944 S2 Fuel pump relay?
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Hi There
I have a UK 89 944 S2. Had some problems a while bach whereby the car would just cut out as I was driving along. Turn the ignition off and back on a couple of times and it would generally start fine and I would be on my way. Also I would sometimes hear a buzzing when I first turned the ignition on. Asked the question on this forum and was told it was most likely the fuel pump relay. Just recently it's been doing the same thing again and for the last couple of days it's been a slightly different problem. It starts fine, but when I go to give it a rev it won't go past 2000 rpm, just splutters and drops down to about 1000rpm where it will run fine. Then revs up to 2000 again same story just as if someone were pulling the high tension lead off and putting it back on again. This doesn't happen all the time though, as today I was driving it all morning and it was fine and only started playing up this afternoon. So I thought, right it's about time I replaced the fuel pump relay. On inspecting the fuse box I can't find a fuel pump relay. There is however a DME relay, is this what people may refer to as the fuel pump relay and does this problem sound like it may be related to said relay?
Any help would be much appreciated.
Thanks in advance
Adam
I have a UK 89 944 S2. Had some problems a while bach whereby the car would just cut out as I was driving along. Turn the ignition off and back on a couple of times and it would generally start fine and I would be on my way. Also I would sometimes hear a buzzing when I first turned the ignition on. Asked the question on this forum and was told it was most likely the fuel pump relay. Just recently it's been doing the same thing again and for the last couple of days it's been a slightly different problem. It starts fine, but when I go to give it a rev it won't go past 2000 rpm, just splutters and drops down to about 1000rpm where it will run fine. Then revs up to 2000 again same story just as if someone were pulling the high tension lead off and putting it back on again. This doesn't happen all the time though, as today I was driving it all morning and it was fine and only started playing up this afternoon. So I thought, right it's about time I replaced the fuel pump relay. On inspecting the fuse box I can't find a fuel pump relay. There is however a DME relay, is this what people may refer to as the fuel pump relay and does this problem sound like it may be related to said relay?
Any help would be much appreciated.
Thanks in advance
Adam
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On my 87S the DME and fuel pump relay are the same, They can cause some really goofy things to happen. They're pretty cheap $20 US, I've learned to carry a spare also, they can be hard to find on the weekend.
Another fix to weird DME problems is to clean the grounds to it.
Another fix to weird DME problems is to clean the grounds to it.
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Thanks for the reply.
Just took the DME relay out and re-soldered the connections. Guess I won't find out if I've solved the problem until it gets hot.
Thanks again
Just took the DME relay out and re-soldered the connections. Guess I won't find out if I've solved the problem until it gets hot.
Thanks again
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Hi Adam,
I'm in th UK to. The fuel pump relay is the DME relay, and yes you can re solder the joints inside were they look dried out and brownish. There is a big articale in this months 911 World mag. You can also get the original part from Porsche for £20 which is what they recommend. When the relay get hot the sloder joints fail and cool down they reconect. Good luck!
You going to the TIPEC festival on the 18th July?
I'm in th UK to. The fuel pump relay is the DME relay, and yes you can re solder the joints inside were they look dried out and brownish. There is a big articale in this months 911 World mag. You can also get the original part from Porsche for £20 which is what they recommend. When the relay get hot the sloder joints fail and cool down they reconect. Good luck!
You going to the TIPEC festival on the 18th July?
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Thanks Andriko.
I re-soldered the joints and it was fine except earlier I fired it up and it was running as if on 1 cylinder. Turned it off and started it again and it was fine. I'm begining to think it's something else, but will purchase a new relay anyway.
Hadn't planned on the TIPEC festival, as I'm not sure what it is.
Thanks again.
I re-soldered the joints and it was fine except earlier I fired it up and it was running as if on 1 cylinder. Turned it off and started it again and it was fine. I'm begining to think it's something else, but will purchase a new relay anyway.
Hadn't planned on the TIPEC festival, as I'm not sure what it is.
Thanks again.
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I think the new relay is a 993 part number, so hopefully it's an improved unit. I've had one fail in each of the 944's I've owned ('86 951 and '89 S2). The one in my S2 failed at about 70k miles. And I believe you're correct; the DME relay does control the fuel pump.
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