blatantb Posted February 3, 2010 Share Posted February 3, 2010 A few months ago I bought a 87 gl with 92k on it and have been doing some little things like replacing the plugs/wires/cap, pcv valve, all the filters, the alternator and battery, had an exhaust leak fixed and more recently cleaned the carb with some of that spray stuff. It was running REALLY great! until... Yesterday, after tightening the heater hose which I deemed to be loose, the car started intermittently sputtering and then dying at idle. Sometimes. Other times it will idle right around 750-800 just like it should. I also notice that it isn't quite as responsive when it's dying as opposed to when its running fine. Today I took the can of cleaner to it again and took it out on the interstate and it seemed to die less and run better but then quickly went back to dying. It seems to drive ok but will die at lights and stop signs. I took it to a mechanic friend of mine's shop and they were stumped. Any suggestions? Clogged jet? Failing valve? Thank you much in advance for answering my first post! Link to comment Share on other sites More sharing options...
Gloyale Posted February 3, 2010 Share Posted February 3, 2010 These problems are ussually from vaccum leaks. Possibly from hoses. Replace any hardened and crusty vac lines, PCV lines. And put real clamps or at least zipties tight around your PCV lines. Worst case is if the throttle shaft has wear, and cleaning the carb loosened crud that was keeping it mostly sealed. Cleaned out, it can be a vac leak around the shaft. Start with the hoses. Espescially the PCV. When replacing the smaller vac lines note that a few of them have small pellet like bits of metal in there with a pinhole in it. These serve to reduce or meter the vacuum to certain portions of the system. Make sure to look in the old lines for them, and put them into the new ones. Link to comment Share on other sites More sharing options...
blatantb Posted February 3, 2010 Author Share Posted February 3, 2010 Yeah I've been thinking vacuum leak but I've been unable to find anything. I'll try spraying around the hoses again to see if I can find anything, especially under the air cleaner. Is it possible that its something like the egr sometimes being stuck open? Wouldn't a vacuum leak make it idle higher? I guess it might depend on where it is. Thanks for the input I'll be spending some time on it tomorrow. Link to comment Share on other sites More sharing options...
naru Posted February 3, 2010 Share Posted February 3, 2010 Yeah I've been thinking vacuum leak but I've been unable to find anything. I'll try spraying around the hoses again to see if I can find anything, especially under the air cleaner. Is it possible that its something like the egr sometimes being stuck open? Wouldn't a vacuum leak make it idle higher? I guess it might depend on where it is. Thanks for the input I'll be spending some time on it tomorrow. Does sound like it could be the egr valve not seating properly at times. If you can get it idling smooth again,disable the egr by unhooking and plugging the egr vacuum line for diagnosis(no more bad running=sticky egr) Last one I had,egr would stick 10% of the time after the throttle was opened to cruising speed. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted February 3, 2010 Share Posted February 3, 2010 Is it a feedback model? GD Link to comment Share on other sites More sharing options...
blatantb Posted February 4, 2010 Author Share Posted February 4, 2010 Well I took some time today checking out as many vacuum lines as I could and didn't find any noticeable leaks. I started it and it idled great for about ten minutes, higher while warming up of course and perfect when I kicked it down. I plugged the egr line and decided to take it for a short drive. It ran reaally well and at the first 6 or 7 stops it was idleing great. Then it started dieing at idle again and did it the rest of the way home. So I think the egr might not be the culprit. Is it normal when a car is dieing like this for the voltage to be low (12ish) and wavering when it's below 750 or so? It sits right at 14 when it gets going like it should. Link to comment Share on other sites More sharing options...
blatantb Posted February 4, 2010 Author Share Posted February 4, 2010 Is it a feedback model? GD No its not it has no o2 which I believe means its not. right? Link to comment Share on other sites More sharing options...
blatantb Posted February 6, 2010 Author Share Posted February 6, 2010 So I've not yet been able to id the problem but I have noticed that sometimes when it's dying I can give it a little bit of gas a couple of times and it will stick and idle ok. Other times it won't do this. Does this indicate anything in particular? Link to comment Share on other sites More sharing options...
naru Posted February 6, 2010 Share Posted February 6, 2010 Carb might be flooding.Opening the throttle clears the excess gas from the manifold sometimes. Get a look at the fuel level in the carb sight glass.Mirror? I`m guessing the float valve leaks and the fuel level is too high. Link to comment Share on other sites More sharing options...
blatantb Posted February 7, 2010 Author Share Posted February 7, 2010 Carb might be flooding.Opening the throttle clears the excess gas from the manifold sometimes. Get a look at the fuel level in the carb sight glass.Mirror? I`m guessing the float valve leaks and the fuel level is too high. hmm yeah i was discussing that with one of my friends just last night. I'll give it a look. If that turns out to be the case do you think the valve is just clogged open or shot? Maybe I should just try to rebuild the carb and replace/clean everything. I have pretty much no experience with carbs but I'd really love to learn how to work on them myself! Link to comment Share on other sites More sharing options...
brat82 Posted February 7, 2010 Share Posted February 7, 2010 Time to check your fuel filters, for water and crud...? This might tell you something about what might be running into the carb Link to comment Share on other sites More sharing options...
blatantb Posted February 7, 2010 Author Share Posted February 7, 2010 Time to check your fuel filters, for water and crud...? This might tell you something about what might be running into the carb Yeah I just replaced it maybe 1k ago but i've used some fuel system cleaner since and that probably loosened some crud up so i'll check it again. Link to comment Share on other sites More sharing options...
brat82 Posted February 8, 2010 Share Posted February 8, 2010 Yep, that is the other thing I try before messin with the carb...mechanic in a can and I've had good results. Funny thing driving from oregon to arizona, seemed to get better gas and even get better milage in Nevada. Link to comment Share on other sites More sharing options...
blatantb Posted June 5, 2010 Author Share Posted June 5, 2010 just to update... after triple checking my hoses and not really figuring anything out, I put a half a can of seafoam into my tank and that definitely cleared up the problem. I had run other cleaners through a few hundred miles previously but seafoam just did the trick. I did replace my fuel filter afterward as a precautionary measure. anyway it runs great! idles around 700-750 and i recently put some seafoam into my crankcase 80 or so miles prior to my last oil change and i have noticed a dramatic improvement! that stuff is amazing! Link to comment Share on other sites More sharing options...
Subarule Posted June 6, 2010 Share Posted June 6, 2010 How old do you think all the vacuum lines are? Do you think they've ever been replaced? My advice: replace every vacuum line with brand new and then you have a starting point at which to diagnose any problems from that point on, unless replacing the hoses cures the one you're having now. Starting with all the lines brand new gives you a baseline. Something that you know is good and that you don't have to worry about.. Link to comment Share on other sites More sharing options...
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