Lesson learned. All relays aren't created equal.



http://forums.pelicanparts.com/porsche-911-technical-forum/741033-911sc-frequency-valve-problem.html

Thanks for the.link!

So which is the correct part number from NAPA or should I just order from Pelican?

Good job on following through with the connector. Looks just fine.

Yep, get the right relay.

Your frequency valve is not powered when you lift the sensor. I will double check this when I get to the shop. I will do lift test with and without repay plugged in.

I always thought it was the freq valve but I also read it is not (when lifting)

Bring the old relay in to NAPA. It is a pretty common relay.

Great reference. Thank you.

Bob,

Thank you for being patient with me.

I used the original relay when I lifter the plunger with the ignition key on to listen for the FV buzzing.

Also, I am not sure if the idle changed when I disconnected the O2 sensor since it was running rough and not up operating temperature. I was afraid of running the motor to long for fear of it self-destructing.

I was just emailing my friend about the issue and he also has an 82 SC, Peter Zimmerman's old coupe. A while back he had the same issue I had because of bad gas he filled up from a "no-name" station. It cleared up when it was filled up with new clean fuel. He mentioned the location of the gas station and I think it was the same one I used the day before I started having the problem.

Ugh.

On the upside, even if all this relay stuff was unwarranted, you have a better idea of the system and a new relay will make a Lambda car run a tiny bit better.

I agree.

I will update if it runs better after cleaning the fuel.

I will try with and without relay when I get to shop.

I think the noise is pressure, not freq valve.

With relay I can hear buzzing and screeching. Without, screeching only. It is the freq valve.

I think the freq valve can be put to bed.

If your gas, how you going to handle?

Thanks !

I will siphon some gas out from the bottom of the tank though the fuel sender hole, pour some Techron in and new gas.

Then change the fuel filter.

Do it in the driveway. You never know.

10-4

When I used to live in NY there was a local air-cooled VW mechanic that looked like the crazy biker from Raising Arizona.
I walked into his shop one day and he is in the process of draining a fuel tank with a lit cigar in his mouth :eek:

Luckily nothing happened.

Mom's Dad was an operator at a refinery late 40's through early 70's. Remember him telling me they would wash driveways down with diesel fuel and puff them up. Said diesel vapors would not ignite. Not sure of the time frame. Guessing earlier in his career. :-).

I also remember big fires at the Sunoco and SOHIO refineries in Oregon, OH (Toledo area) were a couple times per year event as a kid. :).

Keep us posted.

I spoke with the owner of a local Porsche shop and he suggested I drain the tank and refill with new fuel.

He suggested only using Shell Premium since they stopped selling ethanol free 93 octane in NC. Highest grade is 91 and from his experience he noticed the ethanol free gas has poor quality now :-(

That hex is 22mm on the bottom of the tank. I have a big cold chisel an the shank fits in there nicely. Big crescent wrench.

Good news, all is well now.

I filled it up with a fresh tank of Shell gas along with a bottle of Techron.

It was still running rough and felt like I was driving a 912.

After about 15 minutes the sputtering stopped and suddenly it took off with full power:D

I drove another 50 miles and all is well now.

Thanks for you help everyone SmileWavy


Lessons learned:

Do not get gas from Marathon gas stations

Do not think to yourself "Wow, this car is running great" unless you want to be slapped by Murphy's law.

Another follow up.

The following morning it was hard to start again and low on power.

After a 2 mile drive it cleared up and ran great.

Next morning started up great and about 10 miles later it was down on power-felt like a 912 and it was difficult to go past 4000 RPM.

Drove about 30 miles thinking it would clear up, nope ran rough and idled at 400 RPM. About 3 hours later went to restart and it would fire up and then die, also noticed the smell of gas - engine flooding:-(

Finally got it running and made it home and decided to have some lunch. After lunch I replaced the 02 relay I received from Pelican and it started up fine and idled like normal.

Next morning it started up fine and went for a drive, felt like it gained about 10 HP:-)

I am wondering if it was the 02 relay all along or the issues with the bad gas killed the 35 year old relay.