1983 SC Hot Start Problem
 

I've got another problem with my "new" 1983 911 SC. Starts cold fine. (sputters a little, but gets up to speed). If I drive the car up to temp and shut it off, it takes at least 2 minutes to start. I smell burned exhaust, but it doesn't even pop. I could run the battery OUT by turning the key. Eventually (with a little gas) it sputters to life, and then runs fine. Here's what I've done. New Fuel Pump, Fuel Filter, Air Filter, Accumulator, 6 plugs, dist cap and rotor. New injector "O" rings, and two new injectors. NOTHING WORKS! Help?

mixture could be way off.

CSV could be on when trying to start. would not think it is on all the time because it would run very rich, but check it anyway.

check valve. depending on how long it is off before you try to start it again. if you turn it off, then try to start it, not like likely the check valve. if it is 30 minutes or so, the check valve could be bad.

on the lesser likely side, due to it would effect driving, but you did not say how it drives, the plunger could be not dropping all the way down when you shut it off, making fuel dump into the engine.

Drop the $120 for a CIS pressure tester. Pelican Parts - Product Information: TOL-TA33865

You probably have a routine residual pressure leak - the leak causes a fall in residual fuel pressure in the lines to fall off when you shut off the car. How did it run before all the fuel system parts were installed? If it started when warm go back to all the parts replaced and check the connections.

Also, did you do the parts install or did a shop?

How much do you know about CIS? It's ok if you don't know squat cause none of us did either at one time. We can point you to some good info to read.

When you say "starts with a little gas" do you mean depressing the accelerator? I remember having to mash the pedal to the floor for about three start attempts (after ten without) to finally get a little cough from the engine and then it would finally catch - but really barely turning over, eventually it cleared out and ran great. A little embarrassing in the work parking lot. :-)

When it is running, and/or when it starts up, the exhaust does have a strong burned fuel smell, enough to make your eyes water.

I put in all of the parts myself... am new to CIS, so I'll grab the pressure tester... your advice totally makes sense as yes, I step on the accelerator to make the car sputter to life after 4 or 5 start attempts.

Thank you guys for your help... been a Porsche fan since age 6, never had one til now!

Oh, also the car runs really HOT. Almost to the red when warmed up... and when it is that temp, If I give it a lot of gas, it has that octane knock... but I only put premium gas in it... Related?

Tune up, fuel pressure check, and possible fuel accumulator failure.

your timing could be messed up. stuck advance, or not set properly.

you should not runit that hot. find out what is going on. you could have a rats nest in the engine blocking air to the fins and cooler. you could have a stuck internal Tstat.

check fuel pressures be fore making any mixture adjustments.

Timing sounds way off!

And I agree that it could be the fuel accumulator, thats what it was on mine!

First, Do NOT push this engine with much load if you hear knock!

From your description of hot operating temps you could have a nice size air leak that causing you to run lean.

You should never hear audible engine knock.

I owned a 75 911 that knocked like you described and it was not very long before I had a hole in a cylinder right at the edge where it meets the head!

sounds like the dizzy is stuck advanced.

Thank You will check all of the above... much appreciated.