largecar379

if you are going this far, replacing both the interior and exterior pumps, I suggest you replace them both with one of Barry Grant's pumps---either the Mighty Sumo or the King Sumo. Both of these pumps are plenty big enough (especially the King) to fuel any 928 engine, they are modern pumps, and you'll only need one instead of two......available at Jeg's or Summit Racing online.






--Russ

Jadz928

Alright, this in-tank fuel pump has me curious. What MY's had one? I have this intermittant BUZZ coming from the rear. Replaced fuel filter only and have no record of fuel pump replacement.

Cheburator

Andrew,

Thanks for the great write-up. I have a question for everyone on the list though - my 1990MY GT suffers from fuel starvation on track with less than 20ltrs of fuel in the tank. A quick search here leads me to believe that my in-tank pump has failed. The external is a new (10k) Bosch unit.

Can I get rid of the failed internal pump and run the car on the external one? if the answer is yes, what part do I need to substitute the internal pump? If no, where can I get a new internal pump?

Many thanks in advance,

Alex

AO

Alex-

In hindsight, I should have deleted the internal pump. You can replace it with a strainer instead.

P/N: 928.201.081.04 ~$50

Rob Edwards

Now ya tell me.....


FWIW, it turns out Enco carries the Oetiker clamps, cheap:

http://www.use-enco.com/CGI/INSRIT?P...&PARTPG=INLMK3

Rob Edwards

I pulled the internal fuel pump from the GTS to find that its hose was split too. Greg has the proper Goodyear/Goodridge 1/2" ID fuel-resistant hose, and recommended just squeezing open the Oetiker clamps, pulling out the split hose, and reinstalling/re-crimping them.

The factory piece of hose is 28.5 mm long, give or take. I got a bunch of the hose from him, so I'm good for 100 years, unless I buy more 928's.

ROG100

Rob,
I would be very interested in the spec of the hose. I have been looking without a result for fuel resistant hose of the right size. Plenty where the inside core is resistant but not the exterior. Resistant for prolonged immersion that is.
Roger

ROG100

I have the 044 pump for $185 if any one is interested.

Rob Edwards

Hey Roger-

I didn't get a long enough segment of hose for the printing on it to be informative about what it is. My guess is that Greg knows , shoot him a PM.

ROG100

will do

jpitman2

Unless you are in hot climes and push your car, I believe the internal pump is redundant for most people. My 83 S K-jet (needs fuel at 75psi) has always run fine on a single external pump, even at 120F, and with an S4 pump instead of the spec unit for K-jet.
jp 83 Euro S AT 52k

88porsche928

heres a tip for thoose of you who had trouble re installing the two bolts for the strap, go to home depot and they have really long bolts the same diameter by the ones that the threads go all the way down. i had difficulty with the two straps, the two longer bolts helped me out alot. you can replace the orginial ones or just tighten down the long ones all the way then swap them out with the orginals one at a time.

Lizard928

Roger,

could you not get straight teflon hose and use that instead?

Chuck Schreiber

Checking the internal pump is a good idea on any model that had it.
Both my 79 and GTS looked the same as Andrew's when I removed them.

Replacing the internal and external pump on the GTS cured most of my pinging problems
The 3 prong plugs took care of the rest.

Tom in Austin

I replaced my internal pump last summer and the hose connection was cracked about half-way around. I found the straps to be a real PITA ... I skipped loosening the bolt in front (no 20" extension, etc.) and just carefully bent the thing down just enough to reach in and remove the pump.

Well, that was too much bending and the &*(&#)*&$*# thing wouldn't go back up into place. Ended up using my floor jack to force it up enough to start the bolts with some half-inch spacers to keep from squashing the tank too much.

The other thing I encountered was the forward edge of the pump body is very, very close to the diameter of the tank opening ... like no more than a mm of clearance. The pump body on my new one was not perfectly round, there were two very slight crimp areas that made it just not round enough that it wouldn't go in. It took several careful squeezes with my pliers to flatten those spots down enough for the pump to fit into the opening.

As someone said above, I was very careful not to overtighten the pump since the threaded insert within the tank could break loose and then you'd be totally knackered.

BTW, I did buy a 36 MM socket and it came in real handy. Only way I could see to use any other type wrench would be to remove the strap thing. In the interest of spring cleaning, I'll be glad to pass it along for $20 to someone who's ready to go tackle this job, just give me a PM.

Also, I have the old pump if any one would like to have it for cost of shipping ... if you can replace the hose section and get some use out of it, you're welcome to have it.