924Board.org

[stexch]

My mechanic says the '78 924 na runs great when pouring the gas in by hand. However, when it's hooked up to the fuel line, it will start, then dies. He thinks it might be the fuel pump. Mid America Motor Works (formerly Tweeks) wants $190 for a fuel pump. On my other vehicles, I've installed a generic electric fuel pump that is cheap and works great (but these were carbureted). Will a generic pump work on my 924? If so, what is the PSI that I need to run? If not, does anyone have a cheaper source? Pelican Parts didn't list one.

[CMXXXI]

"pouring the gas in by hand" ??!! I suspect that a full diagnosis wasn't done on your fuel system. I'd start with some basics before jumping in on a fuel pump. Like, if the pump is jumpered, does it run? Do you get fuel at the injectors with the jumpered pump? Is the filter clogged? And the list can go on...

The fuel system requirements on these cars are much more demanding than those with carbs. The system pressure is supposed to be maintained at somewhere around 90psi, with a delivery rate (measured at the fuel distributor) of a little over a liter in 30 seconds. I don't think that pumps intended for most EFI systems and carb setups will come close to these figures.

Yes, the pumps are pricey, but a bit less expensive alternative is one made by Pierburg. Do an archive search and it'll turn up some recent threads. As for sources...well, you're going to have to do your "consumer shopping" to find who has got them, and at what price. Again, the archives should provide a wealth of on-line sources you can check out. Used pumps are always a gamble, though at cut-rate prices compared to new. If you are willing to take the chance, I suspect that some Board members who are parting out cars might be able to help.
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'79 Eurospec 931

[Roger]

I would first try jumping the fuel pump relay. Then try starting the car. If it starts replace the relay. If it does not start do fuel supply test its in the Haynes. Also perform the fuel pump electrical tests. I can email them to you if you need. CIS is very tricky and it requires the proper fuel pressures. I would not recomend a generic fuel pump.
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1981 924 NA

Some people are like Slinkies. Not really good for anything, but you
still can't help but smile when you see one tumble down the stairs.

[welder]

Do yourself a major favor and buy the book " How To Tune and Modify Bosch Fuel Injection" by Ben Watson. This book will explain and make clear everything you ever wanted to know about CIS. It's written so anyone can understand and trouble shoot your 924. Good Luck
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I have a 78 n\a currently under restoration.