'88 325 Fuel delivery problem,..

On Sun, 30 Dec 2007 10:24:59 -0600, "Bill" wrote:

>
>"cosmo" wrote in message
>
>On Sat, 29 Dec 2007 09:32:29 GMT, "Jack"
>wrote:
>
>>
>>>
>>> It seems the fuel pump is working after all. I pulled the cover and
>>> stuck the hose in a pop bottle. When I crank the engine fuel comes out
>>> a plenty. Still no start. I'm kind of stuck here at this point.
>>
>>I'm not sure what you mean by 'the cover'.
>>This sounds like you are checking the transfer pump ( the one that's in the
>>tank).
>
>That's what has me confused. According to Bentley the 1988 325 has no
>separate transfer pump; just a main pump inside the tank, which is
>accessed by removing the back seat. However, on my '88 the item under
>the oblong cover on the passenger side looks exactly like the picture
>of a transfer pump for '84 - '87 models- one fuel outlet, a white two
>wire connector (fuel gauge sender) and a black 3 wire connector to
>power the pump. Go figure. This looks to be brand new and may be what
>was replaced in August- not the main pump as stated in the shop bill.
>I will have to get under this thing somehow and try to find the main
>pump. There's a round cover on the drivers side which is, I guess, the
>tank sender for the second half of the gas tank- just one white
>connector with two wires. The plot thickens.
>
>>You need to check the main pump. (The one in front of the left rear tire)
>>Disconnect the rubber line from the cold start valve or the firewall end of
>>the fuel rail.
>>The Bentley manual also recommends checking the fuel pressure at the fuel
>>rail.
>>-----
>
>Crossover year!
>My '88 325is had a single pump in the tank, passenger side. The drivers side
>tank opening is not for a pump.
>The fuel filter is under the car, just forward of the rear wheel on the
>drivers side. It may be under a plastic cover.
>Prior to 1987 switch to 1988 "model year", there were 2 fuel pumps (like my
>'86 535i has). That internal fuel pump
>for the Vega is more than enough to get the required fuel pressure at the
>fuel rail. Like I said, it can pressurise the system even without the main
>external pump on my car. You may check the wiring and connector at the top
>of the fuel tank.
>Jumper the fuel pump (at the relay, per the Bentley) to run while you check
>the connectors at the tank lid.
>
>Bill in Omaha
>'86 535i
>

Ok, better weather today,.. Yep, the filter is under a plastic cover
forward of the tank, drivers side. I don't see any other pump. I have
no fuel at the firewall side of the fuel rack. I have no fuel at the
engine end of the filter. If I pull the filter I can pour fuel through
it unoccluded in both directions- at least that's the way it seems to
me. With the filter removed I can pump fuel onto the ground but it
doesn't seem like a constant thick stream. It just comes in spurts.
With the filter removed I can blow through the fuel line from the pump
outlet to where the filter plumbs in. I can blow from the fuel rack
inlet to where the filter plumbs in too. I have to blow pretty hard
but it does pass air. I guess I should pull the pump and check the
sock but it's all supposed to be new. Any idea how to do the current
test with the 3 wire connecter that's fit to the '88 FP? The manual
just gives a procedure for the outboard pump. Thanks again to
everyone- Bill, I'm still trying to download your attachments. I'm
less browser savvy than I used to be.

"cosmo" wrote in message

On Sun, 30 Dec 2007 10:24:59 -0600, "Bill" wrote:
Ok, better weather today,.. Yep, the filter is under a plastic cover
forward of the tank, drivers side. I don't see any other pump. I have
no fuel at the firewall side of the fuel rack. I have no fuel at the
engine end of the filter. If I pull the filter I can pour fuel through
it unoccluded in both directions- at least that's the way it seems to
me. With the filter removed I can pump fuel onto the ground but it
doesn't seem like a constant thick stream. It just comes in spurts.
With the filter removed I can blow through the fuel line from the pump
outlet to where the filter plumbs in. I can blow from the fuel rack
inlet to where the filter plumbs in too. I have to blow pretty hard
but it does pass air. I guess I should pull the pump and check the
sock but it's all supposed to be new. Any idea how to do the current
test with the 3 wire connecter that's fit to the '88 FP? The manual
just gives a procedure for the outboard pump. Thanks again to
everyone- Bill, I'm still trying to download your attachments. I'm
less browser savvy than I used to be.
-----

Summary: If your auxilliary fuel pump (in-tank pump) is shot, this is an
inexpensive way to replace it. The mod removes the aux pump assembly from
the fuel tank, dismantles the pump from the assembly, and replaces the pump
with a aux fuel pump from a 1976 Chevy Vega.

Tips: This task will go much smoother and faster for you if you get all the
tools and parts ready before you start. You're installation will be better
if you do. Give yourself plenty of time to work, so you don't feel rushed.

Tools Required:

· Rachet

· 8mm socket

· Regular screwdriver

· Phillips screwdriver

· Dremel with sanding/grinding disc - or - fine metal file

Optional Tools Recommended:

· Soldering Iron

· Solder

· Soldering paste

Parts Required:

· Auxilliary (in-tank) fuel pump for a 1976 Chevy Vega (2.2 liter) -
$41.00

· Cable ties $1.00

· Two 3/4 inch hose clamps

· One 1 inch hose clamp

Time Required:

· 30-60 minutes

TEXT ONLY INSTRUCTIONS

1. Open the trunk, remove the carpet, and remove the 3 screws holding the
cover on to access the auxilliary fuel pump.

2. Disconnect the two electrical wire harnesses. One is to the fuel pump
assembly (2 pin) and the larger (3 pin) is to the fuel sender unit.

3. Remove the four nuts and washers securing the fuel sender unit. We
will remove the fuel sender unit to facilitate removal of the fuel pump
assembly. Set the nuts and washers aside for now. You will re-use them.

4. Slide the sender out until it is barely in, then tilt it to let it
drain. Let it drain for several minutes. The holes on the bottom are very
small. After several minutes, pull it out completely and set it somewhere
dry and clean.

5. Remove the six fuel pump assembly mounting bolts. Disconnect the two
fuel lines. Save the metal bands that are underneath the hose clamps. You
can throw the old hose clamps away, you should replace them with new ones.

6. Here's the fuel pump assembly.

7. Let the fuel completely evaporate from the assembly before starting
this step. When it is completely dry, carefully file off the tops of the two
rivets that are holding the electrical terminals in place. Be careful not to
damage the terminals, since we will re-use them to connect to the new pump.

8. Here you can see the rivets have been filed off, and the terminals
broken free.

9. The grounding strap is connected to the assembly with a screw mounted
to a clip nut. Remove the screw and set the screw and the clip nut aside,
along with the grounding strap. We will re-use all these again later.

10. Disconnect the fuel pump from the small portion
of rubber hose and set the assembly aside for now.

11. Under the old pump is a filter screen piece - on
the bottom is the mounting screw. Remove this screw, then gently wiggle the
screen filter free from the old pump. You can discard the pump now.

12. Here's the screen filter.

13. Remove the old bit of hose from the assembly. The
new pump should have come with a new replacement piece of hose that you can
use.

14. Here's the new pump box.

15. The new pump - remove the fuel intake cap.

16. Here's the "accessories" that came with the new
pump. We'll need the hose - that's all.

17. Attach the new piece of hose to the new pump.

18. Attach the new bit of hose (with the new pump)
onto the assembly exactly how the old pump was mounted. I then used some
cable ties to secure it. Reattach the clip nut, grounding strap, and screw
to the assembly. You will need to reattach the screen filter to the bottom
of the pump. You should be able to use the 1 inch hose clamp to secure it to
the bottom of the pump, or use some cable ties to hold it on. You cannot see
the screen filter in this picture, but you can see I've attached it in step
21. Not attaching this screen filter will most surely cause premature
failure of your new vega fuel pump.

19. Now we're ready to attach the wires. We need to
make sure we get the polarity correct, since most electrical pumps will run
IN REVERSE if the polarity of the wires is reversed. This would not be
helpful to your fuel situation, and may damage your new pump. In the next
picture (step 20) you can see that the polarity of the terminals on the pump
is labeled on the pump in a very inconspicuous place.

20. It was very hard for me to see the polarity
marked on the pump, but here you can see where I found the + mark. The -
mark was in the same place on the opposite side. Obviously, you should wire
the grounding strap to the - side and the black wire that comes down from
the top of the assembly to the + side. When attaching the positive cable, it
may be tight. You shouldn't wire it if it is too tight - it could cause the
cable to break and the pump will then not work. There are three things you
can do (in this order) to get it to reach: 1) push the new bit of hose
farther onto the assembly, thereby decreasing the distance from the cable to
the positive terminal, 2) cut a portion off of the new bit of hose and
reattach the new fuel pump, thereby decreasing the distance and providing
slack, or 3) solder a longer wire and new terminal on to replace the
original wire. - I did both #1 and #2, and had just enough length to connect
it without stressing the wire.

All done. Installation is reverse of removal. Use your new 3/4 inch hose
clamps when reattaching the fuel lines. Then fire it up.