Car died in middle of nowhere in rain storm

[xtmsports]

Hey guys,

I was on a mountain highway at night in the middle of a rain storm. All of a sudden, my trusty bimmer did the unthinkable..it stopped.

The engine just cutout, kind of like when you run out of gas.

I noticed earlier during the day, there was a hissing sound coming from the rear trunk of the car. What could possible we back there that would cause a hissing sound?

Anyways, I "think" that may be related to my problem. Anyways, the engine cranks like it wants to start, but maybe its not getting fuel or something.

Maybe the fuel pump died? How would I go about troubleshooting to see if the fuel pump is the problem?

Another thing, when I turned off the ignition today, the oil pressure light would come on for about 5-10 seconds after I pull the key out of the ignition.

Maybe this is related? Please help.

Thanks

[Kalevera]

I'd physically inspect the hoses running out of the tank and around the fuel filter area.

Open the trunk, pull out the insulation on the floor, remove the access panel covering the fuel pump assembly and have a look at the hoses. If everything looks okay down there, jack up the rear pass side and have a look at the fuel filter and lines surrounding it.

Did it just *DIE* or did it sputter out? Seems weird that it would just DIE die if the fuel delivery was the issue.

best, whit

[xtmsports]

It kind of sputtered. I stepped on the gas pedal and the speed didn't increase, so I realized something was wrong and coasted to the shoulder, then I was able to go about another 200 feet and it just died out.

What would be a good indication that the fuel pump died?


Also, over the past couple of months, occassionally, if I fail to crankk the ignition long enough to get the car started(3 seconds) on the first attempt, the second attempt will start the car, but the car idle will want to cutoff unless I give it more gas, eventually after about 5 minutes of giving it gas(2500RPM) it will be okay and I wont have any problems for weeks, then it will happen once again..and then fix itself....etc.



I'd physically inspect the hoses running out of the tank and around the fuel filter area.

Open the trunk, pull out the insulation on the floor, remove the access panel covering the fuel pump assembly and have a look at the hoses. If everything looks okay down there, jack up the rear pass side and have a look at the fuel filter and lines surrounding it.

Did it just *DIE* or did it sputter out? Seems weird that it would just DIE die if the fuel delivery was the issue.

best, whit

[Javier]

just locate the fuel pump relay, bridge the power contacts, and go back to the trunk listening for the pump running sound.

The hissing you described is the pump, but not necessarily means it is broken. Mine has been hissing for about 5 years.

For 1990 535i, F23 is the pump fuse (check it is OK), locate relay K201 in the right hand corner of the engine bay, the box with the Motronic. There is 3 relays in the center. The one closest to the engine is the pump relay. Bridge the relay socket contacts corresponding to relay pins 87 and 30. Pump should start immediately if F23 is OK.

Javier

[xtmsports]

Checked F23 fuse, Okay.

I don't know which relay is the fuel pump relay.

However, I checked the voltage on pin 1 and 3 on the fuel pump and got good voltage at the fuel pump connector.

Does that definitely mean that the fuel pump is dead?


Thanks.


just locate the fuel pump relay, bridge the power contacts, and go back to the trunk listening for the pump running sound.

The hissing you described is the pump, but not necessarily means it is broken. Mine has been hissing for about 5 years.

For 1990 535i, F23 is the pump fuse (check it is OK), locate relay K201 in the right hand corner of the engine bay, the box with the Motronic. There is 3 relays in the center. The one closest to the engine is the pump relay. Bridge the relay socket contacts corresponding to relay pins 87 and 30. Pump should start immediately if F23 is OK.

Javier

[infinity5]

I don't know which relay is the fuel pump relay.


locate relay K201 in the right hand corner of the engine bay, the box with the Motronic. There is 3 relays in the center. The one closest to the engine is the pump relay. Bridge the relay socket contacts corresponding to relay pins 87 and 30. Pump should start immediately if F23 is OK.


the fuse info is printed on the top of the fuse cover, i dunno about the relays though.

the more i learn about my car, and knowing what is still stock, i've resolved to purchase a water pump, fuel pump, fuse set, fuel lines, radiator hoses, and maybe a half dozen other components and just keep them in my trunk anytime i drive anymore than a few miles from my home. :)

[Javier]

fuel pump pins at the connector are 4 and 5, as 1, 2 and 3 are for the sender unit (Fuel gauge and reserve light). Yes I believe you have 12Vdc from 3 to 1, nothing to do with the pump.

Suggest to follow the instructions, identify fuel pump relay K201, in the black box at the right hand corner of the engine bay formed by the firewall and the fender. You will have to loose some Philips screws, look for a piece of bare cooper wire, and jump relay socket holes corresponding to pins 30 and 87 of relay (relay pins are identified). Go back and listen for the pump hissing. If not, it is fried. You can also check for voltage from 4 to 5.

Javier

Edit: If you are scared about not having identified K201 properly, just test resistance between socket hole corresponding to pin 87 and fuse F23. Should be 0 ohm.

[xtmsports]

Thanks for the information Javier. I will check out connector 4 and 5 at the fuel pump connector.

My other issue is locating the pump relay. The black box has many relays, and I don't know which one is the pump relay to test. Perhaps somebody may have a diagram they can post to show me which relay is the fuel pump relay.

Anyhow, it sounds to me that as long as I have voltage at the fuel pump connector, then I can be sure that I need a new fuel pump.

But if I don't have voltage at the fuel pump connector, then I should try to locate the fuel pump relay and trouble shoot the problem in between the relay and the fuel pump connector.

Thanks everybody for the help!


fuel pump pins at the connector are 4 and 5, as 1, 2 and 3 are for the sender unit (Fuel gauge and reserve light). Yes I believe you have 12Vdc from 3 to 1, nothing to do with the pump.

Suggest to follow the instructions, identify fuel pump relay K201, in the black box at the right hand corner of the engine bay formed by the firewall and the fender. You will have to loose some Philips screws, look for a piece of bare cooper wire, and jump relay socket holes corresponding to pins 30 and 87 of relay (relay pins are identified). Go back and listen for the pump hissing. If not, it is fried. You can also check for voltage from 4 to 5.

Javier

Edit: If you are scared about not having identified K201 properly, just test resistance between socket hole corresponding to pin 87 and fuse F23. Should be 0 ohm.

[infinity5]

i could be mistaken, but you might be looking in the wrong electroncis box for the fuel pump relay. i believe the one javier is talking about is on the passangerside, and is *screwed* down. it contains the computer stuff, not fuses. in fact i think there are only maybe 3 relays in it. (looks at his bentley's black and white pics). there should be 3 relays, in a straight line. one close to the fender, one in the middle, and one close to the engine. check the engine-close one....

man, the bentley manual has a really nice diagram of all this, including a pic of the bottom of the relay displaying each pin and its number :)

[Javier]

at the pump connector. Unless engine is running, pump is kept off. Silly? Not that much. When you turn on the key, the pump turns on, once, momentarily, just to pressure up the system, then Motronic waits for the CPS signal to inform engine is running in order to turn on the pump permanently (as loon as engine keep running). Guess it is a safety criterion.

So if you go back to your car and there is no voltage from 4 to 5, it will means nothing.

Think last post from infinity5 clarifies where to locate the pump relay. You have never confirmed us yours is a 1990 535i, took info from previous threads, so I could be mistaken. For 1990 535i info is accurate, 3 relays in a row, the closest to the engine is the pump relay.

[xtmsports]

Thanks to everybody for their help. It turns out that it was the fuel pump. I picked up a used fuel pump froma slavage yard and it started right up.

One question though, I have a 535i, but the fuel pump I got was from a 525. Although it works, I was just wondering it there are ANY negative factors by using the 525 fuel pump for the 535i. The fuel pump for the 525 doesnt look exactly like the fuel pump from the 535i.

The actualy fuel pump/cylinder part is completely different on the 525i. The one from my 535i is an aluminum canister, whereas the on from the 525 is part aluminum and part plastic and is a little bit smaller. Just wondering if that has any performance issues.

I called Autozone and Kragen and they verified that their replacement part numbers for both the 525 and 535 are the same.

But I trust you guys a hell of a lot more.

Thanks again.



at the pump connector. Unless engine is running, pump is kept off. Silly? Not that much. When you turn on the key, the pump turns on, once, momentarily, just to pressure up the system, then Motronic waits for the CPS signal to inform engine is running in order to turn on the pump permanently (as loon as engine keep running). Guess it is a safety criterion.

So if you go back to your car and there is no voltage from 4 to 5, it will means nothing.

Think last post from infinity5 clarifies where to locate the pump relay. You have never confirmed us yours is a 1990 535i, took info from previous threads, so I could be mistaken. For 1990 535i info is accurate, 3 relays in a row, the closest to the engine is the pump relay.