redwolf624 Posted February 28, 2014 Author Share Posted February 28, 2014 Pull the spark plugs, make sure they're clean and the right ones. Run-on can be caused by plugs holding heat too long or carbon deposits that are still burning, among other things. Lots of short trips where the engine doesn't warm up can cause depositing. i'll deffently check to see if they're clean, i know they're the right ones for my engine cause i checked into that before i bought em, Redwolf pulled the plugs they're all good but gapped at 35, called advance and they said the gap should be 45 so i gapped em all up to 45 and it runs better than it did and i won't know if it still has run on for another week or 2, Redwolf Link to comment Share on other sites More sharing options...
gogmorgo Posted February 28, 2014 Share Posted February 28, 2014 The smaller spark plug gap could make a bit of a difference in deposits as well. If you go for a good rip down the freeway, that should help clear things up a little. A good left-lane cruise, but don't really push it hard. Didn't really get to say this cause my phone limits posts to 255 characters, but my dad's old Chevy used to have a run on issue. He "cured" it by switching to premium fuel. I borrowed it for the summer a few years back, and pulled the plugs cause I didn't like the way it was running. Not only were they wrong (but not by much in terms of heat range) they had barely any electrode left, the gaps were way out, and they were mostly covered in carbon. I later found out they'd been in there since he bough the van 15 years earlier. New, proper spec and properly gapped plugs completely got rid of the run-on, allowed me to switch back to regular, and increased mpg's by 16%, despite driving it harder and faster than my dad ever did. He still doesn't believe me that it's fine to run it on regular, and despite him driving like a little old lady to my rally driver he's been getting on average 8% less mpg than I did that summer. Not to mention wasting money on premium. Link to comment Share on other sites More sharing options...
redwolf624 Posted February 28, 2014 Author Share Posted February 28, 2014 still runnin a bit rough, it's like a slight miss that normal GMs have and i still have a slight run on, could there be anything else? Redwolf Link to comment Share on other sites More sharing options...
gogmorgo Posted February 28, 2014 Share Posted February 28, 2014 Not a bad read. http://en.wikipedia.org/wiki/Dieseling#Potential_causes Based on what's in that article, I'd say check to make sure you've got the correct fuel/air mixture. Too rich and you'll leave deposits that can ignite fuel, too lean and you might be running too hot in the cylinders. You should be able to tell what kind of mixture you've got by looking at the spark plugs. Google to find out how. Or if you really want to shell out you could get a wide-band O2 sensor kit... Also make sure you've got a decent idle speed, no vacuum leaks, and the throttle isn't sticking open. Don't really have much else to offer you. In my opinion, carbs have been obsolete since the '60's, if not sooner. Link to comment Share on other sites More sharing options...
shelbyluvv Posted March 1, 2014 Share Posted March 1, 2014 Take a eye dropper and drip a few drops of water down the carb for a few minutes. Not a lot. Just a 10-20 drips a minute for a few minutes. The water will steam off the carbon deposits on the pistons and valves. Ever pulled a head and seen the cylinder with the blown gasket was spotless? Same idea on a safer scale. Link to comment Share on other sites More sharing options...
redwolf624 Posted March 1, 2014 Author Share Posted March 1, 2014 Not a bad read. http://en.wikipedia.org/wiki/Dieseling#Potential_causes Based on what's in that article, I'd say check to make sure you've got the correct fuel/air mixture. Too rich and you'll leave deposits that can ignite fuel, too lean and you might be running too hot in the cylinders. You should be able to tell what kind of mixture you've got by looking at the spark plugs. Google to find out how. Or if you really want to shell out you could get a wide-band O2 sensor kit... Also make sure you've got a decent idle speed, no vacuum leaks, and the throttle isn't sticking open. Don't really have much else to offer you. In my opinion, carbs have been obsolete since the '60's, if not sooner. i've been messin with the fuel/air mixture ever since i had this problem and it's not helpin any and i know bout carbs bein way out-dated but i didn't have the money to slap a computer in my MJ Take a eye dropper and drip a few drops of water down the carb for a few minutes. Not a lot. Just a 10-20 drips a minute for a few minutes. The water will steam off the carbon deposits on the pistons and valves. Ever pulled a head and seen the cylinder with the blown gasket was spotless? Same idea on a safer scale. water + fuel? doesn't that not mix too well? Redwolf Link to comment Share on other sites More sharing options...
shelbyluvv Posted March 1, 2014 Share Posted March 1, 2014 That is why you use a eye dropper. Small drips will not hydrolock it. I had a 79 Dodge Omni that would "diesel" after I drove it. A old man told me about the wayer trick and it worked. I've done it a few times on different vehicles. Link to comment Share on other sites More sharing options...
redwolf624 Posted March 2, 2014 Author Share Posted March 2, 2014 That is why you use a eye dropper. Small drips will not hydrolock it. I had a 79 Dodge Omni that would "diesel" after I drove it. A old man told me about the wayer trick and it worked. I've done it a few times on different vehicles. ok, i'll keep that in mind, Redwolf Link to comment Share on other sites More sharing options...
gogmorgo Posted March 2, 2014 Share Posted March 2, 2014 My point about carbs being obsolete was more to say that while I know a little bit about them (I've rebuild a couple), it's not really worth my time to figure out how to properly tune them. The few I rebuilt, I just cleaned them and put in new gaskets and stuff. Definitely not my area of expertise. That's not to say though that they don't work. Set them up properly and they can work really well. But fuel injection is just better on so many levels. I've never heard of the water-eye-dropper thing before, although it shouldn't hurt anything as long as you don't go nuts with the water. Sounds like something that would work to clean things up at least a bit. If that doesn't work, you might also want to try some good old Seafoam. Link to comment Share on other sites More sharing options...
redwolf624 Posted March 2, 2014 Author Share Posted March 2, 2014 My point about carbs being obsolete was more to say that while I know a little bit about them (I've rebuild a couple), it's not really worth my time to figure out how to properly tune them. The few I rebuilt, I just cleaned them and put in new gaskets and stuff. Definitely not my area of expertise. That's not to say though that they don't work. Set them up properly and they can work really well. But fuel injection is just better on so many levels. I've never heard of the water-eye-dropper thing before, although it shouldn't hurt anything as long as you don't go nuts with the water. Sounds like something that would work to clean things up at least a bit. If that doesn't work, you might also want to try some good old Seafoam. well i think today after work i'm gonna buy some gumout carb cleaner and try that, i'll save the water and seafoam as a last resort, Redwolf Link to comment Share on other sites More sharing options...
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