WarBound

Well...just got the 80 coupe couple weeks back. Idles for crud and have checked egr and hoses bla bla. Am sending the carb to lars anyway...soon as I at least drive a lil bit anyway for thrill sake:) Anyway, tonite I went and got an alternator, diff prob, I came home and parked in the garage. Half hour later I go check on my baby under the hood and here gurgling/bubbling from the carb. Could this be related to my rough idle and hestitation prob???

Just curious...Like I said, Lars is getting it soon since I have read nothing but good things about him from you great folks!

Thanks and ty for a nice place to hang out:)

WarBound

-bump- and testing my sig also:)

WarBound

Sigh...nobody can help on this one I guess:(

Ron 75 L48

Welcome to the forum! It sounds like you certainly have an issue with the carb. Is it stock or after market?

Nice looking ride! :D

WarBound

It appears to be a stock quadrajet, elect choke model. I bought the car few weeks back and found a receipt, in the glovebox, for $400 to install a rebuilt quadrajet. It was dated June 2002. So I figure it is original but may not be the exact one from the factory. The car runs real rough at idle. Today is my birthday and I got a vacuum gauge from my wife (plus multi meter and torque wrench) so I'll check the vauccum soon. I already visually checked egr and all hoses they look good. I have my hands full...last week one new front left caliper, one new master cylinder and last night one new alternator. I have many leaks and will need to prioritize for those..rear main next winter and radiator soon. Also, my ac and power steering don't work. Rest of the car except for rattles and squeeks and some rust here and there on bird lol, will have to wiat.

This carb gurlgle has me puzzled...but, I'm sending it to lars as soon as I can get at least a lil miles for enjoyment out of it first.

Anybody ever have a carb gurgle 30 minutes after driving? I could here what sounded like bubbling...engine did not overheat either...real weird!

Thanks for replying to my first post...I was starting to think maybe the forum was clickish and I might not fit in cause of being new:(

Btw...I love that shade of red on your stingray!


[Modified by WarBound, 8:27 PM 4/1/2004]


[Modified by WarBound, 8:28 PM 4/1/2004]

Eddie 70

Rich welcome to the forum. Nice looking vette. I love that body style. I don't know about the gurgling carb though. Maybe gas boiling in the intake????

Boofers

Your problem could be a condition called percolation aka hot soak. Besides the gurgling sound some additional symptoms of this may include:
- You have to crank the engine a long time to get her started when she is hot.
- You see fuel trickling down the inside walls of the carb, making your throttle plates wet or even have fuel pooling under the carb inside your intake manifold.

Basically what happens here is that heat stored in the engine block and exhaust manifolds is radiated into the fuel pump, fuel lines and carb. This causes the fuel in these parts to boil, pressurize, and the vapour bubbles push liquid fuel into the carb venturis. Rochester designed Quadrajets so that most of the time vapor bubbles will burst before they push fuel out.

In extreme cases fuel trickles down inside of cylinders with open intake valves. This will wash oil off the cylinder walls and piston rings, effectively shortening your engine life!!!

Another problem caused by high temps is vapor lock. This could explain your poor idle problems. What happens here is that fuel in the pump is so hot that instead of just liquid fuel being supplied to the carb a mixture of liquid fuel and vapor fuel are supplied to the carb. This makes your carb 'starve' for fuel, leaning out your air/fuel mixture, causing poor engine performance. A lean running engine in turn will run hotter...

If your engine is suffering from these conditions sending your carb to Lars is a very good idea. You need to get that thing set up properly. I believe your car was originally equipped with a charcoal vacuum canister. Make sure it is hooked up properly, this will help ensure fuel line pressure does not build up.

Make sure you have a proper gasket between your carb and your intake manifold, this will reduce heat transferring from the manifold into the carb.

Make sure cooling system is working properly, no worn out fan clutch, etc. You could also try to re-route your fuel lines or add heat shields.

Hopefully your problem is simple and easily resolved! Let us know. :cheers:

lars

Fuel boiling in the carb after shutdown is becoming a much more common problem with the poor quality fuels on the market in many areas. The ethanol additives in the fuel lower the fuel's boiling point and increase vapor pressure. Many refineries are still supplying "winter blend" fuels which makes this problem even worse. Unfortunately, a carb rebuild will not do anything to solve this problem for you - it's a fuel problem in your area. Try filling up with a different major brand gas to see if it changes the symptoms.

DJ Dep

Or you could switch to straight alcohol like I'm doing. Then you'll be running ICE COLD and never have to worry about boilin'. Plus you can run outrageous compression ratios. Hard part is finding a gas station that sells straight methanol :lol:

Dep
P.S. Try Shell or BP premium gas. Or if you can locate Sunoco, their best gas.

Veet 66

I have the same problem on my 66. When I first start it the car runs ok. Once it gets to operating temp. 185 degress it runs like s---. Idles rough, when I floor it sound like it misses or running on 4 cylinders. I have installed a heat shield gasket under the carb. (edelbrock) Installed heat boots on by fuel line to the fuel pump and frm the fuel pump to the carb. I took it in to the shop because I thought it was a timing problem. They checked it out and said it was what others have said on vapor and gas.
Lars is correct. the gas SU---. What they said that could help a little until the summer gas is out is to run 50/50 racing gas. I added 5 gal. of racing gas but I can't tell the difference yet. I haven't driven it enough. They also said if the winter gas is sitting in your tank more than 6 weeks it will be worse.
Same s--- different day.

:mad

stingraymaniac

:iagree: :iagree: