924Board.org

[agfisher]

Hey All,

I have a strange issue with my K-Jet system. It’s a 1977 924 that I have been trying to get running for years but life has been getting in the way. The work I have performed is as follows:

- Dropped fuel tank and had it boiled, sealed, and repainted.
- Replaced Accumulators with used (but in good condition) units.
- Replaced the fuel pump.
- Flushed all fuel lines from back of car to front.
- Replaced the fuel filter.
- Removed and rebuilt the fuel distributor since it was completely seized with varnish. It came part fine and internal components (not counting o-rings, etc.) where replaced. The unit is not leaking under pressure. (I think this maybe where the problem is).
- Removed and cleaned the WUR.
- Tested and checked the CSV.
- Pulled and cleaned the fuel injectors. Tested opening pressure and spray pattern.
- Flushed all fuel lines under the hood.

So here’s what I have done so far:

- Hooked up a pressure test between the FD and WUR. I get a 30psi control pressure (a little high but it started at 65!) and a 67psi system pressure.
- Hooked injectors to my compressor at 55psi and they opened without issue (they opened at lower pressures too).
- Performed a flow test from fuel pump out of fuel filter and got over 750cc in 30 sec.
- CSV is spraying fine.
- With the fuel pump on I crack the bolts on the FD for the injector lines and fuel comes out when the air metering plate is pushed up.

Now here’s what I’m seeing. No matter what I do, the injectors will not spray (all 4 of them!). Pump is running (I can hear the fuel moving through the system) and the metering plate is up but the injectors just don’t spray. I mean it’s has to be a pressure issue but I’m not sure where or how. I have a few ideas to test today (Flow rate going to the WUR is one. Also going to crack a banjo on one injector the make sure fuel is getting all the way to the injector) but I’m looking for any other ideas.

Has anyone else seen this? Any ideas?

Thanks
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1977 924 N/A Martini Edition

[agfisher]

Figured it out and thought I would post the solution for future reference.

Drum roll please....the damn fuel distributor plunger was in upside down! SMDH. That would do it!
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1977 924 N/A Martini Edition

[Fasteddie313]

Wow lol
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80 Turbo - Slightly Modified

[Beartooth]

Darn, and I went through the trouble to write up a response, only to see this! I actually guessed it was the sleeve the plunger rides in being clocked wrong, but the plunger is a much easier fix! I'm in a similar position with an '80 931, except I'm still piecing it back together after dealing with similar issues from neglect; I haven't tried to start it yet. Nasty old gas really makes a mess of things, but surprisingly, the diaphragms and o-rings in the system were all still pliable. Hopefully it's all good enough to get it running at least. If I can't get fuel at the injectors, I guess I know what to check first!
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1980 931 diamond in the rough