deven07

Hiyas,

I've been having a problem over the last week with my '71 911T Targa with 2.2L and Zenith carbs that has gotten progressively worse, wondering if anyone can give me any suggestions on my next course of action. Shes my only ride, anything ideas you might have would be a great help please!

I'm having a hard time starting it up, I have to hold the gas to the floor, and crank it for a long time before the engine will fire much less stay started, the way I can describe it best is that it acts like bad gas (as of now since it first started I have 3 or 4 tanks full from various vendors, problem persists) or water in the tank or something (tried heet, didnt seem to do much good).

After a long time cranking over, it will eventually start, then run at a rough idle only with accelerator pedal to the floor, sometimes bogging out and stalling again, but eventually seeming to get past this hesitation and allowing me to get some RPM's, and im able to get moving if I dont let the RPM's go too low. Unfortunately, now every time I come to a stop, it will stall if I let the idle go too low (say during a turn from a stoplight, etc.), and it is a HUGE pain to get started again, and usually entails LOTS of cranking and usually eventually getting a jump start from someone elses strong battery to do it.

One thing I did have to do not too long ago because there was no other stations around was to put some gas with 10% ethonol in it (Im in Iowa, they love the ethonol here), not sure if this could be part but I thought I'd throw it in the mix...

I bet there are a thousand things it could be, and there are various issues i think that might contribute, ie the gas, low oil pressure (plenty of leakage), and id guess some time (only had the car two summers and i havent felt the need untill now) since new plugs and a tune up to name just a few....but those are things that have been with me since the start and didn't seem to effect performance for the last year and a half...could I be looking at a fuel pump issue? Once I can get enough gas to the engine she goes ok though, its just when I come to a stop that it stalls...I gotta believe that tank is not very clean, could it be a bad fuel filter? Anywhere you can suggest I start on my own while I save my pennies for the big repair bill? Thanks so much for your help!

Regards,

Jamie
-------
1971 911T Targa

wwest

You have a stuck float (or some such) in one of the carburators. The car won't start because it's flooded and then it won't run very well without first burning off the liquid fuel pooled within the intake system.

deven07

Thanks alot for your reply wwest...any tips on unsticking that float? Will the Haynes Weber /SU/Zenith Carb Manual help? As you can most likely surmize Im not extremely mechanical...Im not really sure what I am looking for, a flashlight and mirror aimed down the throat dont tell me much...but at this point I am almost ready to try anything I can on my own due to lack of $$$ at the moment.

So far I have removed engine and tranny, had tranny rebuilt, put it back, replaced spring arm bushings...thats about it with very good success...where does the carb rebuild fall in Wayne R. Dempsey's difficulty rating? I'd check my copy of "101 projects..." but the pages are fuzed together (along with my haynes manual, new copies are on their way) due to rear pan rain leakage from the targa top that I havent addressed yet either...

Pelican sells Zenith rebuild kits...run $100 for a pair, just the sound of it kinda scares me...would I be better off just letting it it sit untill I can affort to have someone else fix it?

mo_gearhead

I would agree with wwest that a stuck float may be the problem. It sounds as if your fuel system and carbs. need to be rebuilt/cleaned. Having to keep the accelerator floored sounds as if the carbs. are indeed flooding the engine. This, in turn, heavily "wets" the spark plugs, making them hard to fire, complicating the running problem. Flooding and the burning of too much fuel usually will produce dark exhaust smoke?

If you haven't had the car tuned in two years or longer, I would suggest that be done. (plugs, timing, valves adjust, etc.) Unless you have experience rebuilding carburetors, you should probably seek the assistance of someone experienced in that area.

deven07

Thanks for the reply Mo, I've been told to tap on the float bowl that might losen it up...would carb cleaner sprayed down the throat help? I might have a line on a P Car mechanic to help me...not totally solid though, I'd like to try whatever I can in the mean time...

mo_gearhead

Spraying carb. cleaner down the throat will not help a stuck float, you have to get the cleaner inside the fuel bowl. However I have my doubts it will help.. when a float sticks/hangs up, it usually needs attention that carb. cleaners will not address.

But it's cheap and worth a try I guess. You can add fuel cleaners into the gas tank, or spray or pour them down the carb. "vent tubes"... this gets it into the carb. fuel bowls... right at the source if you will. I am not that familiar with Zenith carbs, but with the air cleaners off, look for the small vertical tubes that "vent" the carb. bowls to the atmosphere. Pouring full strength carb. cleaner down these may help you.

Good luck.

Juan

Stuck = NO!

"Sunk" = yes.

Generally carburator floats fail in only two ways.

"Stuck", closed because the rubber "stopper" molds to the inlet orifice over time and then you get NO fuel. In this case "tapping" will often help temporarily.

Or it partially "sinks" due to fuel leaking into the inside of the float and now you get continuous fuel "overflow.

deven07

Thanks for the replies yall...Juan is this at all fixable without taking the carb apart? They look really easy to take off the engine, but anything further I dont think I have the guts to try on my own...a friend who used to have old vw beetles said he used to soak his carbs in mineral spirits to clean them...is this hogwash or a possible step i can take before rebuild, which I just dont have the $$$ for right now...

wwest

Take the carb apart.

What's to lose??

deven07

RAWRRR wwest! Hehe I went ahead and took em off...they dont look so scary after all...they are HELLA dirty! I can hear what I think are the floats turn up and down when I flip each carb over and back...I took off the top of the throats (black, not supposed to be), the housing that connects to the air cleaner cover(black, supposed to be), all the rubber that I can get to, gasket between air cleaner cover connector housing, everything I could remove that looks like it wouldnt like to swim...seems like they could now stand a nice bath! They were so easy to get off, Im anticipating just as easy to put back on...what do you guys think about me just soaking them really well, cleaning what I can clean without dissasembling any furtherand slapping them back on just to give it a try before I look into cost of rebuild or ordering rebuild kits (which i cant spend on anyway atm)?

mo_gearhead

Although I have never used "mineral spirits" to clean a carb, I can't imagine that such a solvent would be good for the gaskets, rubber seats, o-rings, etc. and may in fact compound your problems...

but, if you are resolved to "soak" them, use a tub of gasoline (cautiously, fumes very dangerous and fire hazard!). But I think you are just postponing the inevitable, they need to be disassembled to do the job right.