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Concord won't idle suddenly |
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FSJunkie
AMC Addicted Joined: Jan/09/2011 Location: Flagstaff, AZ Status: Offline Points: 4741 |
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Great, now I have to see if my Eagle has the check valve in the return line or not. I didn't look for it before and now you reminded me. I wonder why AMC used the check valve with the BBD carburetor but not the YF. It says so right in the service manual. Both fuel systems are identical aside from the carburetor and the check valve. Something about the design of the BBD made the engineers believe that they could not allow pressure to force fuel back up the return line.
Edited by FSJunkie - Sep/14/2018 at 3:44am |
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1955 Packard
1966 Marlin 1972 Wagoneer 1973 Ambassador 1977 Hornet 1982 Concord D/L 1984 Eagle Limited |
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amcfool1
AMC Addicted Joined: Jun/18/2011 Location: roanoke va Status: Online Points: 1071 |
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hi, if you do not have a check valve, don't panic, any 1/4" one way flow valve will work. Go to Amazon and punch in "1/4" fuel check valve", lots there. I have one on my 84 Eagle, though truth be told it ran ok without it. The original is unobtainium unless you luck out with a parts Eagle in a salvage yard.
BTW, the CEC system is FORD based, NOT GM. The computer is still available (84+) from any parts store, though only the CA version, about $200. The 82 is different. good luck, gz
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george z
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Fahques
AMC Apprentice Joined: Jan/06/2016 Location: philadelphia Status: Offline Points: 49 |
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Ok, so this is what I came across while going through my vacuum hoses.
First thing I did because of the stalling was replace the fuel filter. I also replaced the PCV valve.The plastic casing of the valve was broken off at the bottom. When I started the car afterwards, within five minutes of running, visible exhaust started pouring from the hole in my muffler and tailpipe. Not just a little bit either. I took the good PCV out and the exhaust bellows were gone, so I left the bad one in. I saw that my sway bar links were shot and replaced them. I started tracing the hoses and noticed that the Sol-Vac was not connected to anything, no hose. The diagram I have says it goes to a vacuum switch or relay but I couldn't find it with all the mess of hoses and other things. I also noticed that there are a few other hoses that are loose, meaning not connected to anything. One of the hoses has a golf tee stuck in the end but the purple and orange distributor wires aren't cut as in the Nutter Bypass, not that I could tell anyway. I assume that the Sol-Vac controls idle so I turned up the outer idle screw ( the low idle maybe?) and the car ran fine in drive. In park it sounded like it was doing 40 MPH. for the time being i'll try to find a medium between the two so I can at least still drive the car. So at this point is it safe to assume that a vacuum "leak" is most likely NOT the problem? And it's something wrong with idle control, as in the Sol-Vac not hooked up? I also did a compression test after an oil change and discovered that my number four cylinder is almost dead. The other cylinders compression reading ranged from 125-155. Number four was 10 and the plug was not only black but covered in an oily gum. Next step is to pull the valve cover and that's when I'll go through the vacuum hoses further. I'm hoping that when the valve cover is off the problem is just a slipped rod or broken rocker or spring. Guess in the mean time I should get my hands on the parts. No point in pulling the valve cover off just to put it back on to take it back off. Any tips or insights would be a great help here. I'm not an ace mechanic or anything, I'm just trying to figure this out as I go. |
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Hanky Panky
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farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19610 |
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Well, checking for a broken rocker or bent pushrod is a first, but you may have a burnt valve. Blowing smoke could be a cracked or holed piston though, or cracked or stuck rings. Hopefully it's a minor issue, but one cylinder almost completely dead usually isn't... here's hoping for a bad rocker/pushrod! You will have to go through ALL the vacuum controls one at a time and repair them, or decide to remove them all and revert to an earlier distributor and carb. Or if the engine is bad maybe consider swapping a 4.0L in...
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Frank Swygert
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Fahques
AMC Apprentice Joined: Jan/06/2016 Location: philadelphia Status: Offline Points: 49 |
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The more I have trouble with the car, the more I'd like to swap it. But I'm prone to go through all the vac controls as much as possible. Looks more tedious than difficult.
Hopefully I'll be looking into the dead cylinder by the week's end, that will most likely dictate what happens next. And I'm hoping for a thrown rod or busted rocker as well. I'll post the findings when I pull the cover. |
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Hanky Panky
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Fahques
AMC Apprentice Joined: Jan/06/2016 Location: philadelphia Status: Offline Points: 49 |
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Sorry it took me so long to get to this but I just didn’t have the time.
I finally got around to pulling off the valve cover and I noticed that in cylinder number four, one of the pushrods was off it’s rocker. I’m not sure which valve is exhaust or intake but it was the rod that is closer to the back of the car. The rocker bolt in the bridge was not loose. Does that mean that the lifter should be suspect as to failure? Or should I just replaced the pushrod in rocker and that the valve cover back on ? |
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Hanky Panky
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farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19610 |
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It could be a collapsed lifter, could be a stuck valve. You should be able to push on top of the valve and get it to move. Will take a LOT of pressure though! Might have to remove the rocker and bolt a valve removal tool to it, or put the nut back on and pry down with a flat bar (such as used for nail pulling). If the valve moves freely you could have a bad lifter. You can put new lifters on the old cam, just put plenty lube (like a grease) on the end of the lifter when installing. I'd replace them all.. not that expensive.
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Frank Swygert
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Fahques
AMC Apprentice Joined: Jan/06/2016 Location: philadelphia Status: Offline Points: 49 |
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I put the push rods and rockers on, then hand rotated the engine. From the look of things, everything seemed to be working correctly. I just assembled them as TSM instructed and put the valve cover on. Getting that thing on and off is a nightmare. But anyway, the car ran fine. Better than it has as long as I've owned it. I know I got lucky so far and it wasn't a bigger issue but for now all seems good. The next time I do have that valve cover off may be lifter time. Or the next time i throw a rod. Thanks for all the info
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Hanky Panky
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tomj
AMC Addicted Joined: Jan/27/2010 Location: earth Status: Offline Points: 7522 |
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hmm... i'd be careful, you ought to assume something is wrong in there, as pushrods don't pop off for no reason. has
it ever run on really old gas? in the last decade or two old gas == bad
gas. it gums up and makes valve stems stick in the guide, and it
*never* washes out through use. probably not a coincidence that older
engines generally have crappy stem seals (age) and wear which seems to
make it worse. |
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1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5 http://www.ramblerLore.com |
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Fahques
AMC Apprentice Joined: Jan/06/2016 Location: philadelphia Status: Offline Points: 49 |
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Ok, I'll keep a close eye and ear on it. It's an 82 with 78xxx miles on it so you're right. Something is probably wrong. Not sure if it's had old/bad gas in it. Not since I've had it but I've only had it for 3years and the guy I bought it from said he just got it fixed so he could drive it and didn't do too much extra to it. He said it was sitting in a barn out in Ohio so and is 100% original so at some point it's likely it had some beat gas in it. I will say as long as I've had it, it hasn't been too much of a problem but definitely a learning experience. I tried getting a muffler for it locally and that was impossible. You have to be part MacGyver to fix these things. For right now I'm happy with it NOT chugging at 45 MPH and NOT stalling and NOT pushing exhaust clouds from time to time. It actually has some balls again. Especially climbing hills. I'll hope for the best and expect the worst
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Hanky Panky
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