Alex, I'm going to be dropping my tank and replacing at least the neck seal and examining it for rust to see if water is getting in any other place than the neck seal. I have new soft fuel lines, new fuel pump and new filter already installed, so I'm close to replacing the whole system if the tank is for some reason rusty. Keep me posted on your progress, maybe we can share horror stories

If I could just get to the root of my carb issues then I think I'm going to be in good shape. I just spent a small fortune on replacing much of the brake system...

 

VT.......

I remember Lars saying once that alot of problems come from the throttle body to manifold replacement gasket. They're not quite big enough to cover the vacumn passages in the base of the throttle body.

His post on this subject was recent. I'll go see if I can find it for you.

Alex

 

VT..... I found the info for you:

www.wiki.corvettefaq.com

Click on ENGINE then click on INTAKE......"VIOLA" there ya go

 

Thanks Alex. I'm reading that now. I've also made contact with Lars and I'm pretty much sold on sending it out to him for a complete overhaul and removal of all the previous mechanics bandaids or mistakes.

 

I was able to restart it this morning after some hesitation. I guess it was flooded last night and would not start... at least this means it probably wasn't water but just flooding.

 

You're on your way now. Good move getting with Lars

 

Okay... so if anyone is following this thread I will give you an update...

Since I read a lot of lars' papers he noted that timing has a lot to do with issues that people normally blame on carbs. I decided to check the timing this weekend and disovered some things...

Saturday:

I bought a digital timing light and RPM gauge combo, a vacuum gauge, a new fuel filter (to replace old inline one at gas tank), Iso Heet, carb cleaner, rotor, points, spark plugs and misc stuff.

I first checked the timing, since I didn't know what I was doing when I first hooked it up it initially read off the little timing gauge on the flywheel, something like 16 degrees. I then realized I needed the vacuum disconnected to check it. Once disconnected it was just a little off the stock timing of 8 degrees.

I stopped checking the timing and then went and checked the point gap and set it to the 0.019 as specified. I don't have a dwell meter but will be getting one soon. The points looked good upon inspection so I didn't swap them out. I checked the weights and they were moving freely. I replaced the rotor since I had gotten a new one anyway.

I went back to the timing and reset it to exactly 8 degrees. I fluctuates between 7.25 and 8.75 probably (estimates) and this likely means an out of spec distributor. It also could be a function of a later problem that I re-discovered (water in gas).

Once I had the timing in good shape and the point gap adjusted. I decided to check the condition of the gas. I had had problems with water getting in the gas tank and had spent a lot of time getting it out a while back and had kept in garaged since then. I had to have it outside for a couple months when I moved and I had it under a cover. But the Noah cover let's some water through the breathable fabric (i don't know why and annoyed by that). Well upon diconnecting the fuel line and cranking the engine I got a mix of gas and water.

So.... I unhooked the fuel line the the inline filter just after the gas tank and drained the tank. I got about 2 gallons of gas out and about 5 oz of water. The inline filter had mostly water in it. I swapped in a new inline filter. I put 5 gallons of fresh gas in it and a bottle of Iso Heet. I cranked the engine with the fuel line at the carb diverted to a jug and pumped out gallon after gallon (letting the starter cool in between cranking) of watery gas. After a long time of doing this I got to a point where I was getting about 1 oz of water for every 75 oz of gas. I was shaking the car to mix up the water and gas at the tank. Obviously draining the tank does not get all the water out since the drain is not the absolute bottom of the tank.

Well, I wore myself out doing all this since every bit of gas/water I was letting it separate and then pouring the back into the gas container and the water into the waste container. This ended saturday's fun.

Sunday:

I did a little more gas pumping and got out a few more oz of water. I decided to take the car for a spin and to see how she did. There is a series of streets that do a loop around my house that is about 0.50 miles and I did about 30 laps so I never got far from home just in case there was a problem. Going up the one hill resulted in the engine stumbling when I got to the top and I had to clutch in and pump the gas. Then is was fine all the way around until I got to the same hill and it woud stumble every time at the top of it. It stalled a few times and starter fluid got it going again. This tells me it's a fuel problem and likely the water in the gas and not just the carb.

Once I wore myself out driving it around (and annoyed the neighbors enough) I went back and let it idle for a bit and put in more Iso Heet. When it go down to really low I put in another 5 gallons of fresh gas. It seemed to be running well (but I wan't going up any hills or shaking the water around), but at the end of the day the idle seemed to have crept up from 750 to 1150. I had used some carb cleaner as well while it was running and perhaps it helped clean up a bit and the idle speed screw needs readjustment. I'll have to save those tests for another day.

All in all I feel like I have made some progress. Those laps around the sudivision were the most miles in over a year since I had brakes, starting, idling and water problems.

Also on Sunday before the laps around the neighborhood, I made a new cork seal for the filler neck and installed it. This should keep out any new water (although 1 of the 9 bolts snapped when reinstalling but it was still in tight so I left it to keep water out of that hole. When I do the resto, I will fix this. I put in a new rubber boot and drain line as well.

My main question is this: How do I go about getting that last bit of water out of my gas tank?? I don't want to take the tank out since I would have to probably cut the exhaust off and also would be dealing with some stubborn rusty bolts too.

Here are the options I have thought of:

1. Stay the course and just keep running it and using Iso Heet to get it out. Issues are inconsistent running (can't leave the subdivision), using Iso Heet, seems to be taking some time.

2. Install a fuel/water separator like boats have just before the fuel pump. My current boat with a 350 small block has one of these. This could be the best bet and install it temporarilty with zip ties. Once it has filtered all the water out then I am done and can take it out.

3. Drain the tank again then put an air hose down there and just push air into the tank for a while and evaporate the remaining gas and water until the tank is bone dry. Then refilling the tank with gas. Issues are, will take a while to evaporate the residual gas and water.

4. Find a safe system for sucking gas out of the tank through the fill hole. Issues, cost and that fact that it might not prime well and that I might not be able to reach all the corners.

Any and all advice is welcome, thanks in advance.

-Ryan

 

add 1/2 gal of methonal or
6 iso-heet
drive it!

 

Where do I get methonal? Is is safe for the car, hoses and carb?

I put in 3 iso heet's into the 5 gallons and have run about 3 gallons of that through. Can I over do it with Iso Heet and will that have a negative impact on the hoses, carb, or engine?

 

Where is this in line fuel filter?
I'm pretty sure you should only have a single filter if it's a Q-jet (I could be wrong)
I would jack the car up on an angle and siphon all of the fuel out of the tank and dispose of it. It doesn't take much water at all to foul things up.
Take the carb off and let it sit upside down over night.
The dwell meter is a good idea imo, more accurate and much easier than a feeler gauge.
Remember, when you change the dwell the timing changes as well so you will need to set the timing again.

 

When I origionally took this car in for the water problem the performance shop put a big inline filter about 8 inches past the gas tank on the line heading to the fuel pump. So it's hanging right there under the tank tucked in the frame. I replaced it just the other day as the old one had water in it. Are you suggesting that the filter back at the tank is adding too much drag or interfering with the q-jet? I'll yank it out if so

What do you suggest to siphon all the gas out. I don't like the taste I have a hand held vacuum pump that I guess I could make a longer line to go down in the tank and suck out the fuel, but I think my hand will get tired Any other methods of sucking the fuel out?

To get the carb off it's only the 4 main bolts, the choke linkage, the throttle and the vacuum lines right? I want to make sure I don't mess it up taking it out, since I'm just learning about carbs now.

I'm going to get a dwell meter for sure.

 

The inline filter may very well be limiting the flow but I'll let someone with more knowledge of this confirm it.

If you don't like the taste of gas then either use a clear hose so you can see when its getting to the end or find someone that doesn't mind drinking a little gas
But get all of that gas out of there

Rather than pulling the carb off, you may be able to get away with pouring a tiny bit dry gas down the vent tube on the Qjet to get rid of any water but it may damage the rubber on the accelerator pump. I know it causes problems on my snowmobiles that have a rubber diaphragm in the fuel pump

Again, maybe someone can confirm this.

 

I'm going to search some more on the inline filter and see what has already been posted on the net about having it and having issues.

I decided I could use my hand operated vacuum pump and a longer hose to do the siphoning for me and skip the gas taste The jacking it up to throw it all to one corner sounds like the best bet.

I hope the Iso Heet doesn't impact anything in the fuel system...

Sounds like taking the carb off is the only way to confirm there is no water in it.

 

I doubt it, people use it all the time.
I was only concerned about a large amount of it effecting the rubber on the accelerator pump.
I doubt a 1/2 ounce down the vent would hurt anything.

Whatever you decide to do with the carb make sure all water is removed from the rest of the system first or it will wind up in the bowl again.

 

Hello again. I'm happy to report that after my car sat for over a year with little efforts on my part, I was recently re-invigorated to work on it. (My excusese are spending too much time working on my Jeep and house and getting married).

Anyways, the other night I bought a hand pump for gas and used a long hose with a coathanger inserted up it to make a siphon that I could bend into shape and orient into the vette tank. I jacked the car up on one side and sucked all the gas out of the tank.... or should I say water. It ended up being that about 10+oz of water was still in there. I then used my compressor and blew air into the tank and left it running in the corners for a while to dry the tank to bone dry condition. I used a rod with rags zip tied to it to swab the tank bottom and pick up any bits of dirt, rust, and residual gunk. In the end the tank looked damn good inside.

Fresh filter and fresh gas then she ran great. Took it out and put a good 100 miles on her and it's SO great to be back in the Vette after my sabattical.

Looks like 95% of my problems were just never getting all the water out of the tank even after I replaced the cork filler neck seal. Since the bottom of the tank has ridges the water can luck down there and at any given time make it's way into the carb from sloshing.

I want to give a big thanks to all the responders on this thread as you all contributed to my success!