Porsche Enthusiasts Club Forum

Correction Buycarparts pump is over £200 cheaper than OPC

After going back & forth with the eBay seller, the part arrived & looks just about the same as what I had on the car. He did agree that the OE part number I supplied did match the fuel pump he sent, but kept mentioning he could not confirm it is a match to what I had on the car. At the time I had not taken mine off the car I felt this was irrelevant to compare, due to the fact I had no knowledge what previous owners may had done to the car.

Anyhow, it fitted & worked perfectly. Taken it for a run as well. So far, so good

Now, the fuel sender unit is not reading correctly

this is nothing unusual, have you cleaned the "Rugby Balls" on the back of the gauges, that's the first place to start, secondly you can get the sender out the tank and clean the level wire with carb cleaner or similar as the top part can get covered with fuel gum from years of only half a tank.

a new sender is 944 641 037 01 £140.00

Thanks Waylander.

Let's break this down; what are "Rugby Balls"? I have had the gauge cluster out before. Might as well take out again, as I also have an irritating vibrating plastic noise coming from the rights side of the cluster, to around the vent/switch area which is proving quite a challenge

I took out the sender unit, a cylindrical contraption, where I could not see level wire, like on a regular unit with floating arm; can it be dismantled?

Once out, I turned it upside down & gauge showed nearly full(not completely). Then again in vertical position, it showed empty; completely with low fuel illumination lamp. That's all I did. The tank is presently nearly full but not quite full. But, the gauge with sender in place shows slightly shy of half full. So, I assume the sender unit could have an issue in this area!?

On the rear of the gauges there are two rugby ball shaped lumps of brass / copper held on with two small nuts, these complete the earth paths of the instruments and can become corroded / tarnished over time, this increases the resistance

Undo the nuts and remove the “balls” and clean it all up with some fine wire wool and try it again

On the sender you can remove the white cap off the bottom then you will see the float and wire inside, don’t try to clean it with anything other than spray,

If you look at this
https://www.ebay.co.uk/itm/PORSCHE-944- ... Swgrxey71Q

the second pic shows the back. The rugby ball parts are the balck oval pieces held in with the brass nut. It doesn't matter this is the voltmeter/oil pressure gauge the other looks the same. Remove the nut and pull the black oval piece out and clean the 2 long brass prongs. Often fixes intermittent gauge issues.

Will have a go. Cheers.

Most probably will start with this. Can I use brake cleaner?

Not sure brake cleaner will dissolve that old fuel gum

And you will need a new sealing ring on the sender once you have removed it, and don’t do it up so tight it distorts the tank

So best use Carb cleaner?

Maybe start with the Rugby balls first as not worth ordering a sealing rim on it's own.

Cheers.

Maybe Tar & Glue remover!

Carb or maf cleaner will work the best I think

Doesn't look like I'm making any progress

Took out the rugby balls, which had two prongs that plug into the circuit board, cleaned with fine steel wool & contact cleaner; unfortunately no improvement.

This leads me to believe the sender unit to be at fault. Could give that another go as I didn't use carb cleaner, but again, not really sure what to aim at as could not understand the internals quite well

May have to try & find a used one in future

If you go have a look at clarkes garage they have all the resistances you should be seeing at 1/4 1/2 3/4 and full that might help