*******UPDATE*******: The problem is the big black thing at the top of the cylinder, not the plugs/wires/distributor. The black box that sits in the cylinder on top of the spark plug is the iginition coil right? I'm doubting that NAPA will have one for a volvo... any tips as to where I should order one online?

If this belongs in the s70 forum, sorry. I figured it was a pretty generic question.

Well, being a 17-year-old, I have to love cars right? Unfortunately since neither of my parents is much of a car person, I am kind of on my own. I drive a '99 S70 GLT w/ 106,000 miles. Because I had never done much on my car, I decided to pull out a spark plug, just so I'de know I was capable of replacing my own. Everything was fine, and I took out a couple of plugs and put them back in snug (without over-tightening, and making sure to label the wires). The problem is that one of the plugs isn't firing (shakey idle, engine shakes when quickly rev'ing between 2-3k, definite reduction in power).

I took out the two spark cords that I had removed earlier. I noticed that if I only removed a particular cord (call it #1) there was no change in engine noise/rattling/idle when I started it. So I figured #1 was not firing. One at a time I took off part of the plastic piece at the end of the cord so that the little wire coil that holds the spark plug was exposed. I set it up about 1cm above the block and briefly ran the engine. #2 sparked the gap easily as soon as I cranked the engine over, but sure enough, I couldn't get #1 to arc the small gap. So at least I ruled out the possiblility that I damaged the plug while removing it.

So my best guess is that there is a short in the wire somewhere, or that when I was taking out the spark cords off I somehow broke something... By the way, the black plastic casing around the sets of wires (about 1 cm diameter) crumbled at the touch. I don't see what I can do from here besides take it to the shop and explain that I don't think this particular cylinder is firing and that I don't think the problem is the plug.

Thanks for taking time to read this!

ANY IDEAS/COMMENTS?

Oh, and how harmful is it to drive with a cylinder not firing?

-pawn256

PS: hopefully you'll be seeing more of me around here.

 

If you did that much you can put new plugs and wires in yourself. Buy a new set of plug wires and plugs and put them on the car. You probably should get the distributer cap and rotor and the same time. If you can remove the plug, which you did, you can change the plugs and wires and save a good bit of money. The easiest way is to just do one cylinder at a time. Just make sure you run the wire from the distributor to the plug the same as what you are taking off. I would go with OEM parts, but many like the Bosch plugs. These cars about as easy as it gets to change the plugs, trust me.

 

Just wondering if you checked to see if you are getting electrical spark from wire #1? You might be losing spark at distributer level.

Personally I would follow jims advise. take it step by step. replace plug and see if that is problem, if not, change wire from distrubter. (haha) long time since I had one of those. if you are still not getting spark replace your cap and rotor. sometimes they crack and you will loss spark.

Dont drive around with on one less cyl. Not good for car.

DONT BUY BOSCHE PLUGS THEY SUCK, GET OEM'S (unless you are non turbo)

 

The problem is the black box that sits on top of the cylinder and connects to the spark plug, that is the ignition coil right? I assume my local parts store won't have one... Any tips on the best site to use ordering online? Thanks.

 

Jim and Zigzag Look at what Year his car is. It is a 1999. It has coil packs.
I would say the coil pack is bad.

Try swapping 1 and 2 coils and see if the cylinder changes on which is firing and which isn't.

Im not sure who sells them Aftermarket. You might have to buy one at the Dealer.

Don't worry about the Black sheilding over the wires it does it on all the cars. If you really want to replace it I think Walmart sells it.


By the way I moved this post to the S70 forum.

 

So in 99 they went to a coil per cylinder. I did not know that. I learned something today. Sorry for the bad advise there Pawn, just trying to be helpful. One thing yoy will learn on this board is to trust TECH, he knows what he is talking about.

 

Yes in 1999 they did.
Thats what I love about this forum if I or someone else makes a correction them it isn't world war 4!!

 

My dad had a 1996 960 wagon and it has a coil per cylinder.

 

Yes the 960 started in I believe it was 1992 with the coils.