struan

Greetings all,
On my current project the external fuel pump is seized solid.
Easy cure to get car running was to fit a new one.
They are quite expensive down here, so my question is, has anyone succesfully refurbished one of these, or should I consider it a disposable item.

ROG100

Struan - it would help if you told us what year car we are dealing with as lots of different pumps were used on the 928 77 to 95.

Pumps are relatively cheap by Porsche standards and we stock all the OEM Bosch types. Let me know the year and I will quote you.

Never heard of a pump being rebuilt but probably not impossible.

GT6ixer

Hey Roger I have the same situation on my '84. What would an OEM unit run?

Thanks!

ROG100

Hi Nate,
For your car $214.95.
Best,
Roger

GT6ixer

Thanks Roger. Order coming you way soon.

GlenL

I'm not the only person to get these freed up and working.

Pour in some penetrating oil and apply 12V alternating forewards and backwards. It may start to twitch and then turn. Don't run it dry very much. It'll get hot and grind itself up.

If it starts to turn, attach hoses to pump gas between tanks, or around-and -around.

Yes, I'm running a "fixed" pump now.

The way it's made, opening it up isn't really an option. Someone, somewhere has done it, I'll wager, but the crimped top is a challenge.

jcorenman

Opening it up is easy, and once opened finding the problem is also pretty easy. It is either burned/used brushes or some bit of crap jammed into the pump rollers.

The problem is, having found the problem, getting it back together is pretty much impossible. Which means buying a new pump with the satisfaction of knowing why the old one died. (Which of course is mostly useless).

Struan, if your can has an in-tank pump then the most likely problem is the small coupling hose that connects the in-tank pump to the fitting. It tends to split, with age and whatever they put in fuel these days, and allows crap to be sucked into the main pump.

struan

Hi again,
Thanks for your comments.
Roger, it is a 1987, S4.
I didn't realise there were different pumps used as all 4 of my 928's have had the same Bosch pump.
This is the "no keys" car I rescued from a field. It had been sitting for at least 4 years possibly longer.
I tried the "this way, then that way" method. I also drilled a hole in the end of the shaft and put a screw in the hole to get a grip and tried freeing it that way. Wouldn't move.
Out of curiosity I opened it up. Easy job. Found it glued solid with a kind of yellowish varnish looking stuff. Once that was all cleaned off, the pump is running again, just like new.
The tricky, (mission almost impossible) will be to reseal it.

Imo000

I've tried putting one back together, didn't work out.

James Bailey

It is a bit like opening a can of beans......then trying to reseal the empty can....except for the electrical bits inside and fuel residue The "rebuilt" ones I have seen have had a bunch of JB weld looking stuff gooped all over the end !

karl ruiter

Here is a minority view: I have been happy with Walbro pumps in my 928. $100, american made, out perform the spec in he manual, and never had one fail. If Roger can set you up with the proper pump for $200, that is the way to go, but if you are looking at $400, this might be something to consider. The only issue I have had since using them was on my '79. It had old wiring and relays so I was dropping about 2V before getting to the pump. The alternator on my '79 does not charge at idle so the voltage at the pump would drop to about 10V at idle and the output pressure would drop. This resulted in a hesitation coming off idle.