After a pause in working on my XJ S2 I resumed work. The car starts OK, with either of both tanks. As I crank, it takes some time to get fuel to the carbs and then it runs. Then I obviously release the key from ‘start’ to ‘run’, and the engine runs for 30 to 40 seconds and stops. It seems to me that the fuel has run out, because when I crank to start again, it takes time again to feed fueol and start. Also: I did a test disconnecting the fuel line and feeding fuel to the carbs from an external container; and in that case the engine keeps running.
I have been unable so far to identify what the electrical condition is that causes this stop feeding the pumps.
- Both LH and RH pumps work in ‘start’ mode, and both pumps stop feeding as the key goes to ‘run’.
- when feeding fuel in a way that doesn’t involve the car’s pumps, it keeps running. (the earlier problem with the resistor near the coil has been corrected after kind input froim this forum)
- The ‘accident gravity switch’ is not in cause: I bridged that cable and the problem is still there.
- it doesn’t seem to be related to the oil pressure detection: I grounded that wire to make sure.
Could it be the key-contact itself? But shouldn’t then also the ignition stop working?
Are there any other conditions that are being checked in ‘run’ and not yet in ‘start’?
The only condition I can imagine the car checks in ‘run’ but not yet in ‘start’ would be oil pressure. Could I have done my check wrongly?
As always, your experience and insight is very welcome.
Manyt thanks in advance to whomever may take time to chip in.