Recently I wrote to you guys about an issue with my 1980 L82. I had a new Edlebrock carb put on right after I bought it which helped everything but 1 problem, hot starts. With the old rebuilt carb, or my new Edlebrock, I still had the same problem, it starts great first thing in the morning with no smoke and anytime after it has sat for less than 15 minutes, but anything over 15 minutes and I have to crank it longer and then when it does start I get some smoke! It turned out that my heat riser valve had been welded in the closed position by the previuos owner. I had the valve removed and found new power I never knew I had! I figured this would also solve my hot starting problems but it didn't completely. It has helped but I am stilling having problems. I have a fuel regulator in line and set for 5.5 lbs, and I have as much of a heat insulating gasket as my hood will allow. The only thing left that I can think of is that the fuel line is heating up. Someone told me that the original Quad carb had the fuel line coming off of the front where my Edlebrock is coming off of the rear side. They think I have more line now to heat up. Any idea's?

 

More than likely its the old heat soak problem. Check to make sure that you have a good ground. The big insulated wire on the starter runs to the frame. Also make sure you have a good battery. You can purchase a heat shield to cover the solenoid. As far as smoke is concerned, can you see it with the hood raised? Check for leaks.

 

On a hot start the starter turns just find, along with the motor, it's just that I would like the motor to fire immediatley rather than crank, crank, crank and then start and then act like's it's kind of fluded, along with the puff of smoke! I don't see any smoke at all under the hood but I have noticed, and heard, sounds from the carb after I have shut it down. I'm thinking its boiling, maybe! I have a chrome fuel line coming off of the passenger side rear of the carb going down almost to the intake. From there it turns for about 4" and then into a 2" rubber hose that is connected to the in-line fuel regulator I put on. After the fuel regulator is about a 4" rubber hose than then connects the the original metal gas line heading down to the fuel pump. I'm wondering if I am heating up the gas line? Someone said to wrap it with a automotive heat tape but none of the part stores around here have anything like that. I would assume that rubber is a better insulator than metal so I'm wondering if I need to replace the metal coming off of the carb with rubber. Again if I start the car back up within 15 minutes or less I don't have a problem. If it's been more than 15 minutes I do, or if I wait about 3 hours its fine. The hotter the weather the worse it is! Any new idea's?????

 

It sounds like you may be boiling the gas out of the carb when you shut it off. It takes a while to clear the excess fuel when you try to start it so it acts like it is flooded.

Have you fully blocked the heat riser passage between the head and the intake yet? Now that the heat riser valve is gone you can do this. 1980 Vettes use an aluminum intake so drivabillity should still be pretty good once it warms up fully. It might take 15 minutes or so to warm up but this will help with the carb boiling issue. The heat passage is right between the center most intake to head bolts on both sides of the engine. You can slip a stainless steel shim in there to block it completely and cut the carb heat way down.

-Mark.

 

I like the sounds of that but your talking to a guy who isn't very keen on mechanics! Can you explain that to me a little better please? Do I loosen the intire intake to do this or are you saying I will need to take the intake off? And with a shime in there will I run a risk of leakage?Thanks, Mark.

 

What type of choke do you have? Is it hooked up?

 

I have a new Edlebrock carb and the choke is hooked up. I noticed in your photo that your gas lines are much higher up than mine. Do you think I am picking up heat by having my lines lower? My fuel regulator actually sits pretty much on the intake.

 

It is difficult to diagnose these things from afar. My carb is an Edelbrock #1406 with the Edelbrock/Russell 90* fitting off the carb with their in-line filter as well. The filter to pump line I bent myself to keep it well clear of the intake and block. It may well be that your line and regulator are too close to the intake and you are getting fuel boil and/or vapour lock on hot engine shut-down. But that does not explain the apparent rich condition on hot start-up?? To keep things simple I would try a drive with a non-combustible, insulating material between the fuel line and intake to see if that solves the problem. If yes, you can get heat wrap at Lowes/Home Depot.

Just as an aside, I would be concerned about rubber in a fuel line. My preference is all steel. Also, you did not mention a gas filter. Unlike the Q-Jet or Holley the Edelbrock does not have an internal filter and does need one.

The pic will give you a better idea of the line spacing on my car.

 

Thanks for all your help! The mechanic who put my carb on does have an in line filter installed. What type of gasket material are you using under your carb? My mechanic just tried to add a thicker gasket but my hood would not allow it. It appears I have an aluminum gasket sandwhiched by 2 thin rubber gaskets. I have often wondered why this problem never happened when these cars where new? Or did it? The car runs great, it's just frustrating when it doesn't fire immediatley, after a 15 plus minute break, and I get that puff of smoke! I had the very same problem with the old rebuilt that was on it. Of course the old rebuilt was shot and needed to be replaced. I just figured that the new Edlebrock would solve that problem! Oviously its not the carb!

 

I have a phenolic 3/8" heat spacer (again from Edelbrock) under the carb. But I have a hood with lots of space (see pic). With the small block hood I had to use a 2" air filter.

The fuels of today are more volatile than back then. Hence more of these problems occur. I had to abandon my original Holley because of fuel bowl boil. The car would run but on hot engine shutdown, the bowls would boil over onto the intake. A lot of heat radiates in the absence of fan and driving airflow. There are carb base heatshields such as came on early 1970s LT-1s (and now Moroso, Mr. Gasket) but it did not work for me.

BTW the thermal reflective tape you see on my fuel line comes from a roll designed for sealing furnace ductwork. A bit of a Bubba prevention....it has not been hot enough here to know if it works.

BTW, I drove a 1979 L-82 for 17 years. Loved it.

http://img.photobucket.com/albums/v1...pring07007.jpg

 

paul is right on.
u can pop the hood, where possible, while u try things. some gas is worse than others. some boil at 140F

 

Bare with me guy's, I'm new to this! Are you saying that you have more hood clearance because you went to a shorter air filter set up, and if so, are you thinking that I might need to do the same? If I am understanding everyone correctly, it's important to have as much air flow over the carb area as possible, and that I can understand! Now when you say "pop the hood" what exactly do you mean by that? Are you saying that I just need more room so I can put on a thicker gasket? You guys are a big help to me so please don't stop now! Greatly appreciated!!!! Mark.

 

Mark,
Can you post a pic of your engine?

 

open hood, if it's not windy.
.
i'm surprised nobody has used a pc fan to duct in cool air(w/timer)

 

I will take some pictures this weekend. I don't have anything right now. As soon as I have them I will post them. Thanks, Mark.

 

Thanks. I would like to see your setup. Can't be more helpful until then.

 

 

i had fuel boiling, and opened the hood, it never boiled hood up.
inthe 90's i devised 2 fixes.
#1 pumped the fuel back to the tank(1994); but the carb got vapor lock.
#2 trapped dripping gas in the intake(1997). never has been hard to start hot since, no more open hood. U see, raw fuel would run into a few cylinders, creating flooding, while others were too lean. A simple 1/2" high barrier is all it takes, with JB weld. I am surprised how well it works, as it sounds BUBBA a few years later i read Vizard's book CARBS & INTAKES and he said such a barrier improves fuel distribution and increases power. so it's really ANTI-bubba.

 

It was Memorial weekend so I took some time and got serious! I decided to see just where my gas line was running. There was a maze of hoses that my gas line passed under and so I never really knew just where it was. Long story short I found that the steel line coming from the fuel pump passed over, and even sat right on top of the heater hose going to the intake. The gas line had even made a slight impression on the heater hose, thats how close the gas line was to it. Anyway I re-routed the gas line so it is above all heat sources and is more exposed to the fan. This weekend all I saw was rain so I didn't get to drive it much. What little I did has just about proven to me that maybe that was the problem! Lets hope. I didn't think to take pictures but lets see if I have fixed it. I'll report back. Thanks for everyone's help. Mark from Kansas!!