OK, I am a dunce, I guess. I am working on a 1962 model Chevy 235 in my '49 1 1/2 ton truck. I previously had problems with the ##### YF carburetor. I rebuilt it but it continued to dump gas out the bottom and even out the top after the truck was started. I figured I did something wrong in the rebuild, but could not seem to fix it. Now I have replaced the carb with the recommended Rochester B that I got from Autozone. I installed it with new gasket, started the truck and it fired up just fine. After running about 1 minute it started dumping gas out the bottom (around the throttle linkage) the same as the #####. After adjusting the mixture it seemed to stop. I drove it about 2 miles and it started missing and acted flooded. I checked, and sure enough, it was dumping gas on the exhaust manifold. I towed it home (I didn't want a fire.) I was told that the fuel pump might be supplying too much pressure, so I put a fuel pressure regulator in line between the pump and carb. I set the regulator at about 2 PSI. Still dumps fuel after running a minute or two. I have tried various settings from 1 to 5 psi. I can tell when it starts dumping fuel because the engine starts running rich and will eventually die. I have tried adjusting the mixture, but can't seem to make it happy. It will start right off when it is cold with just a pull of the choke and a couple of seconds of starter. It starts dropping fuel after anywhere from a minute to 5 minutes of running as it warms up. Any ideas?
Bossman ; It sure sounds like you have some silt in the fuel that's settling on the float valve and causing flooding to me ~ my old '46 used to do this during the hottest days of summer and it sorely vexed me as I'd spent some time getting that original uncut steel fuel pipe from the pump to the carby , eventually I had to swallow my pride and cut it and install a NAPA / WIX # 3001 filter at the carby inlet to cure this repeated problem . Are you using a stock mechanical fuel pump or an electric one ? if an electric one , get rid of it, there are 1.5 PSI electric pumps as the pressure regulators don't really function well at the low pressure we need in these old tech carbys . -Nate
Happy New Year, Nate. I have a small piece of the original fuel line running from the tank flex hose about 4 feet towards the fuel pump because I didn't want to hassle with bending that piece. I then have a brass coupling to a new piece of stainless that is about 2 feet long. This runs to a new fuel filter, to another piece of new stainless, to the mechanical fuel pump mounted on the engine right side (standard). This is the newer style pump without the glass globe since the engine is a '62. There is then a new piece of stainless to the regulator that is about 6" ahead of the new carb. The regulator connects via rubber lines as that is how it comes from the factory. I pumped the fuel line clean from the fuel pump before I hooked up to the new carb, but I didn't see anything in what I caught while pumping it out. Another old timer I talked to said that I may have gotten a bad rebuild from Champion (a supplier to Autozone). He thinks the bushing for the throttle linkage is worn excessively. I kinda think that may be the case. Also, the carb base is all dinged like someone in the past was using a wrench on the side of the bowl to get the float free. I have made arrangements to swap the carb back to Autozone for another one, but this one will be rebuilt by Holly instead of Champion. One more try for a few bucks more. If that doesn't work, I will start looking at the fuel pump as you suggest. Is it possible someone put the wrong mechanical pump on the engine?
RE: Flooding Problem Thanx , as it turned out I actually *forgot* it was New Year's Eve ~ I'm so lucky SWMBO is very understanding ! . All these things you're mentioning sound good to address -but- they don't address the likely culprit of tiny bits of....stuff getting lodged in the float valve . add a carby inlet fuel filter , either a paper typ (my favorite as they're Micronic) or a nifty glass bowl one . You can use either typ of fuel pump on your 235 but I prefer having the filter right at the carby inlet where I can see at a glance if that last tank full of fuel had dirt or rust in it . You're going to LOVE the Holly rebuild as they always re-bush the throttle shafts . IIRC Chevy Duty sells Holley rebuilds . BTW : loose throttle shaft does NOT cause fuel to ' gush ' out ~ only flooding can do that . a dribble out the ends of the throttle shaft is normal on the Rochester carby and indeed on many old carbys . You said when you are driving , the engine begins to die from flooding and then fuel gushes out the throttle shaft ends ~ this indicates flooding as when it floods the excess fuel comes up and out the float bowl vent pipe , that's the angled brass tube in the air horn you see when you remove the air filter . Keep at it , you'll get there eventually . -Nate
RE: Flooding Problem Thanks, again, for the info. I got a call from Autozone this morning that Holly cancelled my order since they are temporarily out of stock on that carb. Autozone is going to try again to order and see what comes up. I will follow your advice and put a filter at the inlet of the carb on the next install. I know the type you are talking about. I'll just leave the other filter in place, as well. I have looked at the filter at the inlet to the fuel pump and it looks pretty clean, but that doesn't mean that real fine stuff hasn't gotten past it. Except for this problem, the engine has been real reliable as far as starting right off, even on 6 VDC. I will keep banging on it until I get it 100%. The wife is working on a custom reupholstery for the seats. We are using a med blue marine vinyl with 12" dark Navy Blue diamonds behind the driver and passenger positions. Each diamond will have a couger head embroidered on it. There will also be a dark blue stripe between the passenger and driver sides. That will go nice with the light blue headliner and door panels I got from Chevy Duty. I'll snap a coupld of shots when it is installed in a couple of weeks. I promised a photo of the truck. It is attached. This is as purchased. I have more photos that I will process and send later. Attachments: https://talk.classicparts.com/images/attachments/43bee96b096c47cf.jpg
RE: Nice Truck ! That's a nice looking , straight old truck you have there . Yes , the Chevy 6 engines are _very_ good and reliable too once you figure out the little thing that's bugging you . Seats sound nice , I'm _still_ trying to locate an original seat back cusion.... Then I'll re-cover with original maroon covers . -Nate
RE: Nice Truck ! Thanks, Nate, I will send more pics once the weather dries out and I can get the interior installed. It really looks much better right now, but I wanted to show you what I was starting with. This rain has really slowed me down since the truck is too big to put in the shop to work on. Here in McMinnville we have had almost 11 inches of rain since Jan 1 and we had 11.75 inches in December.... 22+ inches of rain in a month and a half. Don't you live down at the other end of the state? If so, you must be getting webbed as well.
RE: Location Yeah , I'm in ' Sunny Southern California ' allright , we've had a few wet winters and I moved all the way from Down East to get away from just that . I heard on the radio to-day that Seattle has had like almost 30 days of rain non stop . ouch . I bought a spiffy new windshield grommet from Steele Rubber and some correct thickness glass from Chevy Duty thinking I'd slap 'em on in but so far , not yet doggone it and here comes the rain again saturday... -Nate
RE: Location, location, location rain!!! You guys should live in England - sometimes in maybe June / July we go two or three days straight without getting any rain (not every year of course). Mel
RE: Location, location, location Mel, That must be Jolly Old England. Here across the pond, New England has been known to go months without rain. http://iserver.chevyduty.com/dcforum/Images/happy.gif I thought all you had there was mysterious fog and creepy things going on at night. Oh wait, that's San Francisco. Nice to hear from you. I have attached a couple of photos of the recovered bench seat that the wife and I did. It is almost ready to go back into the truck. Not too bad for a first attempt. There is still some cleanup we need to do on the details of the cougers and then the white fuzzy stuff around the edges will go away. Attachments: https://talk.classicparts.com/images/attachments/43cd2e44008077de.jpghttps://talk.classicparts.com/images/attachments/43cd2f2903207a39.jpg
Throttle Shaft You can get your original throttle shaft re bushed by sending it to these folks. http://www.carburetors-rebuilt.com
