Due to major none starting problems I am trying to eliminate a few things. I suspected the fuel pump was not working whilst cranking. I tried bridging pins 87 and 30 at the fuel relay but nothing happened.
I have checked all pins in this relay plug and there is no voltage whatsoever, can anyone tell me where the power comes from to the fuel relay.
Thanks.
No power at fuel relay.
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e301988325i
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Next good idea would be to state age, engine and type of E30. . . 
I said:
Can anyone suggest how to test if the boot lights are staying on with the boot shut?
e30topless said:
lock the wife in there
Can anyone suggest how to test if the boot lights are staying on with the boot shut?
e30topless said:
lock the wife in there
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Brianmoooore
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We don't know what this car is yet, but I'll place my bet that it has a rear mounted battery!
OK sorry, 1987 M3, immobiliser removed as it was suspected the problem, however it made no difference still no spark and no fuel pump. I have checked the power on the bulkhead where I presume the power comes in from the battery, I am getting a reading of 12v on one terminal and 6v on the other.
I have also checked the reading on the crank sensors in the bellhousing, I am getting a reading from left to right as follows, 947,955,74.
I understand the reading on the first two is good enough however I am unsure about the third. It's the one nearest the fuse box I also checked them again whilst cranking and the 947 goes over a 1000, the 955 goes up and then drops to 1.
Any ideas, thinking about changing the main relay next.
I have also checked the reading on the crank sensors in the bellhousing, I am getting a reading from left to right as follows, 947,955,74.
I understand the reading on the first two is good enough however I am unsure about the third. It's the one nearest the fuse box I also checked them again whilst cranking and the 947 goes over a 1000, the 955 goes up and then drops to 1.
Any ideas, thinking about changing the main relay next.
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Brianmoooore
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You should be able to see the wire virtually all the way from the battery to pin 30 of the pump relay.
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Brianmoooore
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Hmm! This suggests your wiring may have been severly bodged!biggee wrote:I will check that out, meantime I have just rigged the immobilser back up, when activated the fuel pump turns on even though there is still no power at the relay or fuse 11 etc. The pump turns on even with no relay in.
Does the pump actually still get power through fuse 11?
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Brianmoooore
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What colour wires (BMW ones, not the alarm ones)?
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Brianmoooore
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Green wire is the ignition switched live from the ignition switch to the ECU and coil +. shouldn't go to fuse 11, or any other fuse.
With this wire disconnected the ECU won't switch on the DME relay, which in turn powers up the rest of the ECU.
There should still be a permanent live on pin 30 of the fuel pump relay though.
The two cut greens in the fusebox need to be soldered together (or you could just bypass it,as any half decent car thief would know, by clipping a wire from battery + to coil +!)
With this wire disconnected the ECU won't switch on the DME relay, which in turn powers up the rest of the ECU.
There should still be a permanent live on pin 30 of the fuel pump relay though.
The two cut greens in the fusebox need to be soldered together (or you could just bypass it,as any half decent car thief would know, by clipping a wire from battery + to coil +!)
It's a lighter green than than the one to the ignition coil. It has a violet stripe on it, I have it temporarily joined together. It all looks original, I wish the idiot who fitted the immobiliser would have cut it a bit lower as its going to real hard to solder. Is it possible to remove the whole bit back to where the fuse is inserted to solder a longer wire on ?
Also you may recall when we previously suspected the immobiliser was at fault I ran a wire from the ignition to coil + and the car started, then if the temporary wire was removed the car started, I suppose this would indicate something sticking.
Either way it will not start now doing this trick, by coincidence tonight I also tried battery + to coil + to no avail.
Also you may recall when we previously suspected the immobiliser was at fault I ran a wire from the ignition to coil + and the car started, then if the temporary wire was removed the car started, I suppose this would indicate something sticking.
Either way it will not start now doing this trick, by coincidence tonight I also tried battery + to coil + to no avail.
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Brianmoooore
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Slight correction to my last post: This is a M3, which uses older versions of the wiring system.
The green wire on these goes directly to the DME relay, rather than using a section of the ECU to switch it on. Other than that, everything else is the same. The permanent live red wire from the battery should first go to pin 30 of the main DME relay, and then loop on to pin 30 of the pump relay.
The green wire on these goes directly to the DME relay, rather than using a section of the ECU to switch it on. Other than that, everything else is the same. The permanent live red wire from the battery should first go to pin 30 of the main DME relay, and then loop on to pin 30 of the pump relay.
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Brianmoooore
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Black sheath on a red wire, except for the big thick wire to the starter motor.
Brian, your right, its red coming into the relay.
I have just checked for voltage at the main relay,
without ignition on 0.09v
with ignition on 4v maximum with a lot of fluctuation.
With the metal cover on the relay I can feel it getting warm, also I have removed the relay cover and the contact does come together and stay together when the ignition is on.
I have just checked for voltage at the main relay,
without ignition on 0.09v
with ignition on 4v maximum with a lot of fluctuation.
With the metal cover on the relay I can feel it getting warm, also I have removed the relay cover and the contact does come together and stay together when the ignition is on.
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Brianmoooore
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The contacts coming together is nothing to do with the red wire - it's the plain green and plain brown on 85 and 86 that are causing that.
You appear to be using a meter to check voltages. That will give you misleading results in many cases, as, under common circumstances it will indicate that a voltage is present where it's not. Use a 5W 12 volt bulb for your testing.
It's beginning to look like the whole engine loom has lost its power supply. If you look back to my first post in this thread you'll see it says: We don't know what this car is yet, but I'll place my bet that it has a rear mounted battery!
This is because the engine loom on cars with rear mounted batteries only, have a fuse in the supply, mounted next to the battery in the boot. It's a fusible link rather than a conventional fuse.
You appear to be using a meter to check voltages. That will give you misleading results in many cases, as, under common circumstances it will indicate that a voltage is present where it's not. Use a 5W 12 volt bulb for your testing.
It's beginning to look like the whole engine loom has lost its power supply. If you look back to my first post in this thread you'll see it says: We don't know what this car is yet, but I'll place my bet that it has a rear mounted battery!
This is because the engine loom on cars with rear mounted batteries only, have a fuse in the supply, mounted next to the battery in the boot. It's a fusible link rather than a conventional fuse.
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Brianmoooore
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There should be two wires coming off the battery + terminal, if the M3 uses the same set up as 325 saloons. The big main cable, and a much smaller one. The smaller one should have a join a few inches from the battery, and the section between this join and the battery is the fusible link.
Both wires should terminate at a 'phantom' battery terminal, mounted on the engine bulkhead behind the front battery tray, where your coolant bottle is. As a temporary check, you can link both wires together here.
Both wires should terminate at a 'phantom' battery terminal, mounted on the engine bulkhead behind the front battery tray, where your coolant bottle is. As a temporary check, you can link both wires together here.
I will check this out tomorrow night.
I have just seen this on another forum where it seems someone was having the exact same problem.
"There is a 50amp Fuse built in to the battery cable that is on the circut you are having problems with. It's in the trunk, you can feel it shrink wrapped on the small power cable running next to the large cable if you remove the plastic cover. It's about 20 inches from the terminal. I had to replace the fuse.
Thanks for your help.
I have just seen this on another forum where it seems someone was having the exact same problem.
"There is a 50amp Fuse built in to the battery cable that is on the circut you are having problems with. It's in the trunk, you can feel it shrink wrapped on the small power cable running next to the large cable if you remove the plastic cover. It's about 20 inches from the terminal. I had to replace the fuse.
Thanks for your help.
Hi Brian,
I could not resist, so I've been out there again, located the fusible link, uncovered the shrinkwrap, everything looked fine, checked for voltage going in 12v, voltage going out, nothing, there is a secondary rubber cover over the fuse which I removed, I then spotted a little crack in the fuse give it a little pull and it seperated.
I bridged the fuse cranked the car and bingo the car fired "joy".
I suppose now I have to ask myself what has caused this, perhaps there is a short somewhere that has caused the fuse to blow.
All this originally started with the car dying on me at speed and not restarting until the next day, then when it did run the power died down on acceleration. Do you think this fuse could still carry power even with a break in it, It did still appear to be whole.
Thanks for your help on this.
Regards, Glenn.
I could not resist, so I've been out there again, located the fusible link, uncovered the shrinkwrap, everything looked fine, checked for voltage going in 12v, voltage going out, nothing, there is a secondary rubber cover over the fuse which I removed, I then spotted a little crack in the fuse give it a little pull and it seperated.
I bridged the fuse cranked the car and bingo the car fired "joy".
I suppose now I have to ask myself what has caused this, perhaps there is a short somewhere that has caused the fuse to blow.
All this originally started with the car dying on me at speed and not restarting until the next day, then when it did run the power died down on acceleration. Do you think this fuse could still carry power even with a break in it, It did still appear to be whole.
Thanks for your help on this.
Regards, Glenn.
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Brianmoooore
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From what you say , it sounds like this could just be an mechanical failure of the fuse, rather than an electrical one. Fits with the intermittent nature of the fault at first as well.
I think nothing more is required than a replacement fuse.
I don't know if they are an exact replacement , but similar fuses are found in 325 E30 saloons, E36's and E34's with mid mounted batteries.
I think nothing more is required than a replacement fuse.
I don't know if they are an exact replacement , but similar fuses are found in 325 E30 saloons, E36's and E34's with mid mounted batteries.