Thanks for the input on those steps. I remeber reading something similar to that and will follow those instructions.

 

What are the groups thoughts on getting a rebuilt Q-jet from Ecklers then bolting it on? Are they turnkey and ready to go and work well, or is the consensus something else? I'm a do it yourself kind of guy but for the time being carbs scare me..

 

Theres a far better chance that it will be much much worse than what you already have.
The commercially rebuilt Qjets are notorious for having many serious issues that can not be simply tuned out without having the proper replacement parts and knowledge of these carbs.
What ever you do, don't trade your original in for a core charge.
Basically, most commercially rebuilds are junk.

 

VT, I would hold off on puting on a new carb right now, until you're sure you have all the water out of your system. You can disconnect your battery cables, get a glass jar or something clear you can see through pull the fuel line off at the fuel pump, and let some gas run in it, about half full,or is it half empty,.lol. Then put your fuel line back on right quick. HAVE A FIRE EXTINGUISHER CLOSE BY JUST IN CASE!!!! Now look at the fuel in the jar, WATER and GAS do not mix, either water will be on the top, or the bottom of the gas, can't remember right now. If water is in there I would drop the gas tank, and get all of the water out, blow out fuel lines,then put on new fuel filter's, there's probaly one at the fuel tank, and one inside the carb where the gas line goes in. If there is water you will probaly need a new fuel pump also. I would also pull the carb, get the water out of it, and make sure the gasket is good between the carb and the intake (no vacuum leaks there) you can also make sure the screws are tight on the carb. Hope this helps.

 

Ok, something I didn't see covered in these messages in a quick read thru.

Speaking from the owner of a bought new 1972 350 automatic - here is something to look at...

After putting 2 right-hand mufflers on my car in about 4 years, I decided that my short runs were leaving a lot of water in the right muffler because the 'flapper' valve on the right exhaust manifold remaining closed on short runs, and not allowing water to be blown out of the right muffler, at least not as well as the left muffler, which had not been replaced while replacing 2 right ones.

Anyway, I had an idea! Just wire that 'flapper' valve on the right muffle open! Blow the water thru that right muffler. I did this in the summer and the car seemed to run just fine.

When the weather cooled off - I almost got rear ended a couple of times! The car still started and idled ok, but after stopping at a light a few blocks after startup, when light turned green and I gave it some gas - boom, it just died! And the person behind me almost whacked me!

That's when I found out that the flapper on a Qjet did a lot, mainly in cold weather. I allows exhaust to be routed thru a hole in the manifold thru the intake, in a crossover area directly under that carb! This heats up the carb quickly and keeps it from dropping dead like mine was doing.

When un-wired, my car than ran fine in cold weather. I just put a Midais lifetime muffler on the right the next time and stopped worrying about it.

So, is your flapper valve in place? Is it moving easily, they can easily rust up. Is the under carb exhaust heat tunnel open or is it full of carbon?

Something to check.

Also, if the main throttle butterfly shaft in the carb is badly worn, it will leak so much air around the shaft ends that you will never be able to get a stable idle messing with the idle screw. It will just leak too much air. This can't be rebuilt, as far as I know, a new carb is the only solution. Or some major machine shop work to sleeve the shaft.

 

It's quite common to find small holes drilled at the lowest point in the mufflers to allow the water to drain out. I have drilled my new ones and there were holes in the mufflers that were on the car when I bought it as well.

As far as the throttle shaft is concerned, it's not a big job to install new bushings but it is unlikely that thats the problem.

 

I have done the glass jar procedure to get the water out of the tank. I got it to have 99.9% gas coming out after a bunch of repititions. I think the gas tank is now all gas.

What I don't know is if there is water in the carb. It sounds like I need to take that sucker off and blow it out and check the gasket as you suggest. Is getting water ouf of a carb basically carb cleaner and shop air and turning it upside down? Never had to do that before.

I have a new fuel pump on the car, but it was installed in the middle of these water problems, so it has pumped some water since it was in. Do they go bad due to water? When I was cranking the engine to get it to pump the gas/water out to purge the tank it seemed to pump pretty good.

BTW, the water is heavier so it will be at the bottom (the reason it get's sucked into the carb when the tank has gas and water in it)

 

Is this the common consensus of the forum? What about getting a rebuilt one from a high end corvette shop not just ecklers. I was wondering why it was only $250 and no core, I was thinking it couldn't be rebuilt that well for that cheap.

 

Not sure I even know where to check this or what it looks like. I will get out my new Q-Jet books and have to read through some more to see what you mean.

I bought all the Q-Jet book Ecklers has

 

Here is a thread started by forum member Lars who has published quite a few papers on carb and ignition tuning.

http://forums.corvetteforum.com/show...ght=commercial

 

It's part of the exhaust. It is a valve between the right exhaust manifold and the start of the right exhaust pipe. There is a butterfly valve inside, with a coiled bi-metal spring on the outside. The spring also has a weight on the end of it - a hunk of iron.

Starting cold the spring has the exhaust closed off. Of course, if the rpm's go up, the pressure will push the valve open. But closed, it routes some of the exhaust up under the carb, heating it up, as I said in my first note. As the exhaust warms up, the bi-metal spring allows the valve to open more.

P.S. I've had a Qjet apart, but a long time ago. But I would think you could take the top off it, no need to take the entire thing off, and swab the gas and any water out of the bowls. Stuff the throats full of rags to keep from dropping anything down there.

 

Heat Riser

 

i definately don't see one of those on either side of my exhaust on my 72. I wonder if someone took it off? Did they all definately come with one?

could this impact the time it takes to heat up the carb, etc. and make it run like crap when cold?

 

Update... i took a closer look at the carb and tightened down the bolts holding it down. some seemed to be a bit loose. I also adjusted the idle mixture screws with some interesting results. I took them both out to 2.5 turns and the engine runs fine warm idleing.. i noticed that the main jet on the driver side is dripping at idle all the time and the passenger main jet was not. I was able to turn the driver screw all the way in to it's seat with the engine still idleing but when i tired the same with the passenger it stalled.

Is the main jet on the driver side supposed to drip like this at idle? I though the idle jets were under the throttle plates. I am thinking this is why it stumbles sometimes when I leave a stoplight due to collected fuel on top of the driver throttle plate ??

I did notice that the accelorator pump is working fine. I only notice the fuel blast coming in on the driver side and assume the accelorator pump only operates to the driver primary? I don't see the same hole on the passenger side and don't see any fuel blast on the passenger side when i throttle it.

The choke appears to be working fine from a visual inspection. It's open now that is is warm and was closed when it was cold.

anyone have ideas?

I didn't take the carb off to check the contents of the bowl (for water or dirt) since I haven't read enough on that subject yet. I was reading my manual and it wasn't clear how to check the fuel level in the bowl on the Q-jet. Since mine likes to stall when stopping at a stop sign I was thinking that might have something to do with an improper fuel level in the bowl?

 

I also just noticed the that the idle get's dangerously low when turning on the headlights. I assume the drop on the vacuum is impacting idle... could this mean I have vacuum problems?

 

it just stalled and would not restart on a quick spin up the hill. luckily i was able to push it and coast down the hill back to my house. Not sue why. I'm going to drain the tank and ensure there is no water still in there and aslo i guess i have to pull the carb and make sure it has no water in it..

soooooooo frustrating!!!!!!!!!!!!!!!!!!!!!!!

 

Lars......

Please come and rescue this poor fella. He's had enough. I think he's getting ready to torch it !!

Seriously, look into the "Tech" section of this forum and you will find very interesting reading on your problems.

 

I sent Lars a private message and hopefully he will help me a bit...

 

My 1972 automatic definitely had it. I would guess the manual would also.

And, yes, as related in my previous post, it was a real danger when cold.

 

Get all the info you can from Lars.

My car has the same symptoms as yours only much milder and less frustrating. It is going up on jackstands in a few weeks and the fuel system is getting restored from tank to intake manifold.