Running on 3 cylinders

[tercel4wdrules]

I had an unpleasant surprise this afternoon. I fired up the '83 DLX which I have laying around waiting for the day in which I will actually get some work done on it. I needed to move it, since I do not wish to receive a citation for failure of moving the vehicle and risk possible towing (one of the many vicissitudes of multiple car ownership without a place to keep them away from the street). I noticed it was stumbling and running real rough with blue smoke spewing out of the exhaust. That's usually how it starts when it's been sitting for a few days and didn't think much of it since it usually smoothes out after running for awhile. This time I heard exhaust backfire through the muffler, a sign that something was awry. I pulled away into the street and it was running real rough and felt like it was cutting out, along with bucking, not very pleasant. Then I noticed it was misfiring real bad, to the point it started sounding like a Subaru boxer engine, almost literally, along with a subsequent loss of power. I thought it would go away, but it didn't, so now I knew I had a problem. I drove it around for a little bit, then parked it and let it idle and proceeded to pull the spark plug wires to see if I could figure out which cylinder was dead. Cylinders 1, 2, and 3 had a healthy drop in rpm when I pulled the wires, but when I pulled the wire for #4, there was really no difference. At this point I'm thinking something is wrong with the piston rings for cylinder #4. When I first bought this car, it was running fine, with no visible smoke, but eventually it began to smoke under acceleration and now this. Could the rings be stuck? Would it helped if I sprayed SeaFoam Deep Creep into the cyl #4 spark plug hole in hopes that it might help free the rings? At this point, there are so many things wrong with the car it might just be easier to just dump it and take a hit with my losses. Any suggestions will be appreciated, just thought I would get some input on this issue.

[takza]

Do you have a locking gas cap? Keep the doors locked? I'd change the oil.

[Petros]

You should know better, if it only affects one cylinder it has to do with that cylinder, not oil or build-up or anything like that. A broken ring results in lower compression, but not zero, so I would say not likely (and not from just sitting too long).

pull the plug and inspect it, change the spark plug wire. Also check that the brake booster vac line that comes off that end of the intake manifold is not leaking (I had that once, no power out of the back cylinder, turned out the vac line was disconnected from the brake power booster, not an engine issue at all!), any other sources of vac leak at that end of the intake manifold should be carefully looked over as well.

If that fails do a compression check, if you have little to no compression the head has to come off at the least, than I would consider junking it if the car has no other virtues.

[tercel4wdrules]

Thank you for your suggestions. I will try and see if there are any vacuum issues with the intake runner leading to that cylinder. Then I'll check the spark plug and wire. If that fails, then I'll check the compression, but I hope I don't have to go that far. I guess we'll see what happens.

[blade]

ok i have had this a couple times and every ime for me it has been bad valve on mine it was the exhaust valve of 3 times. so maby thats the problem i would take the head of and look to see if is the valve but thats me and i dont minde changeng the headgasket. it saves me from haveing to scrap the block.

[tercel4wdrules]

It turns out that Petros was right, I should've known better. I went out to the car in the dark with my flashlight and pulled a good spark plug and wire from one of my other cars. I pulled the spark plug from this car and it was black and had oily deposits, a sign of burning oil. I swapped it out along with the wire and fired it up. Presto! It was running normal again. I went for a drive and then after I parked and let it cool down a little bit, I swapped out the spark plug again, but left the wire from my other car on. I started it and it ran just like before, now I confirmed it's indeed a bad spark plug. I'm relieved that it's nothing more serious, but the oil burning does have me a bit concerned. I'll have to think about what to do next.

[Petros]

I have found some brands of spark plugs give up regularly, mostly Champion (so now I do not use them). NGK and Nippondenso seem to hold up the best to my abuse. I have also had good luck with Autolite. I have never gotten the more costly small electrode type of spark plugs to last very long, so I just get the standards (less expensive) ones.

[tercel4wdrules]

The failed spark plug is actually an NGK spark plug. This is the first time I have a spark plug go bad like that. I like to use NGK spark plugs and plug wires, they work well. I haven't really tried any other brand of spark plugs.