I think my fuel pump is abt to shit the bed

[Stanley Rockafella]

Ever since I bought the car several years ago, I noticed that it runs better and starts faster when the tank is over 1/2. Sometimes I'd hear this sucking sound that sounded like a rocket taking off. The sound would go away, but for the most part the car ran alright.

Now I'm noticing longer starts are very consistant regardless of how much fuel I have or how hot or cold the engine is.

I've replaced all the tune up parts incl.
fuel filter, air filter, cap, plugs, wires, rotor etc.

any other ideas on what it could be? is there a check valve inside the fuel pump? Considering it's the orig pump since 1988 and has about 170k miles on it, I think it might be time for a replacement?

[Stanley Rockafella]

Also, is there any specific pump I shoudl order? Is one any better than any other?

Bosch vs. VDO, vs. Beck Arnley?

thanks in advance

[jlevie]

VDO is the OEM maker and what I'd use.

[Stanley Rockafella]

Also, wtf is a "fuel sending unit?" isnt' this the same as the fuel pump?

looks very different than the fuel pump in the pics and is much cheaper. What does it do?

thanks again

[dnguyen1963]

I use Tre fuel pump. Fuel sending unit is a mechanical device that tell you how much fuel is left in the tank. It is a long metal tube with a floater inside.

[Stanley Rockafella]

I use Tre fuel pump. Fuel sending unit is a mechanical device that tell you how much fuel is left in the tank. It is a long metal tube with a floater inside.

And how do you like it? is it similar to the OEM one?

[dnguyen1963]

Very quiet...works well so far. I bought an Airtex pump and that lasted only six months. There are quite a few members here using Tre pumps and happy with them. BTW, use a piece of fuel hose to connect the pump to the fuel line. Do not use the original connector because the rubber septa do not give a good seal.

[drumad]

I'm in the same boat as you. Car died on me on the hwy. Going to do some diagnostics per the bentley first. Hell, it might be an electrical issue.

[5Toes]

Walbro 255 is a good option too IIRC

[Stanley Rockafella]

BTW, use a piece of fuel hose to connect the pump to the fuel line. Do not use the original connector because the rubber septa do not give a good seal.

Anyone have pics of this? what size hose is it? and how much length do I need?

[dnguyen1963]

Anyone have pics of this? what size hose is it? and how much length do I need?

Here is the link...

http://www.blunttech.com/ShopByVehicle.epc?q=&yearid=1988@@1988&makeid=31@@BMW&modelid=976%3ABT%7C5%3AED%7C66%3AMBC%7C168@@325i%20Sedan&catid=240737@@Fuel%20Delivery&subcatid=240792@@Fuel%20Hose&applicationid=W0133-1661978@@Fuel%20Hose&mode=PA

You need a 3-4" piece of tubing.

[Stanley Rockafella]

Oh shit, big trouble now guys...

So I replaced the pump and all was well...or at least I thought.

After replacement I went to fill with gas. After filling I got back into the car and it REAKED with gas fumes.

I proceeded to drive home then once I got home I removed the rear seat cushion to find that the new pump and the top of the tank were COVERED in gas.

I know there's the rubber o ring on the pump, and I ensured it was in place when replacing the pump. I also know that the pump was pushed down as hard as i could when putting the new one in. I also reaplaced the rubber hose with a new piece and with new clamps too. I know it's not that hose as I never had any problems with that smell after I started the car to check for leaks (which there was none).

Should I have the car towed into a shop to have them use the BMW tool to seat the new pump in properly so it doesn't leak gas all over the place? What can I possibly do? I really feel unsafe driving acar with raw gas around the electrical connections for the fuel pump :(

[Stanley Rockafella]

Could it be the sending unit that's leaking? is there a gasket that's separate for it??

thanks

[dnguyen1963]

Take a pic of the top of the tank so we can see what you are dealing with. On my '88 325ic, I need a rubber hammer and a screw driver to seal the pump completely (apply a thin coat of silicon grease to the o-ring before tightening the pump). The sending unit does need a rubber o-ring, or it will leak. The groove is pretty deep for the rectangular shaped o-ring so make sure it is seated correctly before you tighten the sender unit to the pump assembly. BTW, when you put the pump assembly into the tank you should rotate it slowly until it drops into the tank by itself. Only then you should proceed with tightening it.

[Stanley Rockafella]

Thanks for the response. Unfort. my camera is currently inop.

As for the pump, it's slightly off to the side, so it's not rotated enough. I strongly think this is the issue.

Honestly I didnt' think this procedure would be so involved. I didn't think the rubber o ring had to seal against actual fuel, I thought it was just there for the vapours.

I'm gonna attempt to try what you mentioned to see if it has any effect (screwdriver and rubber hammer).

thanks for the help