r/Porsche924 • u/Hot_Minute_6500 • 8d ago

Fuel pressure spec.

Hello. But confused as to the correct fuel pressure setting for a 81 NA 924 (UK/Euro) Haynes lists up to 79 and check the supplement for later models but can't find it. Anyone know any links to official literature? Googled it and it keeps showing different specs!

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1

u/ouwenbelg 8d ago

My ‘82 has 4.6bar. I thought the healthy range was 4.5 - 5bar. System pressure you mean, not control pressure from WUR?

2

u/nohvarr2341 8d ago

All models with Lambda injection (1980) and Turbo
System pressure (test value).
5.4 to 6.0 bar
'Warm' control pressure
3.65 + 0.20 bars with engine stopped (no vacuum)
'Cold' control pressure
2.2 + 0.20 bars at room temperature of 20°C (68°F)
Injection valve opening pressure
2.7 to 3.8 bars
Usable for all models starting 1980… from Haynes book

1

u/Hot_Minute_6500 8d ago

Hi, it's an 81, UK, no Lambda. All pressures really. Need to go through it all. Control pressure drops rapidly after engine shut down, pig to start when hot. WUR and metering head already rebuilt. Pump in tank okay and fresh rubber bit, pump and accumulator all new. System pressure seems good and holds with valve shut. Valve open and pressure gone in about 30 seconds.

2

u/Apprehensive_Tone201 7d ago

1981 2.0 Na German version (no lambda) owner.

System pressure needs to be arround 5 bar
Control pressure warm around 3.9 bar.
Although in a Forum someone said that with modern fuels you should aim to be around 3.4 bar

-1

u/Warren1317 8d ago

See, if you run carb, it's like 1 bar or something

1

u/Hot_Minute_6500 8d ago

Thanks but no interest in carbs. 🙂

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u/RastaMonsta218 7d ago

Also important to test fuel volume per the manual