Guest livedrive Posted October 21, 2004 Share Posted October 21, 2004 OK, so in the last week the car's been running a bit rough (poor idle, and doesn't seem to have all the get up and go it normally does). I didn't worry about it too much b/c it hasn't seemed that serious, and I figured it was time for a tune up, etc... and I'd get it taken care of this weekend or next. All of a sudden I'm on my way home from work on Monday and while I'm sitting at a red light it completely dies. I try to restart it and its acting like the engine is flooded. I let it sit, and try again, and if I keep my foot on the gas while I'm trying to start it then it will eventually crank up (very reluctantly though). Once I have it cranked up I can barely manage to keep the engine running by giving it plenty of gas, and the whole while the car feels like it's about to choke and die. In addition there's tons of black smoke coming out of the exhaust and the air wreaks of gasoline. So I push it out of the street and take a look under the air filter to see if I can spot anything especially wrong with the carburetor. Nothing obvious jumps out at me, but I can say that on the 4 barrel carb the two rear barrels have a lot of black deposits on them whereas the front two look clean. In my limited understanding that sounds like a carburetor problem to me (too rich or something like that or maybe another prob) but someone else who was standing by and heard me trying to start it said something about a fuel filter problem, or having to blow out some gunk in the engine.... If anybody could give me some good info to go on that would be super appreciated. I'm also curious why it would have gotten so drastically bad so suddenly. Even info on how I could rule out one thing or another would be great b/c it is super aggravating. Thanks in advance guys, you're the best. Quote Link to comment Share on other sites More sharing options...
Guest 305240 Posted October 21, 2004 Share Posted October 21, 2004 Sounds like a fuel problem of some sort to me. You running an elect fuel pump? Sounds like your engine is flooded. Try unplugging the fuel pump and starting it then. Let it run as much as it can. It also sounds like you have a piece of trash under the needle and seat not letting it shut off the fuel to the carb. Whatever it is, it's letting way too much fuel into your engine. Time for a new fuel filter too. Quote Link to comment Share on other sites More sharing options...
Guest livedrive Posted October 21, 2004 Share Posted October 21, 2004 So, does it make sense for all of those things to be wrong at the same time, or is there some sort of decent way to diagnose which of these things is causing my problem? (I don't see anything physically blocking the carb.) Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted October 21, 2004 Share Posted October 21, 2004 When that happened to me it was a piece of dirt on the needle valve seat. The gas overflows into the carbs so the only way to keep the engine running is to rev it. Replace your fuel filter and open the top of the carb to clean out the bowls. You might consider rebuilding the carb if it has been awhile since that was done. At the very least use some carb cleaner to get rid of the soot and do a visual inspection of all diaphrams and gaskets. Quote Link to comment Share on other sites More sharing options...
Guest livedrive Posted October 21, 2004 Share Posted October 21, 2004 Cool deal. I'll get on that and give it a try. If anybody thinks of anything else to look at let me know! Quote Link to comment Share on other sites More sharing options...
BrandonsZ Posted October 21, 2004 Share Posted October 21, 2004 I've driven hundresd of thousands of miles on several carburators and they never fail "all of a sudden" I'd bet a hill of beans that it's something in the ignition. Rule of thumb if you smell gas and it won't start, but it was running recently, check the spark. Make sure the connectors are tight, check the coil, check the distributor, check the rotor, check the plug wires. A cracked rotor could do this, bad points. Once the rotor on my old caddy actually broke and the little metal sweep moved off center by 10 degrees like it hit something and that thing sputtered like a b, spent time adjusting things and then checked it. The cap was loose, so I accidently knocked it and the rotor had come in contact with one of the contacts, which knocked it off, just as I was adjusting the carb, which instantly made me think it was the carb. I save the carb as a last check nowadays, it's never bad in my experiance, but instead it wears out over time. Quote Link to comment Share on other sites More sharing options...
Guest 305240 Posted October 22, 2004 Share Posted October 22, 2004 Man o man! As much as I preach this, I don't take my own advice. Over 95% of engine problems are electrical. Check out your dizzy and all connections. Go to the fuel part last. Sorry. I tend to forget a lot in my old age here. Quote Link to comment Share on other sites More sharing options...
BrandonsZ Posted October 22, 2004 Share Posted October 22, 2004 Nothing wrong with Carbs as long as you are talking about the kind that sit on that V8. They're nearly foolproof out of the box and people who say they are having a lot of trouble "setting up" their carb usually have an electrical problem or a weak spark. Unless you want to squeeze that last Hp out of it, the carb is usually a set and forget plug and play thing (IMHO). Quote Link to comment Share on other sites More sharing options...
Guest livedrive Posted October 23, 2004 Share Posted October 23, 2004 Yeah, I haven't had any problems with my carb up to this point, but it hasn't been rebuilt in at least 16 months or so, and the fuel filter hasn't been replaced in the period either, so it's realistically time to do that anyway. If the problem was with the distributer or plugs, wouldn't it have more of a sustained sputtering or something like that? Would it still behave in the manner I'm describing while trying to start the car? (I'm referring to the flooded behavior while trying to start it, and it reluctantly sputtering up until it finally starts and then I have to keep my foot on the accelerator to keep it running.) If I need to replace my distributer, plugs, or stuff like that that's cool, I just want to make sure I start down the most likely path first. Quote Link to comment Share on other sites More sharing options...
GabeRoc Posted October 23, 2004 Share Posted October 23, 2004 i have had similar trouble with the float seat leaking. starts and runs ok, but shortly after stopping (and in some extreem cases while slowing down to stop) the engine coughs and dies. car hard to start afterwards, and in many cases wouldn't start until it has 'dried out' for 10 minutes or so. other things (than specks on the float seat) that might cause over fueling of this sort are high fuel presure, a bent/worn float tab or a worn seat/needle. best of luck! gabe Quote Link to comment Share on other sites More sharing options...
BrandonsZ Posted October 25, 2004 Share Posted October 25, 2004 The best approach IMO: 1. Check battery for weakness: -listen to the startup, those older V8 ignitions, needed a strong battery to spark through the points, when you are cranking over, if you have a slow crank like the starter is laboring, the battery voltge can drop significantly and the alternator isn't helping at that point. when the voltage is low the points fail to create enough spark. If you have electronic ignition, there are similar problems, just watch the battery. 2. Check your points(if applicable), cap and rotor. -A little corrosion here can cause a lot of trouble. Even on a late model car, the ignition module can become sensitive to heat when it gets old and open when the temperature is too high leading to poor performance, sputtering, stalling, and flooding (no spark to ignite also causes flooding). 3. Check the coil - A chilton book will tell you how to check for this. -Coils are pretty passive and usually rock solid, but can sometimes fail, and heat is a factor with it as well. 4. Check the plugs - Use Regular ones, not platnum. -Good platnum plugs last forever but have slightly higher resistance. -Sometimes when you have flodded the car the plugs will foul and they need to be removed, cleaned (might as well regap them) and be replaced. Also, shortening the gap to .035" can actually help a weak or old ignition system even if the system asks for .045". Now that you've spent the last hour and nothing is wrong? Now you can spend the rest of the weekend rebuilding your carb, shouldn't hurt unless you break something when you do it, or aren't following a good book and put it together wrong. Lastly, just pat yourself on the back for sticking with the Carb because your headaches only increase exponentially with electronic or computer controlled fuel injection troubleshooting. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.