1979 porsche 928, cis fuel system which means there is fuel all the to the injectors . so if i have a good spark and fuel why dont car stay running. porsche 928.

Asked by STUMPPY47 Jul 24, 2013 at 10:03 AM about the 1979 Porsche 928

Question type: Maintenance & Repair

79 Porsche 928 have cis fuel system..(constant fuel to injectors). if I have spark, fuel and
compression car shot start? well it does as long as I keep giving it starting fluid. pulled a few injectors they are wet, which makes me think they are firing. don't fully understand what causes car not to stay running if all three major components are present. could not enough pressure from the fuel pump cause this problem? just bought a new pump.it wasn't a bosch.

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James answered 11 years ago

fuel pressure should be measured at fuel rail, fuel filter can clog if old, and bad fuel will throw you a curve

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Stephen answered 11 years ago

Are you getting a pulse at the injector(s)? If not, you can have a bad crank sensor or even a bad ECU. Check for pulse with a test light to one of the injector wires or using a long probe to listen for an electronic "click". No noise or no flashing probe light, then that"s your problem. Also check your fuel, it should always be fresh. Plugs will ignite starting fuel but sometimes won't work on old gas, so check your plugs also. Good luck

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