pop valve popping out! help!!!

jinos · 06-22-2005, 06:36 PM

Hey guys. I'm pretty new here and I got an issue with my 911sc.
I just replaced the fuel pump and once in awhile I try to start it and it starts up but makes a sound like it's gonna stall or choke. Then it makes a small pop sound. When I open the airbox, my pop off valve came off. You can see some smoke coming out of the hole. Not alot though. It does this once in ahile. The mechanis said I need to adjust my fuel. What do you guys think? Thanks!!

ras911 · ras911's Garage

Not sure , but seems you need to check the mixture and definitely you need to secure that pop off valve other wise it will keep blowing out . There is a epoxy (either w&b or J&B Weld or something along that line) that is supposed to work well on plastic. Available in your local hardware.

EdT82SC · 06-22-2005, 08:16 PM

My pop off valve popped out. I used JB Weld to put it back in, and I haven't had a problem since. Have your mechanic adjust the mixture. It should only take him a fe minutes.

jinos · 06-22-2005, 08:54 PM

Thanks alot you guys! I'll try that.

Bill Douglas · 06-22-2005, 09:17 PM

And rough up the surface you are going to epoxy with some sandpaper. Expoy has trouble getting a grip on very smooth surfaces.

dandrews64 · 06-22-2005, 10:00 PM

Heed Bill's advice. I had the same problem and scuffed and cleansed with brakleen the surface before re-epoxing. Been 12 months now. (fingers crossed for anti-jinx!!)

jinos · 06-23-2005, 11:32 AM

By any chance do you guys know how I can adjust the mixture myself? Thanks!

William Miller · 06-23-2005, 11:51 AM

Depends on the year and if it's been done before. For earlier cars the adjustment is with a long 3mm alen wrench that goes into the top of the air sensor box between the fuel distributer and the big rubber boot.

Clockwise = richen
Counter clockwise = leaner

This is easy to screw up if you go too far.
Supposed to be done with a gastester. Look up Gunson Gastester for a cheap model.
A few more details with later SC's with lambda control.
Also I have herd, but not seen that the US models are supposed to have a tamper proof plug that needs to be drilled out. The procedures in the manual say to remove the unit which is a lot of work. There must be someone who has an easier way. Most likely it's already gone.
I'm sure someone will fill in more details if you supply more info on your car.
Luck!

jinos · 06-23-2005, 12:00 PM

Thanks a million! I'll try that out. My mechanic told me to richen it. Keep you guys updated.

Argeo · 06-23-2005, 12:40 PM

Just keep track of how many turns. It is nice to be able to go back to square one if necessary.

Paulporsche · 06-23-2005, 01:44 PM

Remember, a little goes a long way. According to previous posts, one complete revolution seems to be somewhere between 8 and 12%! If you are doing this without a gastester, go in 1/32 or 1/16 turn increments.

If the idle starts to fluctuate or if the engine wants to stall when you come off the throttle when coming to a stop, your mixture is too rich. You should back it off 1/32 or 1/16 turn or so from there. If you do this on a hot, humid day, then you should be good. If it gets hotter and more humid later, you may have to lean it a little again.

I don't know where Oaktown is (Oakland?), but if your temps drop in the fall, you may have to richen it back.

jinos · 06-23-2005, 02:54 PM

Thanks. I'll give it a try later after work. Yeah it's oakland. It sounds nicer, don't it? When I say Oakland people tend to say bad stuff.