OK to replace early injection pump with late inline style?

Will98D · 07-24-2005, 05:56 PM

'74 914 1.8: Injection pump crapped out (need to keep tapping it to get it to go). The later inline style seems a lot more available and is a lot less expensive. Has anyone installed one of those in the rear of the car to replace the other type?? I assume the inlet and outlet get used (obviously) and where the return line gets teed into the old style you would just get rid of the T.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Yes, you get rid of the T (it's a Y actually, but no big deal). You will, however, have to do some Adaptor Magic (TM) to get the hoses to hook up correctly; I believe the later pump has an 11mm or 13mm inlet versus the 7mm inlet of the earlier pump.

--DD

Will98D · 07-25-2005, 06:02 AM

Cool, thanks Dave. I may go that route if something I'm working on with the original one doesn't pan out. Will

Tidybuoy · 07-25-2005, 11:39 AM

I replaced mine with a later 75/76 pump. I moved everything to the front at the same time and it was pretty simple to do. I mounted the fuel pump under the gas tank just like the 75/76 setup. If you can find a 75/76 donor, you can take the fuel pump mount brackets and the little access cover - if you can't get these parts, it can still be installed with some creativity.

The only issue is at the rear....the lines coming out of the tunnel (one of them) has to be converted down to match up with the fuel rail lines. I did this with a plastic reducer that I got at an auto parts store. Everything has been working smoothly for 5 years.

Vern

Will98D · 08-04-2005, 03:27 PM

Got the pump, and I also bought the filter that goes with the later year pump. The filter has a ~6mm inlet but about a 10mm outlet, so it also acts as the adapter for the fact that the new pump has a bigger inlet. I'll install this weekend and get back on the road. wd

Tidybuoy · 08-04-2005, 03:32 PM

Just remember that the front is the easy part. You still have to reduce the line connecting the tube exitint the tunnel (at the rear of the car) to the fuel rail line. I have no idea why Porsche did it this way but there's probably a really, really dumb answer.

Vern

Will98D · 08-05-2005, 02:14 AM

I'm using the new style pump but mounting it in the rear of the car, so I don't anticipate this problem. The fuel line coming out of the tunnel looks to be the same diameter as the inlet to the filter, and the outlet of the new pump looks to be the same diameter as the line going to the engine. I'll know for sure by tomorrow, thanks for the heads up.

Will98D · 08-09-2005, 02:39 PM

New pump works like a charm. Never knew they weren't supposed to whine all the time.