Car won't start- 1969 911E engine with zenith 40 tins (converted from MFI))

[procan]

So my car won't start. Just FYI, this is my first Porsche, bought it a couple months ago, and I'm a newbie.

The car was getting harder to start for a couple days. I'd turn on the car, press the ignition button, put the gas pedal to the floor, and it would take a few seconds for the engine to fire up, and when it did, it would be really weak at first, you know that bogged down feeling/noise, then after a couple revs it would roar right up.

The day it stopped starting, it did this, but it wasn't roaring up, just kept that bogged down feeling where if I took my foot off the gas it would die. I tried pumping the gas pedal and revving it, but after a few bogged down revs it quit. When I tried to restart the car the starter turns over and over and over, but the engine doesn't start up at all.

I thought maybe I flooded the spark plugs (having carbs and all) so I just changed them out, charged the battery, and tried again. Car still won't start. Still does the same thing where it turns over and over and over but doesn't fire up.

Maybe it's a jetting issue or something, but since this is my first Porsche, I'm pretty new with all this, and need a little bit of direction.

[Joe Bob]

Shoot some ether/quick start into the intakes.....start it. If it coughs are runs a bit, it's you fuel supply. Clogged fuel filter or low pressure.

If it doesn't cough or run, likely a spark issue. Points, CDI or coil.

[procan]

Thanks. I was just at a pca BBQ and got the same advice. I guess if it was a jetting issue then it would still be running, just rough.

[unclebilly]

Your car has carbs. Carbs have accelerator pumps.

Pump the throttle 5 times before you start to crank. You may also want to pump the throttle while cranking. You have no choke with carbs so your throttle is effectively your choke. 1/2 throttle is 1/2 choke. Full throttle is no choke.

[924CarreraGTP]

I usually pump my foot to the floor once, and then push my foot just slightly on the accelerator when I turn the key. Also my 911 with Zeniths pumps into one carb bank at a time when I first turn the key on. So I turn the key on and prime one carb bank, then turn it off and back on to prime the other carb bank. Then then once full throttle to let let some air in and then 1/4 throttle to start. It usually starts right up.
You need to see if the car is firing. If it's not firing it may be the CDI. I've had posts about it on here and Grady is the man to talk to. He told me how to test it. My CDI has actually crashed twice. The second time under a rebuild warranty. Check for spark.

[procan]

Tried the gas pedal pumping thing. Still doesn't fire up. I guess I should use ether/quickstart, but want to get a fire extingusher handy before. Also, my fuel pump in the back is quite loud, and there is gas leaking from a hose->metal tubing connection just before. I'm thinking maybe that fuel pump is clogged, and the back pressure is causing the connection to leak at that weak point where it wasn't leaking before.

[1QuickS]

I guess idle jets or idle circuit (one or more) are clogged. Leaking fuel at the hose won't restrict fuel from filling bowls enough to start.

Even if you use ether to start you still have an issue you need to address; getting it started by blipping the throttle won't fix anything.

[kkinzli]

I had something similar happen on my 69 and it was the points in the distributor. I simply reset the points to a correct gap and have had not had a problem since.

[darrenhall]

I noticed a few responses to your problem. I think you found the problem. you said that your fuel pump is making a lot of noise. That doesnt mean that it isnt functioning properly but it does tell you that it is working hard for something. I would disconnect the fuel line between the carbs and the fuel pump. Make sure that the disconnected line is put into a bucket to collect fuel. Turn the key and go see what kind of fuel flow you have going to the carbs. I suspect you may not have any. Your problem may be a clogged fuel filter , or you may have a clogged line closer to the fuel tank. One thing I would check would be the Fuel pick-up filter in the bottom of the fuel tank. If there is any debris in the fuel tank it will find its way to the filter. But only check this option if the fuel flow is non-existant past the fuel pump. Also, I would install an inline CLEAR VISIBLE fuel filter both before and after the fuel pump. This will help keep the pump healthy but will also give you a visual reference as to wether or not you have fuel flowing in the system.

Good Luck

Darren Hall