cold start problem 71T

[super9064]

I have a cold start problem with my 71T, I follow the manual, “Fully depress pedal 2-3 times slightly touch accelerator”, fires right up. It then chugs RPMs drop and dies, I do this 4-5 times then it finally starts and stays, RPMs slowly climb. My car has a hand throttle if I follow the manual from my 69; it states, “Pull hand throttle lever up to stop. Do not move the throttle pedal at any time during the starting procedure” When I start using this technique, again it fires right up, RPMs slowly drop and it dies. If I try to give it some gas, the RPMs drop, its like turning off the ignition if I depress the pedal more than ¼ inch. My current starting technique is to depress the gas pedal 5-6 times, hold to the floor, when it fires pump 8-15 times fast it will then maintain idle. My mechanic did a carb set up when I first purchased the car, said it was way off, also changed fuel lines. I brought it back same problem, now worse, rebuilt accelerator pumps, just as bad or worse. He tells me “starts fine for me, come pick it up” I've had 4 other carbureted Porsches, I have no problems starting any of the others. The car starts with no problem after its warm. Has any one else had this problem?

[boxster03]

I remember an old trick of starting a cold carb engine in the old days. you would fully depress the accl. pedal and hold it for a count of 3 doing 1 thousand 1, 1 thousand 2 etc. then you would "slowly" release it to the top and then depress again but only "half" way down and then turn the ignition key to start. I recall this working on old 60's and 70's cars back in Iowa in the winter. worth a try

[John P]

There is definitely something going on there. My stock '71 T starts with 2-3 pumps of throttle pedal, turn the ignition, feather the throttle once started, and lift the hand throttle to approx. 2000 RPM for 1-2 minutes.

Assuming that you've gone through the engine (valves, timing, etc.), it certainly sounds like accelerator pumps. I believe the owner's manual shows you how to wrap a piece of wire around a small vile, placing it under the nozzle to measure the volume in each barrel. You can then compare them to the factory specs, which I believe are listed in the same manual.

If you slowly get on the gas once the engine is warm, how does it run?

John