87 Targa starts cold but takes 3, 4 sec cranks to start when hot

[al lkosmal]

1987 Porsche 911 Carrera Coupe - Fuel System - Page 3

there is a check valve, attached to the fuel pump, that stops the fuel in the fuel line, from running back into the tank, when the car is shut down. When they fail ....it can take a few tries/seconds for the fuel line to get primed again.

I'm not sure of the 3.2 Carrera, but the CIS cars have a cold start injector that fires fuel into the intake, when the engine is cold, and gets the engine started......but when the engine is warm, the cold start injector does not fire........and if the fuel pump check valve is faulty.....the fuel line is empty and you get the type of warm start condition that you are describing. i.E...much cranking while the fuel pump is priming the line.

regards,
al

[stlrj]

Recently replaced the plugs on my 87 for an intermittent miss and noticed it starts noticeably faster cold and warm, in addition to taking care of the low rpm miss.

Could the solution be that simple?


Cheers,

Joe

[Democreature]

Here is the final outcome. Driving out of my driveway, the car quit and refused to start. The night before it also refused to start, I open the hood and notice that sparks were jumping off the coil to the grounding wire. I replaced the coil wire. Still didn't start. Then I determined that the fuel pump was shot. Earlier in the year I'd purchase a bosch fuel pump anticipating this problem. I replaced the pump and it still didn't start. I read more on this form and discover a possible culprit. The Idle Control Valve. I cleaned it and still no joy. I open it up and removed the armature ( I was going to replace it anyway). I cleaned it and sanded the commuter and the brushes (for lack of a better name). Reassembled it, crossed my fingers. One crank and the engine roars to life!