Should I try a fuel system cleaner before rebuilding the carbs? BTW it's been sitting for 2 yr's.
Only if you want it to puke slobber pop and backfire. generally if its clean / running okay let 'er go. If you are trying to correct evils, there are better ways. Speaking from experience (the wrong kind). That stuff is typically only okay for cars in a good state as regular maintenance.
If the car has been sitting for 2 years, the gas is probably suspect in some regard...moisture content, etc. My 66 corvettes sit for 6 moths and they take a full run though of the old gas every spring to really "clear" their throat so to speak.....and that is w/ fuel stabilizer every winter....BTW I've never owned a car w/ more than 1 4B carb....yet in my experience carb cars like to be used, driven and run hard. A carb car that sits, just seems to get gummed up in some manner that FI cars don't. I somehow think it's due to the poor effeciency of carb cars burning fuel. This is a totally un-educated theory, but carburation is an outdated tech...if it weren't we'd still be using it today. As such carb cars build up a lot of carbon on the exhaust valves, and tend to run iffy until that is either cleaned or burned out...JMWO. Run it out and see where you end up.
How about this for starters.. Install a new fuel filter. If you feel qualified, remove the main jets and idle jets from each carb (simple job), clean each with spray carb cleaner, and inspect with a magnifying glass. (It doesn't take much to clog those small passages). Re-install and run the car. If it runs OK, drive it. If not, rebuild.
If the car's been sitting for 2 years, unused and unstarted, chances are the gas in the tank is no good, and what was in the fuel lines and carbs has turned to varnish. So first question, when the car was put away 2 years ago, was gas stabilizer added to the tanks and were the tanks topped up? If not, chances are the car won't start, and if it does, will run really badly. If you haven't started the car, IMHO, don't. First thing to do is drain the tanks and get rid of the old gas. Start with fresh gas. Change the fuel filter. Disconnect the fuel line from the carbs, attach a long hose and use the fuel pump to pump fresh gas through. That will assure that any crap in the lines is gone and won't clog up the carbs. Remove the air filter and housing, expose the carbs, and spray them up with carb cleaner. Blow some carb cleaner through the fuel line to clean out the carb lines, needle valves, etc. Once you are sure all the line are clean and all the old fuel is gone, reconnect everything and try starting the car. You might want to let the carb cleaner evaporate before trying to start it. Once you get it started, it may run a bit rough until all the junk is out of the carbs. Old gas can cause a real mess, especially inside the carbs. So the best thing to do is get rid of the old and start with fresh fuel. Good luck and let us know how it goes. BTW, throwing a can or two of dry gas into the tanks before refilling with the fresh gas is a good idea. It will absorb any residual moisture that might be in the tanks.
Hey Steve, This is a lot easier said than done. I'm just curious....how do you get rid of old gas? Other than dumping it into the ground (bad!) or making a huge molotov cocktail (fun!) I can't imagine how I would get rid of bad gas. Birdman
I mixed the 10 year old gas I got out of my Fiat gas tank with new gas (1/2 and 1/2) and ran it in my lawn mower all summer.. Seriously, I did. Worked fine! Then again, my mower is a Honda, not a Ferrari.. haha
Drain the system at the cross connect piping underneath.. If there's that much you can't just kill the grass at the fenceline all the way around your house, inquire as to legal disposal methods in your area.. +1 on the fuel filter also, never a big deal there... James has a point as our systems don't vent the tanks directly to atmosphere, still I wouldn't run old gas....
When I pulled the engine two winters ago, I disconnected the fuel line from the fuel pump and ran it directly into a jerry jug/gas can. Almost filled three 5-gallon jugs. Most of it we used to fill my SUV, and two of my friend Paul's cars just to get rid of it rather than having it sit in the cans for a couple of months. But that was fresh gas. As for the old fuel, as noted, either use it up in your lawn mower, garden tractor, etc. or contact a local garage and find out if they can take it off your hands. Otherwise, a chemical disposal firm, I guess. Don't pour it down the local sewer or into your neighbor's garden (unless you really, really hate your neighbor).
Just a thought, when I first bought my 308, one of the things that has to be first clas is the fuel system. So, filter, carby kits- needle and seats gaskets etc, fuel lines and related return lines. Never had a problem since. Nothing worse than a engine bay fire. It was a bit of a job but well worth it. Cheers MG
I would pull the return line from the right front carb and install a 5/16ths fuel hose and fill gas cans untill the tanks run "dry", then fill with new fuel and drive it. My old toyota work truck would probably run on kerosene, so i dump old gas into it and dispose of it that way. Might be a good idea to fire it up and look for leaks from any of the fuel or evaporative hoses before you go out and romp on it. hth, chris
Seafoam. Two tanks full in a row. Did the trick for me. Car sitting 12 years. Unfortunately, I still had to rebuild the carbs though because the plugs needed to be restaked. H
By the way, to answer the initial question with my own opinion.... If the carbs were not all clogged up to begin with, 2 years sitting and they may be OK. I would just yank off the airbox to gain access to the carbs, pull all the jets (especially the idle jets) and give them an overnight soak in carb cleaner. Then inspect that the orifices are clear, and re-install. At the very least, top the car off with fresh gas. If it is FULL of old gas and you can get a good chunk of it out to use elsewhere, that would be best. Location of the jets is illustrated on my website here. BTW, Techron fuel injector cleaner can often help with injectors, so I see no reason why it isn't worth trying with carbs. It won't hurt the car. But manually cleaning the jets will be a lot more effective. Birdman
in my opinion long periods of sitting are a much bigger problem for FI cars than carb cars. Because fuel injectors really dislike it and and are well known for making trouble. This trouble sometimes occurs after relatively short periods of sitting around. Periods which are absolutely no problem for a carb car. Say, for instance, over the winter. And while a carb system always can be cleaned thoroughly, some expensive FI components like the fuel distributor on the Bosch K-Jetronic can suffer from sitting. Especially this part cannot be repaired or cleaned properly and is BIG $$$$$. A Bosch K-Jetronic is a highly reliable FI system. I never hear of serious trouble with K-Jetronic equipped daily drivers. But all the time with rarely driven ' toy-cars' like Porsches of Ferraris. Best Regards from Germany Martin
Rubber connecting hose at cross connect is already off, tanks were empty when I brought her home due to the hose leak. I'll order filter today. Thx, Steve
