restarting the porsche... question

brents42gpw · 04-15-2009, 08:18 PM

I can go out and start the porsche no problems. if I let it run for like 20 or 30 seconds and it dies. it will simplly not restart. no matter how long I turn the key over. but if I let it just sit for an hour or what ever. i can go out and it will start right up. it is a 74 with no carbs. come to find out. so basically when I want to take it for a ride. I need to let it warm up. because even if I take off and we come to a stop sign. and it dies.. and I am stuck.... other than that I love this porsche. any thoughts? I wonder if the little red light on the dash has anything to do with it. it is red and underneath the blinking e brake light..

brent frank

ossiblue · 04-16-2009, 08:24 AM

Quote:

Originally Posted by brents42gpw

I can go out and start the porsche no problems. if I let it run for like 20 or 30 seconds and it dies. it will simplly not restart. no matter how long I turn the key over. but if I let it just sit for an hour or what ever. i can go out and it will start right up. it is a 74 with no carbs. come to find out. so basically when I want to take it for a ride. I need to let it warm up. because even if I take off and we come to a stop sign. and it dies.. and I am stuck.... other than that I love this porsche. any thoughts? I wonder if the little red light on the dash has anything to do with it. it is red and underneath the blinking e brake light..

brent frank

First a word of caution, "it will simplly not restart. no matter how long I turn the key over. " Keep in mind with a CIS that as you crank the engine, fuel is being pumped into all cylinders at once. Continual cranking for long periods can hydro-lock your engine, at worst, and dilute your oil with gasoline.

Questions: Are you using the hand throttle (pulled to full height) during cold starts? Does the car continue to die at stop signs even after it is warm? Is the light on the dash, or inside one of the gauges? It could be the alternator light, and if so, it could account for your problem as your CDI ignition system may not be getting enough voltage to sustain running. However, answers to the above questions can help narrow down your problem.

kidrock · 04-16-2009, 02:30 PM

The first thing I would do is check to see if it's getting fuel. Pull one of the vacuum lines and spray some carb cleaner into it, then reconnect and start the car. If it starts then dies, you know you have a fuel starvation issue.

Sounds like a dying fuel pump to me, but I'm not familiar with the vagaries of CIS.

brents42gpw · 04-16-2009, 09:16 PM

ok. I took her for a ride tonight an here is what found. from a cold start I pull the hand throttle all the way up. and i don't touch the petal. it will start every time. then as it starts to warm up it will rev really high and I have to lower the hand throttle until it is warm (3 minutes) when i do this the car is fine. although in fear of it dying I will leave the hand throttle up a little when I hit the first set of stop sighns. but it won't die at all and I had a really nice ride
secondly thie light that was on was under the brake light and I think it had the letter G on it? it comes on when I am trying to start. and mabee this is normal. but after the car is started it quickly goes out. when the car is warmed up it will idle perfectly even at stop sighns and the hand throttle is near off.. anyways I took her out on the highway tonight. I have to get used to the tight and precise steering. I am used to my other vehicles that don't turn as tight. I had to really grab the wheel and was a little tensed up just trying not to over steer. it will take some getting used to. but I sure love it... thanks

brent

HarryD · 04-16-2009, 09:30 PM

Brent,

Your car is working as Porshce Intended.

Since your car does not have a choke, the hand throttle performs several functions. When you pull it all the way up, it opens the throttle plate a bit and activates a mcroswitch that is powered fromthe wire to the starter solenoid. When you crank the starter, the other side of the micro switch activates a 7th injector to richen the mixture so your car will start. When you release the key, the 7th injector shuts down. As the car warms up, the Warm up regulator (in hte car) heats up and adjusts the fuel pressure to the uijectors causinghte idle to increase. This is why you need to adjust your hand throttle until the idle stabilizes.

The red light is ahte Genrator light and it is telling you if the alternator is charging your battery (or not). If it is lit, then you are not charging your batttery due to: 1) Broken fan belt; or dead alternator. You should see it illuminate before you start the car and go out once it is running.

brents42gpw · 04-16-2009, 09:36 PM

thanks harry. that does answer alot of questions I had. now if I could just get the car shaking syndrome under control.. intermittent shaking in any gear... I am thinking it is the clutch now. it will stop shaking as I am driving when I depress the clutch petal. oh if I were a porsche mechanic. I am actaully a copy machine tech. I have fixed them for 15 years...

see ya

brent

HarryD · 04-16-2009, 11:11 PM

Brent,

Are you keeping your rpm's above 2,500 at all times when you are moving? Unlike American cars which typically loaf along at 1,500 to 2,500 rpm, these cars are happiest at higher revs and do not like to be lugged.