Fuel Pump & Battery Drain Issues

Thanks Percy. The car is in really good condition mechanically (normally). It's garaged when not being driven and only then in dry conditions.

I had actually resorted to disconnecting the battery in the garage between drives because of the suspicions of the alternator. When I did this the car would start first time, every time when I reconnected the battery.

I've had the car in for service in the past 2 weeks and got the guys to check out and replace the old alternator. I tried leaving the the car overnight with the battery connected and it started first time next day. It was only after leaving it a couple of days more that the battery was again drained. This makes me think it's more than just the alt and there is a drain caused by something else.
 
Thanks Percy. The car is in really good condition mechanically (normally). It's garaged when not being driven and only then in dry conditions.

I had actually resorted to disconnecting the battery in the garage between drives because of the suspicions of the alternator. When I did this the car would start first time, every time when I reconnected the battery.

I've had the car in for service in the past 2 weeks and got the guys to check out and replace the old alternator. I tried leaving the the car overnight with the battery connected and it started first time next day. It was only after leaving it a couple of days more that the battery was again drained. This makes me think it's more than just the alt and there is a drain caused by something else.
 
My battery will drain also if I let it set for more than a couple weeks and it is a new battery. I usually disconnect the ground cable if it is going to set more than two weeks without running. That does not happen often. I found there is no current draw on the battery if I pull the fuse that goes to the clock. I think that fuse also goes to the radio which draws power for the memory. I will eventually find out what is specifically drawing current.

My clock doesn't work and I have another working one to replace it. I just have not gotten around to the not-so-fun job of replacement. I am wondering if the non-functional clock may be stuck in the re-firing mode and is constantly drawing current.
 
My battery will drain also if I let it set for more than a couple weeks and it is a new battery. I usually disconnect the ground cable if it is going to set more than two weeks without running. That does not happen often. I found there is no current draw on the battery if I pull the fuse that goes to the clock. I think that fuse also goes to the radio which draws power for the memory. I will eventually find out what is specifically drawing current.

My clock doesn't work and I have another working one to replace it. I just have not gotten around to the not-so-fun job of replacement. I am wondering if the non-functional clock may be stuck in the re-firing mode and is constantly drawing current.
 
G
I am wondering if the non-functional clock may be stuck in the re-firing mode and is constantly drawing current.
Click to expand...

This is possible. Inside the clock there are two little contacts which close when the spring unwinds. When they make contact the activate the rewind coil which applies about a 10-20 degree wind to the main spring and the process starts all over again. If the contacts have closed and the coil it trying to rewind but the mechanism is covered with dirt and congealed oil film it would never rewind and disengage the contacts. When and if you pull the clock put a meter across the single power connector and the body of the clock. If you see anything less than a Mega-ohm or so then this could be the case.

I was able to get my clock working pretty well after taking if out and pulling the back cover. I sprayed the mechanism with disk brake cleaner and put sewing machine oil on some of the gear bearing points (avoid the little ticking part - forgot what it's called) as oil will interfere with it's time keeping. I also used some 400 grit sandpaper to clean the solenoid contacts. Tic-toc-click.
 
G
I am wondering if the non-functional clock may be stuck in the re-firing mode and is constantly drawing current.
Click to expand...

This is possible. Inside the clock there are two little contacts which close when the spring unwinds. When they make contact the activate the rewind coil which applies about a 10-20 degree wind to the main spring and the process starts all over again. If the contacts have closed and the coil it trying to rewind but the mechanism is covered with dirt and congealed oil film it would never rewind and disengage the contacts. When and if you pull the clock put a meter across the single power connector and the body of the clock. If you see anything less than a Mega-ohm or so then this could be the case.

I was able to get my clock working pretty well after taking if out and pulling the back cover. I sprayed the mechanism with disk brake cleaner and put sewing machine oil on some of the gear bearing points (avoid the little ticking part - forgot what it's called) as oil will interfere with it's time keeping. I also used some 400 grit sandpaper to clean the solenoid contacts. Tic-toc-click.
 
Hello again gents. I've finally got the fuel pump relay from BMW. Fitted and she started up for a few seconds but then died. (this happened previously after I'd cleaned up the contacts on the old relay and re-fitted it). All the fuses appear OK, so nothing's blown and the engine turns over cleanly. Any suggestions or ideas are greatly appreciated.

Thanks.
 
Hello again gents. I've finally got the fuel pump relay from BMW. Fitted and she started up for a few seconds but then died. (this happened previously after I'd cleaned up the contacts on the old relay and re-fitted it). All the fuses appear OK, so nothing's blown and the engine turns over cleanly. Any suggestions or ideas are greatly appreciated.

Thanks.
 
Hi Rob, try starting it and be under the car to see when/if the pump stops by touching it, it should be quite obvious when it is running and not.

Otherwise it must be ignition side and I am at a loss there!

Rohan
 
Hi Rob, try starting it and be under the car to see when/if the pump stops by touching it, it should be quite obvious when it is running and not.

Otherwise it must be ignition side and I am at a loss there!

Rohan
 
RobHannett said:
I've finally got the fuel pump relay from BMW. Fitted and she started up for a few seconds but then died. (this happened previously after I'd cleaned up the contacts on the old relay and re-fitted it). All the fuses appear OK, so nothing's blown and the engine turns over cleanly. Any suggestions or ideas are greatly appreciated. Thanks.
Click to expand...

I have several thoughts, none of which are particularly creative and many of which have been culled from this board.

I am not sure why you targeted the relay but will assume, for the moment, you tested the voltage to the relay and then to the pump. There is a brown ground wire attached to the relay, make sure it is connected to a ground!

If the pump stops buzzing or makes odd sounds, there's a couple things to do.

First, test the voltage to the pump relay to make sure it is being energized.

Second, you might want to make sure the pump and the wiring to the pump is in decent shape. Check for 12V at the leads that directly connect to the pump. Next, test the pump itself either by removing it and bench testing it with a 12V source or by testing it directly with two test leads from the battery or another source. Remember to be very careful since you are dealing with fuel and electricity.

If the pump is functioning well, there is quite a bit more to think about.
There are safeguards in the fuel pump circuit to prevent the pump from functioning if the engine dies by shutting voltage to the pump after 1.5 seconds. I don't recall if this is in anyway tied into the oil pressure sensor as it is in a few cars. From memory, it is integrated as part of the ECU, the throttle position switch, the injector trigger points (bottom of distributor) and ignition switch. If your ignition switch is sloppy or if there is corrosion at the fuse box this could be part of your problem. Re check the wiring connections. This may even include the trunk wiring connection to the ECU.

Before you give up, carefully read the thread on intermittent engine cut out. http://e9coupe.com/forum/viewtopic.php?t=3267 There are other references to troubleshooting the injection fuel pump circuit.

hth and good luck!
 
Afterthought

Having mentioned the safety cut out of the fuel pump in the prior post, I wonder if there couldn't be something you overlooked with the ignition side of things. Seems attenuated but a bad condenser or bad coil could mimic a weak fuel pump. If you can get the engine started again and it dies, take an ignition lead and see what kind of spark you get. Yellow? Blue? If its the former, well you see where I am going.

Hth.
 
Thanks. Yes the brown wire is grounded. When I first turned on the ignition the pump buzzed as normal. That's when I was able to start up briefly before it cut out. After that, there's no sound from the pump. I still have ignition, electrics, everything else. This happened on the old relay and the new. The roadside recovery guy suggested it was the relay which is why that's been my first port of call. If it is the pump then I think it's a trip to the local garage as it starts getting beyond my limited expertise.
 
Thanks. Yes the brown wire is grounded. When I first turned on the ignition the pump buzzed as normal. That's when I was able to start up briefly before it cut out. After that, there's no sound from the pump. I still have ignition, electrics, everything else. This happened on the old relay and the new. The roadside recovery guy suggested it was the relay which is why that's been my first port of call. If it is the pump then I think it's a trip to the local garage as it starts getting beyond my limited expertise.
 
RobHannett:

If you remove relay contact and do a short circuit over the terminals the relay closes when energized:

You are then able to hear the pump working for a longer period building up pressure. You are also able to hear gas running back into tank via returnpipe. If possible also measure gas pressure.

This is a simply method for checking functionality of the pump, fuel lines and pressure regulator without engine noise and exhaust fumes :D
 
RobHannett:

If you remove relay contact and do a short circuit over the terminals the relay closes when energized:

You are then able to hear the pump working for a longer period building up pressure. You are also able to hear gas running back into tank via returnpipe. If possible also measure gas pressure.

This is a simply method for checking functionality of the pump, fuel lines and pressure regulator without engine noise and exhaust fumes :D
 
Rob - it's a long shot but I had a similar ignition / fuel pump problem recently. It turned out to be a dodgy earth in the boot area. Lift up the boards and check them all out
 
Rob - it's a long shot but I had a similar ignition / fuel pump problem recently. It turned out to be a dodgy earth in the boot area. Lift up the boards and check them all out
 
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