Car Died. Diagnosis?

[Bill R.]

2 years, what posts do you read? First off , liquids don't compress, so there's no compression test for fuel. There is a pressure test however. You have to buy a fuel pressure test gauge from autozone for about 39 bucks, then you have to buy a Brass T fitting and some fuel line and hose clamps so you can T into the fuel line going into the Fuel rail where the injectors are mounted. As shown here the line at the front of the fuel rail is the pressure side from the fuel pump. You want to put your t fitting here at the rubber fuel line connecting to this line. Then while cranking the engine you check the gauge for fuel pressure, 35 to 45 is what your looking for as a minimum. If you have fuel pressure , then you need to buy an extra spark plug and remove one coil from one of your spark plugs, put the extra spark plug into that coil and hold the threaded part of the spark plug against the side of the engine on a good ground. Have someone crank it while checking the plug to see if its sparking. Don't do this after you did the fuel pressure test if you spilled gas all over the place. If you have spark but not fuel pressure check the fuel pump relay in the box on the passenger side where the DME is .

How does one check for spark?


Take the plug out set it down on something stable and crank it? Sorry, I am a noob. And, no...I don't have money to take the car to a mechanic. I am a poor college student. Trying to figure this one out on my own first.

[Bill R.]

needs the least amount of gas to run. The engine at wide open throttle at 90mph needs the most amount of gas to run. When a fuel filter gets plugged up the Engine won't run at high speed because it can't get enough fuel but typically it will easily get enough to run at Idle.... This fuel filter thing is a plot by autozone to sell more filters So the first symptom of a plugged up fuel filter is no high speed power or no high speed period...

I would start with the filter, every time I brought my car to the e34 indy, he insisted on changing it - years of constant problems with e34 filter issues taught him well!

simple and cheap, worth a shot.
Were you low on fuel? Climb a hill?

I ran out of fuel in the 540 a few times, it seemed that because of my driveway (big hill), if I was low, the tilt would empty the tank enough to one end that I couldn't restart it without adding a few gallons.

It sounds like what you described, sputtering, then dead. After refueling a bit, it would crank for a minute before starting up as well, it was not instant, and would chug for 30 seconds before idling smooth.
Good luck.
Surely, the big guns of the forum will be around soon to help you out though!

[liquidtiger720]

Well, the spark works. I didnt have a fuel gauge thing to test the pressure.


No sounds are coming from the pump area either. The fuse is okay. Is there a relay that I am missing/can't find?



Yea, Bill....I read a lot of everything....but for some reason, pressure testing the fuel system was something I never read about, nor could I find it. When it comes to cars....I know nothing, and am very scared to mess with them.

[Bill R.]

terminals 30 and 87 from the fuel pump relay in the ebox as seen here. Take a short piece of wired and jumper from where the relay plugs into terminal 30 and 87, with the key on , go remove the gas cap from the tank and listen to see if you can hear the pump running

The fuel pump relay is k6301 in the picture

Well, the spark works. I didnt have a fuel gauge thing to test the pressure.


No sounds are coming from the pump area either. The fuse is okay. Is there a relay that I am missing/can't find?



Yea, Bill....I read a lot of everything....but for some reason, pressure testing the fuel system was something I never read about, nor could I find it. When it comes to cars....I know nothing, and am very scared to mess with them.

[ThoreauHD]

[liquidtiger720]

Jumped the terminals....and still no sound from the fuel pump. (at least none that I could hear). Is it safe to assume that the pump outright died?


Thanks Bill for the info.

[Kalevera]

Yes, my first thought when reading the initial post was failure of the pump or relay -- a sputtering death usually means there's some kind of spark.

Pull the fuel pump, bench test it to confirm failure. Hopefully the car doesn't have more than half of a tank of gas in it, otherwise -- wear a big and thick rubber glove Wear it anyway, actually.


best, whit

[gmannino]

You can pull out all your spark plugs, easy thing to do, and then try to crank the engine with the fuel relays still plugged in. If your fuel system is working you will smell a very clear amount of fuel, cant miss it. But if you crank it and there are no smells of fuel, you know your not getting fuel in those cylinders. Also if your fuel pump isnt making sounds, then you probably found your problem. You can pull out the fuel pump and send power to it manually to test to see if it indeed it blown out.

Hope ya get it running, its a beautiful e34.

[liquidtiger720]

New fuel pump works like a charm....cept it's kind of noisy, the whine is louder than I thought it would be.

Fuel filter is changed too

[BillionPa]

grab a bottle of lucas upper cylinder lubricant, and put the proper amount in the tank, should shut the pump up.