Question: Are there 02 Sensors on RoW SCs?
 

Just wondering if my 1978 RoW SC came with 02 sensors..

Thanks,

Jay

Not originally. At least I have not seen any with an O2 sensor around here. But I have been wrong before. Imported to the US they may have put it on along with a cat however.

Edit: Just noticed your location.

No. Most likely it originally came with none, since Porsche didn't use them on ROW 911s in 1978.

Two O2 sensors came much later.

JR

Okay thanks.. I dont think it has one installed since it never set foot in the US. Just wanted to make sure since Im trying to narrow down causes for slight backfire while idling. I've been adjusting both timing and mixture but still cant seem to get rid of it. Trying to change leaks in the valves or the exhaust system..

Anywhere else I should look?

fuel pressures
intake leaks (any false air, not just the intake gaskets)
carbon on the back of the intake valves
cold start injector leaks
injector spray patterns
free sensor plate movement

JR

Will check on those one by one.. Youve been very helpful thanks!

+1 on vacuum leaks.
Do a search on how to trace; I found it easiest with an Acetylene torch (Small nozzle)

Thanks for the tip. I will do that. In the mean time, I am cleaning both fuel filters since they seem to have accumulated some dirt. Forgot to say earlier in the thread that the car sat for over eight months without running in a shop where heavy construction was going on.. So, I'm trying to clean everything up first.

?????Cleaning both fuel filters????
The SC has only one and it cannot be cleaned; it's replaced with a new one.

I'm thinking (hoping?) he meant the outside of the filter. It sounds like the car is a little dusty from sitting in the shop.

Jay, for what it's worth you have one fuel filter, and a fuel accumulator that looks somewhat similar to a filter.

JR

+2 on vaccum leaks.

Check for em.

Sorry for the confusion. i meant the filter attached under the gas tank. Will check on vacuum leaks today.. I also had the gas tank cleaned..

Thanks.

Do you mean the filter screen in the gas tank outlet? Other than that, an SC only had the single filter in the rear of the car.

If you have another filter in the front, somebody has added it to the car.

JR

Hi JR , yes the I meant filter screen. Not familiar with proper terms..thanks..

After you clean the screen in the tank, you'll need to flush out the lines leading to the engine!
Get a fire extinguisher!
Disconnect the line on the acummulator, place the line into a small container, jumper the pump-relay for a few seconds to fill the container.

If you don't know how to jumper, do this:
Disconnect the line on the acummulator, place the line into a small container.
Open the lid on the airbox, emove the air filter, ignition ON, reach into the airbox and gently lift the air sensor plate; the pump should run.
Gas will spill, so, have a fire extinguisher!!
Re-connect the line.
Have fun.

Got it. Actually asked a friend who's done this before to help me out.. And yes thanks for the fire ex reminder!

You guys have been very helpful. Much appreciated.