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Car Won't Start - Help - Fuel Pump Relay?

14K views 24 replies 7 participants last post by  e36is 
#1 ·
1993 325is
90k miles

I'd appreciate it if anyone can help me with this. My car has not been running for about a week and it's already gotten broken into.

My car didn't have any problems before, but about a week ago the car didn't start on first try. It turned over but didn't start. The 2nd try it started. I drove about 2 blocks and the car died and would not start since. Car turns over, but seems like it's not getting fuel? I was thinking it was the fuel pump relay.

I couldn't find a "fuel pump relay" and I heard the DME relay is a common failure. Not really knowing what parts to order I got:

1. Fuel Injection relay; 12V-10/30W; W/ Diode; 6 prong connector - PN 61 36 384 364

2. Fuel Injection relay/DME relay for Motronic; White w/ 5 prong connector - PN 61 36 1 729 004

The first fuel injection relay I could not find where in my car it would be compatible. I looked at all the fuse relays in the box in the engine compartment and none fit.

The 2nd fuel injection relay/dme relay I found where to replace, but it made no difference. No start.

Any advice?
 
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#6 ·
Originally posted by Dudesky_E36@Aug 20 2005, 12:56 PM
http://www.pelicanparts.com/bmw/techarticl...ode_Reading.htm
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I tried to check the default codes, but it didn't work.

I turned the ignition to the on position, stepped on the gas pedal 5 times within 5 seconds, but I didn't get any light flashes. They are supposed to flash at the console where it has the gas mileage, temp, and other info right?

What am I doing wrong?
 
#7 ·
Originally posted by Delmarco@Aug 21 2005, 09:14 AM
http://www.pelicanparts.com/bmw/techarticl...6-Fuel-Pump.htm

DIY section folks...its all there!
good luck...
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Delmarco, that's instructions for installing a fuel pump. I don't think that is my problem although, that is where I intended to go if the fuel pump relay didn't work.

My problem right now is seeing if I got the correct parts for the fuel pump relay and dme relay. I ordered the above parts and only one fit, the other wouldn't fit anywhere.

ANYONE HAVE A DIAGRAM OF THE RELAYS?
 
#9 ·
Originally posted by e36is@Aug 21 2005, 12:31 PM



I tried to check the default codes, but it didn't work.

I turned the ignition to the on position, stepped on the gas pedal 5 times within 5 seconds, but I didn't get any light flashes. They are supposed to flash at the console where it has the gas mileage, temp, and other info right?

What am I doing wrong?
[snapback]371330[/snapback]​
You're looking at the wrong thing. You're referring to the OBC in the center console, it's the Check Engine light by the speedometer that flashes.
 
#10 ·
Originally posted by Dudesky_E36+Aug 21 2005, 09:25 PM--><div class='quotetop'>QUOTE(Dudesky_E36 @ Aug 21 2005, 09:25 PM)</div><div class='quotemain'><!--QuoteBegin-e36is@Aug 21 2005, 12:31 PM



I tried to check the default codes, but it didn't work.

I turned the ignition to the on position, stepped on the gas pedal 5 times within 5 seconds, but I didn't get any light flashes. They are supposed to flash at the console where it has the gas mileage, temp, and other info right?

What am I doing wrong?
[snapback]371330[/snapback]​
You're looking at the wrong thing. You're referring to the OBC in the center console, it's the Check Engine light by the speedometer that flashes.
[snapback]371429[/snapback]​
[/b][/quote]


Thanks. It doesn't give me any codes. It just has a flash, off, then short flash - which is supposed to be no codes right?

What's the tall black relay? It's about twice the height as all the others.
 
#12 ·
the fuel pump relay is located next to ur fuse box. its covered by a black cover. there are 3 relays located under this cover. its either the first one or the second one from the left, either an orange or a white color relay. But, try this first. get a friend to hit as hard as they can on the rear passanger seat where the fuelpump is located. just have him punch the seat, While you try to start your car. then try changing the relay. then if that doesnt work, change the fuel pump it is a 30min change. goodluck! -vince
 
#13 ·
Vince, thanks for the reply. I actually stopped by the dealer earlier today and they were kind enough to give me a relay diagram. And you're right, I missed the 3 fuses under the panel.

So a question for you:
On the diagram, the middle fuse is the "ENGINE CONTROL MODULE RELAY." Is this the same as the "Fuel Injection relay/DME relay for Motronic; White w/ 5 prong connector - PN 61 36 1 729 004?" Seems to match up without problems.

And the relay to the left of it (farthest from the driver) is the "FUEL PUMP RELAY (K6301)." Is this the same as the "Fuel Injection relay; 12V-10/30W; W/ Diode; 6 prong connector - PN 61 36 384 364?" The prongs match up but the new part has an extra prong.

I was going to buy a fuel pump today just to see if it worked, but the dealership is out of stock until Wednesday. So I'll do it then.

I'd like to know about the fuses, since the FUEL PUMP RELAY had some minor corosion. I tried swapping them out like above, but car still wouldn't start.

Well, I'll post what I find so if anyone else has this problem they won't have to go through all the hassle I went through. And I imagine this is a pretty common problem. I'd appreciate it if anyone who knows if the parts are correct would post. Thanks.
 
#14 ·
fuel pump relay and fuel injection relay are different things so I dont think it would work. get the correct relay and try again. if it still doesnt it is the fuel pump. im pretty sure its the fuel pump in the first place and not the relay. but again try getting the correct relay first. -vince
 
#15 ·
Originally posted by vincentwashere@Aug 22 2005, 08:34 PM
fuel pump relay and fuel injection relay are different things so I dont think it would work. get the correct relay and try again. if it still doesnt it is the fuel pump. im pretty sure its the fuel pump in the first place and not the relay. but again try getting the correct relay first. -vince
[snapback]371705[/snapback]​
The fuel pump relay is the one with 4 wires going to the realy plug, one of which is red/white stripe. The main relay has 5 wires going to the relay plug, 2 of them are large about 10 gauge in size, the other relay is the oxygen sensor and it has 4 wires with 2 red/white striped wires. These wire colors are for a 94 325iS. Find the fuel pump relay plug, pull the relay out, look at the bottom of the relay and find #s 87 and 30 terminals, match them to the plug holes and make a jumper wire with a male spade terminal on each end .Take the jumper and jump between 30 and 87 terminals. The fuel pump will come on if it's ok. You can here it run if you stick your head in the window and listen, or get someone to set in the rear and they will hear it if it comes on. You can drive it like this to get home. Used to carry a jumper all time in the GTI days.Had a problem a while back with my 94 325IS, basically a no start,starter was turning it fine. Jumped the relay, came home, replaced the relay, had another no start, replaced the fuel pump, car has 140K so I figured it was time. Had a another no start a week later and finally being hard headed as I am checked the voltage at the main relay and had 11.6 volts,went to battery jump connector on the right fender and had 11.6 volts. Checked the battery and it also had 11.6 volts. The started sounded fine with no other problems but the battery was bad. It should have had at least 12.4-12.6 if it was good.Replaced the battery and it's been fat and happy for 90 days.I don't know what voltage the ecu goes to sleep but there is a low voltage limit that it will just quit.I figure with the starter engaged it would cross that limit sometimes.I would check your battery voltage first and if it's low ,charge it and try and start the car. If it starts, check the alternator output. Good luck
 
#17 ·
I didn't get any emails telling me that people responded. I wish I would have checked this board since people replied with some helpful stuff. I already bought a Bentley manual which has been helpful and I've done a lot of work/troubleshooting today b/c my other car has issues now and I need this car running to get to work. I'll get into it more later...

Originally posted by vincentwashere@Aug 22 2005, 09:34 PM
fuel pump relay and fuel injection relay are different things so I dont think it would work. get the correct relay and try again. if it still doesnt it is the fuel pump. im pretty sure its the fuel pump in the first place and not the relay. but again try getting the correct relay first. -vince
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Vince, do you know what the correct relay is? The dealer didn't even know.
 
#18 ·
The fuel pump relay is the one with 4 wires going to the realy plug, one of which is red/white stripe. The main relay has 5 wires going to the relay plug, 2 of them are large about 10 gauge in size, the other relay is the oxygen sensor and it has 4 wires with 2 red/white striped wires. These wire colors are for a 94 325iS. Find the fuel pump relay plug, pull the relay out, look at the bottom of the relay and find #s 87 and 30 terminals, match them to the plug holes and make a jumper wire with a male spade terminal on each end .Take the jumper and jump between 30 and 87 terminals. The fuel pump will come on if it's ok. You can here it run if you stick your head in the window and listen, or get someone to set in the rear and they will hear it if it comes on. You can drive it like this to get home. Used to carry a jumper all time in the GTI days.Had a problem a while back with my 94 325IS, basically a no start,starter was turning it fine. Jumped the relay, came home, replaced the relay, had another no start, replaced the fuel pump, car has 140K so I figured it was time. Had a another no start a week later and finally being hard headed as I am checked the voltage at the main relay and had 11.6 volts,went to battery jump connector on the right fender and had 11.6 volts. Checked the battery and it also had 11.6 volts. The started sounded fine with no other problems but the battery was bad. It should have had at least 12.4-12.6 if it was good.Replaced the battery and it's been fat and happy for 90 days.I don't know what voltage the ecu goes to sleep but there is a low voltage limit that it will just quit.I figure with the starter engaged it would cross that limit sometimes.I would check your battery voltage first and if it's low ,charge it and try and start the car. If it starts, check the alternator output. Good luck
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[/quote]

I replaced the fuel pump today. Still no start. I also didn't hear it running so I jumpered the fuel pump relay as stated in the Bentley manual and what you said above. And then I could hear the fuel pump running, but still NO START.

So my differential right now is:
1. bad ecm
2. bad crank sensor - if it's bad then ecm won't turn fuel pump on
3. and then what you suggested about a bad battery - i guess it's possible that the fuel pump went out and by the time I replaced it the battery is low from the numerous starts. So i'll check on that first thing in the morning.

Anyone know how likely it is that the crank sensor is bad or the ecm?

Anything else I should consider?

And if it is my ecm that is bad, what's the cheapest and quickest way of getting a replacement?

OBD2GURU, thanks for the diagram. I wish I would have checked this board earlier.
 
#19 ·
The fuel pump relay is the one with 4 wires going to the realy plug, one of which is red/white stripe. The main relay has 5 wires going to the relay plug, 2 of them are large about 10 gauge in size, the other relay is the oxygen sensor and it has 4 wires with 2 red/white striped wires. These wire colors are for a 94 325iS. Find the fuel pump relay plug, pull the relay out, look at the bottom of the relay and find #s 87 and 30 terminals, match them to the plug holes and make a jumper wire with a male spade terminal on each end .Take the jumper and jump between 30 and 87 terminals. The fuel pump will come on if it's ok. You can here it run if you stick your head in the window and listen, or get someone to set in the rear and they will hear it if it comes on. You can drive it like this to get home. Used to carry a jumper all time in the GTI days.Had a problem a while back with my 94 325IS, basically a no start,starter was turning it fine. Jumped the relay, came home, replaced the relay, had another no start, replaced the fuel pump, car has 140K so I figured it was time. Had a another no start a week later and finally being hard headed as I am checked the voltage at the main relay and had 11.6 volts,went to battery jump connector on the right fender and had 11.6 volts. Checked the battery and it also had 11.6 volts. The started sounded fine with no other problems but the battery was bad. It should have had at least 12.4-12.6 if it was good.Replaced the battery and it's been fat and happy for 90 days.I don't know what voltage the ecu goes to sleep but there is a low voltage limit that it will just quit.I figure with the starter engaged it would cross that limit sometimes.I would check your battery voltage first and if it's low ,charge it and try and start the car. If it starts, check the alternator output. Good luck
[snapback]372205[/snapback]​
[/quote]

I replaced the fuel pump today. Still no start. I also didn't hear it running so I jumpered the fuel pump relay as stated in the Bentley manual and what you said above. And then I could hear the fuel pump running, but still NO START.

So my differential right now is:
1. bad ecm
2. bad crank sensor - if it's bad then ecm won't turn fuel pump on
3. and then what you suggested about a bad battery - i guess it's possible that the fuel pump went out and by the time I replaced it the battery is low from the numerous starts. So i'll check on that first thing in the morning.

Anyone know how likely it is that the crank sensor is bad or the ecm?

Anything else I should consider?

And if it is my ecm that is bad, what's the cheapest and quickest way of getting a replacement?

OBD2GURU, thanks for the diagram. I wish I would have checked this board earlier.
 
#20 ·
well , its hard for me to diagnose a car without testing myself , but heres some very basic stuff to start






1.- take out one injector plug and with a led test light if not avail use a normal test light (noid light would be better) check for voltage on 1 side (the voltage side will be the one color that all other injectors have in common) should be 12v with ko.

then put the test light to positive 12v and test the other wire in the in the injector cable and check for negative pulse while cranking .


if all tests ok, means that your crank and cam angle sensors are ok.


next steps should be fuel delivery.

get some starting fluid , take the throtle body tube out and while opening the butterfly
(flap) spray some fluid in and try to start it ,if its starts and quickly dies , then you have a fuel delivery problem , check your fuel filter and presure regulator

a blown presure regulator diaphgram will flood the engine so i recomend to take 2 random spark plugs for inspection

ecm are tuff and rarely die , 99% of all dead ecm's i have seen dead are becouse
somebody kill them by doing some dumb stuff , so ecm is the last to consider.


post here any advance or questions.
 
#22 ·
Originally posted by obd2guru@Aug 31 2005, 03:16 AM
post here any advance or questions.
[snapback]373533[/snapback]​
So here is an update:

Battery checked out at 12V. I jumped it anyway, still no start.

No spark. I tried two plugs. So, no spark and no fuel (b/c poor signal from ecm to fuel pump)

So, it's gotta be the ECM or crank sensor right?

I'm trying to check the crank sensor now. Anyone know where the connector for the crank sensor is? I located the sensor, but can't follow the wire back to the connector.
 
#23 ·
Originally posted by theruss1an1@Aug 31 2005, 07:16 AM
There is also a fuel pump fuse, not sure if that has been checked.

Have you tried to jump the car? If it starts probably an alt fried.

K6301 is fuel, k6300 is the main one. Have those two tested if havent already.

Sorry if I reposted anything.

-Serge
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Yes, I check all fuses. Thanks though.
 
#25 ·
If anyone's interested... it was the crank sensor. I replaced it and it started fine. So I needlessly swapped out a working fuel pump. If anyone wants a spare one to keep in case they get stuck, let me know. It is probably the easiest fuel pump to replace.

I still don't know what part number is the fuel pump relay. And the dealer didn't know either.
 
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