Question: Spark Plub Vibrating...

[Gobbles]

I've got m car on jack stands and started her up since I changed the oil. Thought I would check somethings as well since I had a chance to look around with the hood up and her running before I went to change/repair the fuel injectors. I noticed that as the engine was at idle, one of the spark plugs was vibrating unlike the rest of the plugs I checked. I haven't had a chance to look too deep into it, but I just wanted to put that info out for now. Would that cause my engine to bog down or act as if its running on half a bank? I know its probably not a good thing that its vibrating, so I'll look into it tonight, but like i said, I just noticed it and wanted to get some info before I go to deep into it. Thanks for looking.


Tim

 

[bradfordsvettes]

it may just be loose in the head or the ceramic is coming loose in the hex base needs to be checked for sure Steve

 

[doublefoxed]

As of late I have heard many stories on plugs separating from the
ceramic. I have a Astro van that did just that 2x on ac delco plugs,
I switched to autolite and no problems since. I have a buddy that
use to swear by ac delco plugs but says he feels the quality control
is lacking.

 

[John Robinson]

Well one thing is for sure you have a loose plug. And yes you probable are only running on 7 cylinders most of the time.

The questions are which plug is loose. ( Could it be number 8 That is the hard one to get back in tight)

Did you change the plugs yourself or have someone else do it? If you paid to have the plugs changed recently take the car back to who did the job.

As already said the plug could have a broken insulator or it could be that it was not tightened up properly or the head was stripped.

Let us know what you find out.

I too have changed the plugs in my 93 recently and had to replace two of the plugs that had broken insulators which I believe I broke trying to put the socket on them.

 

[Gobbles]

I bought the car about a month ago and from the time I bought it I always thought I had an exhaust leak on the right side of the engine. Ironically enough, I changed the oil and started her up in hopes of stirring around the oil. We I was thinking to give it one good look at the exhaust just to see if I could see the hole/leak. That is when I noticed a spark plug jiggling. Right now its 2nd cyl on the right side counting from the front as being number 1. I'm reasonably sure that removing the tire and wheel well will make this a much easier job. Now my problem is removing the rusted on, now rounded lug nut. I rounded the nut with the lug nut remover, broke two wrenches trying to remove it with the special tool that bites into the nut to assit in removal. Well I'm on hold right now until i can get the nut loose and off along with taking the wheel well off. Will keep you all posted on what I find out when I get more into the job. Guess the replacement of the fuel injectors will have to wait until next weekend. Hopefully this will solve my other problems. Thanks for the help and concern.

Tim

 

[John Robinson]

I bought the car about a month ago and from the time I bought it I always thought I had an exhaust leak on the right side of the engine. Ironically enough, I changed the oil and started her up in hopes of stirring around the oil. We I was thinking to give it one good look at the exhaust just to see if I could see the hole/leak. That is when I noticed a spark plug jiggling. Right now its 2nd cyl on the right side counting from the front as being number 1. I'm reasonably sure that removing the tire and wheel well will make this a much easier job. Now my problem is removing the rusted on, now rounded lug nut. I rounded the nut with the lug nut remover, broke two wrenches trying to remove it with the special tool that bites into the nut to assit in removal. Well I'm on hold right now until i can get the nut loose and off along with taking the wheel well off. Will keep you all posted on what I find out when I get more into the job. Guess the replacement of the fuel injectors will have to wait until next weekend. Hopefully this will solve my other problems. Thanks for the help and concern.

Tim

Why are you wanting to replace the injectors? Do an ohms check of the injectors and let us know what they are. If they are 12 or better and consistent no need to replace them. If you are replacing them to make the car run better wait until you get the plug issue resolved since it may fix everything.

After you get the plug taken care of wait until it is real dark outside and fire up the engine and look for spark jumping to ground or down the plug insulator. Whenl you have the plugs and wires all working you may find the car runs just fine.

 

[Gobbles]

Well my first signs from this car were stumbling upon acceloration, hard to start once warm. And now I've found a loose plug, I'm going to replace all plugs and see if that makes any sort of difference in anything before I move on. My problem might be a simple as not having this plug in.

 

[John Robinson]

Well my first signs from this car were stumbling upon acceloration, hard to start once warm. And now I've found a loose plug, I'm going to replace all plugs and see if that makes any sort of difference in anything before I move on. My problem might be a simple as not having this plug in.

Have you done a pressure check on the fuel pump? It has to have 45 to 50 lbs of pressure for the engine to run strong.

Could you fill us in on the mileage of the car?

There are so many things to check before you start throwing money at it.

Have you checked the codes and if so did you have any?

 

[Gobbles]

I've got 150K on a 90. I haven't done a pressure check, but that was scheduled along with other things dealing with the fuel system. However, noticing the spark plug loose has sparked my interest. Here are some of the symptons that I've experienced thus far. Starts up great when cold, but once warm, it will crank like a champ and nothing. Once cold again, it will start right back up like nothing happened. Most recently I was out driving and once at a stop light idle was good. When green light, i proceeded to take off. Car stumbled and died. Once I got it fired back up, car ran on what seemed like half a bank, or like it couldnt' get enough fuel pressure (Just my explaniation). Keep stumbling or what have you until I turned it off at the gas station and called the wife. After about 10 minutes of sitting and trying to start her, she finally came to life. Acted like nothing had happened. I was on m way to drop son on at his friends house, so once I got there I was hesitant to shut her off. I did and well she sat where she was for the night if you know what I mean. Next morning, started right up and drove her home. Kind of baffled at this point. I know the plug needs to get fixed, so I'm planning on replacing them all today. Once I do that I will re-evaluate the sounds/performance and post with any other questions. I got the gauge for checking the fuel pressure from auto shop, just need instructions/pictures of where to hook up all hoses/parts. Will keep you info'd on what I find as soon as I find it. Thanks for the assistance and help. Any questions, just ask and I'll try to explain as best as possible. Thanks again

Tim

 

[G Winter]

Does it seem to have good power till it warms up? Power drop right along with warmup? I would put a vacuum gauge on it and see if vacuum falls off when you hold it at about 1800 rpm. If so you could have an exhaust restriction, such as a plugged cat.
My experience has been that injectors will cause a noticeable
miss.

Glenn

 

[Gobbles]

I really have no idea on that one. I never really got on it for the fact that it has 150K on it and I'm afraid that if I get on it, all four wheels will fall off leaving me sitting on the ground.