M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine management => Topic started by: wrx2m42 on April 07, 2010, 09:05:43 PM
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Suddenly my 318is won't start, I've been using it daily for a few years without any problems, came back for a quick lunch break and went back out to my car to find out that it won't start anymore.
Here is what I've diagnosed thus far, keep in mind that I'm no expert with cars. The engine is turning over, except that it won't start. I've checked a few things thus far.
First the fuel pump relay seems to be working well, I hear a clicking noise coming out of it and attempted to switch the relay with the O2 sensors to see if anything came of it.
I removed the air intake to have access to the throttle bodies, added some fuel manually and the engine ran well until it ran out of gas. Does this mean that I can rule out the crank positioner?
At this point I have a feeling that its not electrical but rather a fuel problem, and possibly the pump. I was wondering if anyone could give some insight on other things to check before diving into replacing the fuel pump. Fortunately the car made it back home, unfortunately my complex isn't too kind on letting me work on my car. A quick fix or change MAY be possible, but I'm hoping I don't need to have the car towed and then pay to have something replaced.
Any suggestions?
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I would look at the fuel pump for sure. The small piece of hose in the fuel tank from the pump to the plastic fuel feed distributor unit sometimes fails or cracks also.
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Check the fuel filter. While you have it off, put a bucket under the hose and try to start the car. It should squirt gas out.
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Exactly what doitover said. But where some sort of eye protection if somebody else is starting the car. You don't want fuel in your eyes. If no fuel comes out, change the filter and try again. If still nothing, you have a pump issue. But if fuel does come through, you more than likely have an injector issue such as the relay.
And yes, if the car ran fine with starting fluid, you can rule out the CPS.
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Check the resistance of the crank position sensor. It'll disable the fuel pump relay if it's bad. Should be about 680 ohms. I had the same problem, cleaned the oil & rust off my CPS and it came back to life.
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I don't know if the problem is solved by the topicstarter but i have te same kind of problem.
The only difference is that i have a question about the resistance of the Crankshaft sensor.
My fuel pump relay is working but it won't give a signal to the fuel pump itself so my first thought was that the crankshaft sensor is broken.
I grabbed my multimeter and read it out. It gives out an resistance of 520 Ohm.
Now the confusion ive got ; The bentley(E36) manual says that the resistance should be 1280 ohm with a down/up of 10%. Looks like its broken then.
But then a couple days later i read the Haynes manual and it says it should be 500-600Ohm.
Can someone give me some feedback for this? The sensor is already ordered from Germany and should be here in a couple of days.
I live in the Netherlands,the Germans are our neighbours.
If it isnt the sensor i cannot bring it back to BMW, and it costs me about 135 euro's... thats about 150 dollars or more! :eek: ;)
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The bentley is incorrect 1280 is for the Camshaft position sensor.
haynes is correct 500-600 for the crank pos sensor.
good luck
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The bentley is incorrect 1280 is for the Camshaft position sensor.
haynes is correct 500-600 for the crank pos sensor.
good luck
Hmmm , stupid bentley then ;)
I guess you're right, yesterday i grabbed my multimeter and measured both of the sensors and the readings were like this ,
Camshaft sensor; 1260 Ohms
Crankshaft sensor; 520 Ohms
So it looks like the sensors are OK.
So what's causing my car not to start..
My battery is good ,starter is good, ignitions are good, sensors are OK....
I must admit that the last time i turned the key i didn't heared the fuel pump.
I'm gonna check that , do i have some other options or is that about all?
Thanks for you're help RED IS 91.
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If no fuel, check the fuel pump relay. The crank sensor might just be dirty too. It's magnetic, so it picks up rust and the signal gets inaccurate. Re-adjust it too. It has to be very close to the crank trigger wheel.
I'd check the connectors on the fuel pump too. They can loosen up and not provide enough current to run the pump.
Look closely for any cracked vacuum hoses. They must be tight (especially the big hoses for the idle control valve), air leaks will prevent the engine from starting.
If that doesn't do it, have the fuel pressure tested. The pumps only seem to last about 80-120K miles, and a plugged fuel filter can cause trouble too. Pressure regulators are pretty reliable but have been known to fail.
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If no fuel, check the fuel pump relay. The crank sensor might just be dirty too. It's magnetic, so it picks up rust and the signal gets inaccurate. Re-adjust it too. It has to be very close to the crank trigger wheel.
I'd check the connectors on the fuel pump too. They can loosen up and not provide enough current to run the pump.
Look closely for any cracked vacuum hoses. They must be tight (especially the big hoses for the idle control valve), air leaks will prevent the engine from starting.
If that doesn't do it, have the fuel pressure tested. The pumps only seem to last about 80-120K miles, and a plugged fuel filter can cause trouble too. Pressure regulators are pretty reliable but have been known to fail.
It looks like my fuel pump is broken because i hear no clicking sound anymore when i turn on the key.
I checked for voltage at the relay and the pump itself and that was okay. i got only 1 question about that.
Is it normal that the voltage is a little lower there than directly at the battery?
I know by then it has travelled trough the circuit but the voltage at the battery was 12.6 and at the relais and fuel pump it was 10.8 or so.
The fuel filter has been replaced a year ago by the previous owner.
The mess under the intake as you call it, i replaced that almost immedeatly when i bought the car because there were some cracked hoses.
Thanks for the input Dave , tommorrow i'm gonna do a final test on the pump.
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Voltage should be pretty high. Two volts is a pretty big drop over six feet of wire. I'd figure you might have a bad ground, chafed wire or a flaky pump relay.
Did you do a stomp test?
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Maybe you're right about the relay but i measured it at the seat(?) of the relais and the voltage was also low there. And i hear a clear clicking sound from the relais.
But what is a stomp test Dave? ;)
When i turned on the ignition and measured the voltage at the pump connection this was at most 11 volts , isn't this enough to at least make it turn on?(if the pump is ok)
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One thing you could do is put 12 volts directly to the fuel pump .If it doesn't hum, spin or make noise than it is toast.If you have 11 volts at the pump and it's still not pumping then it's probably toast. Did you try wiggling the connection at the pump?
Usually these pumps last around 150K-180K .
Stomp test for usa cars only
http://m42club.com/forums/showthread.php?t=9513&highlight=stomp+test
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Hmmm. Did you have the battery load tested? Make sure you get a good load test, it might just be that simple. Most car shops around here will do a free battery or alternator tests. I usually do both if I have any questions about the electrical system.
IDK if the Netherlands has a US spec DME/ECU to do a stomp test. You might have to pick up one of those Chinese BMW laptop-based code readers. From what I've seen during my brief time in your country...you have the most 'American' cars on the continent.
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It's been a while and the car sometimes runs great and other times it just won't start.
I did removed the fuel pump and hooked it directly tot 12V.
This seems to work , however the second time i did this the pump did not react.
When i hit it with my nail it began pumping, so it looks like the pump get stuck at certain moments.
@Red IS91, My engine has about 240.000 Km so thats about.... 150.000 miles, so i think the pump has had it longest time then ;)
Desktop Dave, I think my battery is ok, it gives a good voltage and when i crank the car it ignited pretty fast. If there was some fuel to ignite!
You are lucky that you have that 5 times gaspedal push read-out.
A couple of months ago i didn't knew that it was a US spec so i pressed the gas pedal at least 50 times to discover some codes :rolleyes: :D
My car is originally imported from Germany to Holland in 1994, so it has the European kind of DME/ECU with no stomp test.
When hooked the pump externally and run the car, the fuel pump connector gives a voltage of 13,78V so the power to the pump is also correct.
Later on i thought it could be the fuel pressure regulator because it won't start if the car had stand still for a while.
But even without a broken pressure regulater the car would at least start and sputter a little right?
I'm going to look for another pump because hitting the pump every time i start the car is a little stupid...
And you're right, you can see a lot of American cars here.
A friend of mine has a Chevrolet K30 pick-up truck(from the gulf war) and we live in a forest rich enviroment so thats a lot of fun with such a pick up.
It pulls itself through the tickest en deepest mud with no hesitation ;)
Were you here on vacation?
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It sounds like your pump is a goner. I had similar problem on my car, it ended up being a loose connector at the pump. Try unplugging the connector and crimping it JUST A LITTLE with a pair of pliers and then connect/disconnect a few times to clean up the connector pins. If it works, this will buy you some time while you source a new pump. Don't get lulled into a false sense of security, your pump is failing and will need to be replaced.
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Yeah, I'm thinking pump too.
Yep, I was over there on vacation. We only spent a night in Amsterdam, so I didn't get a really good look around. Your country is very beautiful, and very tolerant of some pretty ugly American tourists...of all the places in Europe that we visited it was the easiest to get around if you only speak English. I still have some of your old money around...we went before the Euro.
I'd highly recommend it as a vacation...Amsterdam is a blast. It's up there with New Orleans and New York as my favorite places to be...I'll be back when the kids get a little older.
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I'm already lookin for a new pump, it's indeed one of those parts were you want to be sure of working correct.
Glad you've got a good time in Amsterdam , its a nice city.
I also like the tolerancy in my country although i have the feeling that it's changing a little.
More unneccesary rules and laws , our country is not so big and we've got a relatively large population so the government wants to controle alot these days.
But you wil experience the same thing in America i guess ;)
I find the old Guldens a better lookin money than the euro, and i think a lot of people here will agree with me.
I actually never been to America but i would love to go sometime.
You're country has got so big in such a relatively short time-span, thats pretty interesting... But until i go al my money will flow to the old BMW ;)
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America is big, but you can skip most of it depending on what you like. If you like to party, do New York or LA. If you like to gamble, Las Vegas or New Orleans. If you like the outdoors, Yosemite, Rocky Mountain Nat'l Park, Pacific Northwest, etc. Getting around America isn't nearly as easy as Europe though.
Or head up north to Canada. They're a little like us (just cleaner & more polite)... Toronto is a great city to hang out.