Fuel pump is dead

[Roysneon]

While looking for the fuel leak near the tank on my 84 318i, I realized my pump wasn't doing anything.


I checked voltage to the pump, gets power when cranking the car over, but none when ignition is turned on. Is this right? I battery tested the pump and got nothing, so I'm assuming it's toast. Also, the leak seems to be coming from somewhere high up on the tank on the driver's side. I'm assuming it has something to do with the return, but I'm not sure.

Either way it certainly appears that I need to replace the external pump, and drop the tank. It looks as though I'll have to drop a lot of the rear suspension/exhaust/driveshaft to get the tank out. Is it really going to be that big of a PITA to get the damn tank down to check on this leak?

Probably noob questions, but I've never worked on an E30 before.

[Jean]

Yep, dropping the tank sucks. You can probably go away with removing just the driveshaft/exhaust...and leave the rear suspension alone. It helps that he early 318i tank is on a small side.

[jlevie]

I checked voltage to the pump, gets power when cranking the car over, but none when ignition is turned on. Is this right?

The is the way it should be. The pump is controlled by the DME and only operates when the DME sees timing data from a rotating engine.

Before dropping the tank, remove the back seat and access plat and see if the leak is where the level sensor mounts in the tank. As Jean stated, if you do have to drop the tank you'll have to remove the exhaust and drive shaft.

[Roysneon]

So what are my options for pumps? They're looking pretty damn pricy on Bimmerspecialist/Pelican parts. What about a Walbro 225? I do plan to do some kind of swap this winter, likely an m30. I'm sure the Walbro won't be needed but couldn't hurt if it was available.

The car is about an hour away from me at the only garage I have access to, so next time I'm down there I'll check the level sensor then look to locate the leak.

[Kershaw]

ordering from blunt was ~$160 shipped to me in md.

[Roysneon]

Ok, I have the access panel off and there's alot of moisture on top of the tank. And it def. smells really strongly of gas. (either fumes from that or the Heineken is making me dizzy). I'm thinking there is a leak around where the supply pump drops into the tank. There is also a large hardline to the left (passenger's side) of the pump that seems pretty corroded and is also wet. What exactly is that line for?

The gas poured out when I was swapping wheels and had the passenger's side jacked up, so I'm pretty sure it's the tank itself somewhere, because if it were a line, it would stop leaking once the line itself was emptied, wouldn't it? It leaked out a LOT of gas.

[Ceeker]

e30 tank typically leak from the seam or from the metal fuel lines above; depending on where you live. If you live like me in snowy area and salt is used to deice the road then most likely one or both can happen since water sits up on the top and gets trapped gradually rotting stuff out. If it is a seam leak keep the tank at 1/2 full. but if it isn't then you'll be dropping the tank; I've never seen an e30 tank rust out to the point of having a hole. but if you are leaking that much. better stop driving it. In any case if you go to that much trouble you might as well get the tank epoxy resin coated if it is salvageable Cheaper then a new tank and will last FOREVER! maybe a 100-200 at most. I did this with my 91/318is. Lines are a very common issue up top. Fuel pumps start to go around 200k approx. (125,000 miles)

[Roysneon]

Yep, leak is not from fuel level sensor guage. Any time the car is elevated on the passenger's side the fuel starts pouring out. I'm just going to buy a good used tank and a tested good fuel pump so I can hopefully get this car on the road this month.