1979 911 SC Rebuild Starting Problems

[azmaway]

Just changed all the head studs on my 911 SC. Replaced all the usual stuff in the process. Did not do anything to the K Jetronic system, however - Just removed it and replaced it.

Having trouble starting the engine. Engine turns over with the starter and fires during this turnover period. However, as soon as I let go of the key, the engine dies and will not fire on its own. Does this sound like an injection system problem. I have checked as many potential vacuum leaks as possible.

Does anyone know a mechanic who could look at this in the Central Massachusetts area (just North of Worcester City)?

[proporsche]

hi check your two connectors behind the air booth. If you just by chance switch them..
Ivan

these

[Flat6pac]

Changing the connectors shouldn’t have any affect on running.
If they’re backwards the fuel pump will run with the key on.
To run, you need proper timed spark, fuel and compression.
Remove the red relay for the fuel pump on the front board the numbers are on the bottom of the relay
Jumper wire from thirty to eighty seven A. With key on will run the fuel pump.
If it starts, fuel relay is the problem
For spark, check and make sure you’re not one eighty out by removing the # one intake valve cover, set Z one on pulley, intake rocker should rock. If it’s tight, you’re one eighty out.
Another check is having the rotor approach the notch on the distributor rim CCW to make sure the distributor is on the TDC mark and not a cog forward or backwards as one cog is thirty degrees that will make you almost run
Good luck
Bruce

[proporsche]

Hi Bruce..isn`t it true if the safety connector on the sensor is no longer good and connecting to it will actually kill the fuel delivery...????
Ivan

[Flat6pac]

Ivan, I have not seen it happen, not to say it couldn’t, but I told him how to run the pump.
I do believe it in the timing, but it’s not my build so everything has to be looked at.
Bruce

[proporsche]

Of course you checklist is perfect...
The connector on the back we used to disconnect because exactly for this reason back in the 1980`s and clients did not want to replace the bosh plug on the sensor plate...cheap troopers...i have experienced this problem plenty of times....the only bad thing was after the plug was disconnected the pump would run as soon as you put the key on..which i personally did not really like.
So if az...plug is no longer good and he plugged it in ..that is my thinking...but we do not know if it was plugged in before the job or not;-)?

Ivan

[Flat6pac]

If you don’t meter the cold start Injector to the left chain cover thermostat, it’s very easy to get them backwards. You just guess until you turn the key and hear the fuel pump
Bruce