80 SC Start Problem

[subseamark]

My car was running fine until I let it sit for a couple months while I did some interior work. When I tried to start it, it would turn over a couple seconds and then die. I purchased fuel gauges and found the WUR control and systems pressures read the same around 70 psi. At that point I leaned my mixture and was able to start and keep running as long as my foot was on the accelerator. However, when I let off the gas the car died. I subsequently had the WUR rebuilt and the control pressure and system pressures are now reading correctly, but car has same problem. It will run maybe a couple seconds before stalling unless I put my foot on the accelerator to keep running.

Any thoughts? I've researched CIS on this forum but haven't found anything exactly like I'm experiencing.

Another question. With the mixture and idle adjustments I've done, unsure now exactly where my settings are. Is there a rule of thumb for starting position for the idle and air/fuel mixture screws. Something along the lines of screw all the way in and then back off one or two turns to begin?

Any help appreciated. Thanks.

[timmy2]

It is posted in this excellent thread.
CIS Troubleshooting for Dummies

[subseamark]

I'm following up on my previous post and what I found. Somewhat embarrassingly this took me too long to figure out. The issue ended up being a broken connection at the breather hose on the backside of the intake air boot. I chased this issue for weeks troubleshooting the WUR, fuel pump, fuel filter, and cleaning the fuel lines. I found the broken connection when I was removing the boot to check the air sensor plate rest position. The connection is difficult to see or notice on the very backside of the boot.

I spent too much time early on focusing on the fuel side and discounted the air side. The rubber on these old Porsche getting brittle.

[subseamark]

By the way, car started right up when I replaced the boot!

[mikedsilva]

Originally Posted by subseamark

By the way, car started right up when I replaced the boot!

Nice work. Glad you found it eventually. It's a good feeling when you fix it!