924Board.org

[Ondrich]

Hi there,
I was recently changing injectors on my car (1985 euro 924 NA) and to change them I had to unscrew all the banjo bolts from fuel distributor and remove the hoses that lead to the injectors. After fitting the new ones, the car won’t start. Later I discovered, that I don’t have a fuel going to the injectors. The fuel pumps OK to the distributor, the banjo bolts are wet and leak a bit of fuel when removed, but the injectors won’t spray, which quite bugs me. I don’t really know, if there might be air in the system (don’t know if that could happen) or the fault is elsewhere… So if you had dealt with similar issue or you suspect what might be causing the problem, please, let me know!

I also tried to screw back an old injector, but with the same result - no fuel came out. However I may have tried to start the engine with badly installed spark plug wires (probably wrong firing order), the engine turned, but misfired and I heard two snaps from the front left part of engine bay (looking from back to the front of the vehicle), so the question is - Is it possible, that I ruined my fuel distributor??

[gerben1986]

Hi, did you check the airweightplate of the fuel distributor?
I can't imagine that the fuel distributor itself broke down.
_________________
911SC - 1980

[Ondrich]

[Ian89C4]

I had this happen to me when I installed brand new injectors. The new springs inside the injectors were too stiff for my fuel pressure settings.

A simple test you can try is to have all four injectors hooked up and placed into glass jars or cups. From there jump the fuel pump relay (search on the board and you will find a lot of threads on jumping the relay). Once the relay is jumped then turn on the ignition to run and you should hear the fuel pump running and you should also hear fuel flowing through the fuel distributor. Once you hear that press up on the "air plate" and you should have you injectors spraying. If this does not happen you probably need to get a CIS pressure tester and diagnose your fuel system.

I would imagine though that your system is working fine, as it was working before you replaced the injectors, and that the new injectors just need to get that little jump start before they start working normally. Even NOS injectors have been sitting on a shelf for a few years and things may be a little stuck inside.

Hope it works out,

Cheers.
_________________
Ian Edgerly
North Carolina

Current:
1981 924 SCCA/ChampCar Weissach Race Car ("Serenity")
1987 924S ChampCar Endurance Car ("Der Weg")
1980 924 Euro ("Wahala")

[Ondrich]

Ian, thanks for the recommendation, I tried what you described and indeed, all of my injectors were spraying. However when I tried to crank the engine with my injectors out, they did not spray. Could you please give me an advice what to look for next?

Thanks

[Ian89C4]

They won't because there is un-metered air getting into the combustion chamber and into the intake from the open injector holes. With the compression and exhaust phases of the engine pulling the air in through the open injector holes your air plenum plate is probable not even being lifted up.

Try putting the injector back in and try it.

If you still have problem you will need to get a CIS pressure tester to see what is going on with your system.

http://www.amazon.com/CTA-3420-Jetronic-Injection-Pressure/dp/B008FJXA3M

You need to test the cold, hot and system pressures to properly diagnose what is going on, if there are still issues after you put the injectors back in it could be anything from your fuel pump going bad, to a blockage in the fuel filter, to something wrong with the fuel pressure regulator.

But I really think that the system is fine if she was just running before you put the new injectors on.

One more question, have you adjusted the fuel/air mixture screw since you put the new injectors in?

Cheers,

Ian
_________________
Ian Edgerly
North Carolina

Current:
1981 924 SCCA/ChampCar Weissach Race Car ("Serenity")
1987 924S ChampCar Endurance Car ("Der Weg")
1980 924 Euro ("Wahala")

[Ondrich]

No, I was messing with the timing a bit, but I didn't adjust the mixture. Thanks for your help!