straight up and out, and use the rag to catch the fuel that will be emptying out if any. Place that outside the car on a rag, or anything clean. Now you can remove the fuel pump by pulling straight up, and make sure to get the rubber ring from the contact plate (your new pump should come with a new rubber ring).
Quick Reference to put the new fuel pump in:
Get the hose clamps from the old Fuel Pump, and put them on the new fuel pump "J" section of the pump. Drop in the new fuel pump, make sure the new rubber ring is between where the pump will go, and where the tank meets it, don't turn it clockwise to lock it in yet. Drop in the Sender, and replace the 4 washers and bolts. Now you can lock in the fuel pump by turning it CLOCKWISE.
Next thing to do is re-connect the hose going to the fuel pump, and using your 5mm socket to tighten the hose clamps back on the original position.
Now you can re-connect the harness wires, then re-connect your battery.
Once you are sure everything is back in place and looking good, go ahead and turn the key to the "ON" position, for about 15 seconds to let the fuel pump cycle the fuel up into the hose.
Now you can start the car, it will hessitate while it gets fuel, and then let it run for about 2 minutes.
If everything looks good, go ahead and replace the cover plate and the screws. Then the soft cover, then carpet, and then the seat.
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