Tried to start the Corvette yesterday......

[bobmanx]

Sunday I got a chance to take the Corvette out try to run some gas through it, but it was not to be. It had not been run since Thanksgiving. Sitting in the garage and tried to start it (67-327/350hp stock with AC) and it caught and fired and sort of just died. Tried to restart and it acted like it was firing on a few cylinders and then it stopped firing at all, no backfiring, etc.

Smelled gas and opened the hood to see what was going on and the air cleaner was flooded with gas and there were puddles of gas all around the manifold, both sides, and top of carb was wet. Quickly started mopping up the gas, took the air cleaner outside, turned the garage fans on and was cleaning up the gas, dont need to relocate the garage!.

After cleaning up all the gas I was checking things out and all the hoses looked OK, no cracks in the fuel line, The butterflys were wet and when moving the throttle linkage the accellerator pump seems to work fine, but where or how would all the gas get to the air cleaner. When I opened the hood the gas was dripping out of the lower part of the air cleaner. Is there a way for gas in quantity to exit the top of the carb (3810?) ?

After cleaning up everything I tried to turn it over with the air cleaner off the car to see what gas was coming from where and it would not turn over. I disconnected the battery and decided to play another day as now the wife was complaining of the gas smell from the first attempt and we had plans.

So my questions are many and being new to Corvettes and a convert from imports where do I begin? The car ran great last time it was out (Thanksgiving) and no problems running, idling, heat, etc.

Thanks for any and all information and suggestions, other than sell it. LOL

Bob

 

[Subfixer]

Sounds like the float is stuck open and the gas is coming up the bowl vent tubes into the air cleaner and down the carb throats. It wouldn't run because it was being flooded.

 

[Grizzly]

Sounds like the float is stuck open and the gas is coming up the bowl vent tubes into the air cleaner and down the carb throats. It wouldn't run because it was being flooded.

I agree with Subfixer. THIS IS A REAL DANGEROUS SITUATION!

This is one of the reasons to run them up to operating temp once in a while even if you don't leave the garage. Hopefully everything get softened up and lubed up with gas, lube, and coolant.

Get everything cleared out and charge the battery to full. Pull the coil wire to keep it from starting and crank it to see if the floats are free or if it is still pumping gas out. Then you have to decide what to do.

I actually had this happen on the open road. Had driven 60 miles to a show and on the way back got on it hard and the floats dropped and stayed open. You can imagine how much gas there was in the engine compartment after a run up to 5000 rpm. Took it home on a rollback and installed a 650 Barry Grant when I got home. That worthless Holley will be in the back when they bury me in her. And besides it runs so much better......................

 

[RodsnRides]

Subfixer is on it

I have to agree. There must be sediment or varnish between the needle and seat in the carburetor. You will to remove the float bowl and clean the inlet needle and seat with compressed air. I recommend rechecking the float level as well.

Even being new to the hobby, if you are mechanically inclined, it is not a stretch to clean this part. The only issue you will (probably) encounter is stuck float bowl gaskets. An alternative is to just drain the float bowl, disconnect the line and-lightly-spray compressed air where the fuel inlet is-that may clear the sediment, which may be rubber fuel line particles, a paint chip, or tank rust. I also recommend you remove all your spark plugs (they will be fuel fouled) and, with the line off the carburetor and plugged, spin the engine over to purge any unburned fuel. Replace with fresh plugs., reconnect line and give it a shot.

Once you are up, running and warm-go change your oil. It will be fuel contaminated and you could "wash" a bearing. To avoid this happening in the future, you could try running the engine out of fuel prior to winter storage. This is accomplished by clamping the fuel hose before the pump with a clamp, or rag covered pliers to avoid shredding the rubber line. Remember to check the tank for sediment and feel the rubber lines for too much softness-they should be firm-not spongy. Hope this helps.

Rick

 

[studiog]

I agree with all the good advice above. You may also want to keep a fire extinguisher in the garage too, just in case.

 

[atmmac]

Get a can of starting fluid and spray it int he top of the carb. Do this next time you start it up. This will clear it out and it should fire right up. If it doesnt and you are smelling gas just stop. Ive actually had my impalas carb catch on fire a few times. Eventually i just got a new one.

 

[bobmanx]

Thanks everyone.

I was hoping that it was something simple to fix, since my limited Corvette knowledge is growing slowly. I was parusing the factory workshop manuals and trying to become more familiar with whats involved to pull it a part. And yes I could see where it could have been very dangerous with all that gas everywhere.


Thanks again for the places to start.

Bob

 

[wishuwerehere82]

Bob,

If the float is stuck, you could try tapping the carb a few times to loosen it with the coil disconnected. In most cases varnish is the problem, although you could have a cracked float that has filled with fuel.

 

[carrollm]

I agree with Pete. If it is a HOLLEY carb, it is the float. (stuck, or sunk), I would replace (or at least clean) the needle and seat. You can get replacement needle/seats cheap from JEGS 1800 345-4545 pn# 510-6-504 for 12.99 ea. floats are are 9.99 each. Have a competent mechanic put them in for you and drive your pride and joy with confidence. I have cleaned up old needle and seats, just to have them stick about 10 miles down the road. You don't need that to happen.

64 mike

 

[bobmanx]

I agree with Pete. If it is a HOLLEY carb, it is the float. (stuck, or sunk), I would replace (or at least clean) the needle and seat. You can get replacement needle/seats cheap from JEGS 1800 345-4545 pn# 510-6-504 for 12.99 ea. floats are are 9.99 each.

64 mike

Mike, Pete and everyone,

Thanks for the responses, I think that replacement of the needle/seat and float is well worth the safety factor. In less than a minute there was gas dripping down on the garage floor, and one small spark could have ended the life of the Corvette, myself and others in the house.

Yes it's a Holley, it was rebuilt several years ago, but the car sat for a few years until it was transported to SoCal from Tucson when my uncle passed away. I would not want the car to join him. I will get the carb model # and call Jegs, new parts will be purchased and installed and I will wait to see what gremlins are still awaiting exorcism!

I will get more info on the holley when I get over to my garage again, about 80 miles and one of the reason's that it was such a long time between starts/running.

Thanks for the help and knowledge of every one here, you are all more than willing to help in any way possible when something happens.

I will advise when she's ready to fire again.

Bob

 

[carrollm]

Good luck Bob. Keep us posted. If possible, have your mechanic show you how he/she adjusts the float level. This is always good to know.

Here's a good resource for carb troubleshooting:
http://www.recarbco.com/technical/newtrouble.html


64 mike

 

[My Prozac]

If the float is not stuck try the neddle and seat. I had an old 72 Monte Carlo do that very same thing, with out the air cleaner on, it would shoot gas out of the top of the carb about 10 inches, and that fuel pump was only putting out about 7psi I am sure yours maybe more psi. After tearing down the carb I found some paper from the filter had gotten in and would not let the needle close

 

[bobmanx]

carrollm, My Prozac, and everyone,

I will pull it apart and get new parts to replace the float, needle and seat, after getting the holley P/N off the carb. The tank is new and knock on metal the lines are new, another check. Is there a fuel filter other than at the inlet to the carb, hidden some where else? I didnt get a whole lot of time to play as I was being told we had to leave soon, over and over. I decided to clean up the gas, and air out the garage, and get "that damn gas smell off me". LOL Rather than looking for more trouble. Cant live with'em, cant live without'em complaining, etc.........

Thanks for the help and knowledge. I will let you know what happens.

Bob