my 356 runs like crap - octane!?

[Atlantic07]

I am frustrated:

I just purchased this 1959 356, 1600 Super and it runs crappy - worse than any vw I drove.

Here is the deal: I looked up in this forum which octane rating to use and understood that 91 was fine.
So I got the 91 (pretty much for the first drive). It runs crappy - no torque! So sad!

What can I do? What do you guys run? Is it possible to make changes to the engine/plugs or whatever to allow for lower octane rating?
And also this stupid valve is leaking when on "AUF" - so I am driving on "RES" the entire time (4 miles only maybe!). I was wondering if it might not get enough gas, because of this valve not working correctly!?

If it is not the gas, what is it then?
I replaced the points (good - no more backfiring downhill!). All cylinders are running!

I don't know what would be better. I hate the idea of having to get high octane gas (it's far and really expensive), but also hate the idea that something is wrong with my toy (in case it is not the gas)

Any input, ideas, feedback and sharing of experience is welcome!

Thx everyone!

[ed martin]

Sounds to me like you probably have a fuel supply issue. If you just purchased the car it more than likely had been sitting for some time in PO garage resulting in sediment (rust) settling in the fuel lines, the fuel cock, and most importantly likely clogging the jets in your carburettors and settling in the accelerator pumps. I would go through the entire system- rebuild/replace the fuel cock, the rubber lines( blow solvent and compressed air through the metal fuel lines), make sure the fuel pump is functioning( possibly rebuild/new diaphragm) and though roughly soak and clean the carburettors.

[id10t]

You'll only need the higher octane if you have a higher compression motor. My stock 65C runs great on the cheapest stuff I can get ...

I'd look at fuel supply, and do a basic tune up. Check valves and timing.

[Les Paul]

Does it run ok full throttle? I've always had a problem with clogged idle jets. I've tried various filters over the years but have a custom short screw driver to take the idle jets out and dislodge debri. These are Webbers so it is pretty easy if you don't drop one. Other symptoms are backfiring, and hesitation unless you are at full throttle.

[Atlantic07]

Good news with the gas! Thank you guys.

It does run better full trottle (freeway), but it does not run well when I push the trottle (taking of in first is a nightmare).

I'll work on it tomorrow and let you know how it went.

Is it hard to work on the (on, off, reserve) valve? I need to fix that leak!

[ed martin]

Is there no longer an edit feature? I mean I've got thoroughly misspelled complements of spell check. Anyhow, it goes without saying to check all of the basics first ( like the fuel filter and basic tune up). As a matter of course though you'll more than likely find out that it is probably carburettor related(like mentioned above, a clogged jet). I use my 58 as a daily driver and I know periodically I have to blow the jets clear to avoid the problems as described.
Other possibilities are float bowl issues- sticking valve, incorrect level, sinking floats etc.

[Les Paul]

I've had my 356 for 16 years 5-6 years as a daily driver. If you have plugged jets you have to blip the throttle several times in first before you take off. It is amazing how small the particles are that plug the jets. The best thing I've found to clean them is a wire from a wire brush. Sometimes out on the highway if you are at full throttle and back off completely they'll clean themselves but not very often.

[ed martin]

You can buy a rebuild kit for the fuel cock. Short of that you may just want to take it apart and clean it. Pay carful attention how it comes apart because reassembly can be tricky. Remember that to remove the collar (the thread portion that attaches to the tank) has REVERSE thread to remove it from the fuel cock. I use liquid teflon on the threads to insure against leakage upon reassembly. The hardest part of working on the fuel cock is draining the gas from the tank. I always disconect the fuel line from the engine end of the car to do that!

[Les Paul]

When I got my 356 I was the 3rd owner. I got it with a box of parts. There were 3 fuel cocks in there. The one in the car was naturally leaking. So I took it out, problem solved.

[mpribanic]

Don't forget to check the fuel filter. I've been battling crud in the tank. As the crud gets pulled to the filter it begins to clog it up. My gas tank is now pulled and getting cleaned out. In the meantime I would buy a glass fuel filter, one that you can see rust in and can be cleaned and put back in. Then I would move to the more complicated area's...

My .02

Mark