# Cylinder not firing help!!



## Nbmx (Jun 28, 2011)

First off I had a problem with ignition so I simply replaced everything. Ignition wires, sparks plugs, distributor cap, rotor, coil plug and coil. The car started up however when it did start one cylinder wouldn't fire. It's getting spark. Gas is getting shot out of the exhaust. I'm a little confused as to why the cylinder wont fire and how I could fix it.


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## erty67 (Feb 23, 2010)

Nbmx said:


> First off I had a problem with ignition so I simply replaced everything. Ignition wires, sparks plugs, distributor cap, rotor, coil plug and coil. The car started up however when it did start one cylinder wouldn't fire. It's getting spark. Gas is getting shot out of the exhaust. I'm a little confused as to why the cylinder wont fire and how I could fix it.


did you check your timing and did you confirm the firing order is correct? just a random thought.


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## Nbmx (Jun 28, 2011)

erty67 said:


> did you check your timing and did you confirm the firing order is correct? just a random thought.


The firing order is right and I did not do the timing cause I don't have the light but I didn't move the rotor and put the cap back the same way. I'm sure I have to do the timing but could it really cause just one cylinder to not fire?


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## erty67 (Feb 23, 2010)

I'm no pro, but my thinking is if the timing is off the spark isn't that cylinder at the right time and might be missing the right firing point. it's a complete guess, but only takes a moment to check timing if you have a light. do you know which cylinder isnt firing?


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## ziddey (Apr 16, 2006)

Is this the same problem before you changed the ignition components? Have you determined which plug isn't firing?


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## Glegor (Mar 31, 2008)

usually, if you have a spark problem with the timing, or distributor, then all 4 cyls run equally bad.

when you have just one not firing, i would lean towards a bad wire, bad plug, bad compression, bad injector, something like that..


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## Fat Rabbit (Nov 18, 2001)

Since you say that you have spark at all four cylinders perhaps you have a bad injector -- pumping too much or poorly atomized gas into one cylinder. I'd look at the plugs first to see if one is soaking in gas. Or buy, borrow or rent a fuel pressure gauge and see how the fuel system holds pressure. But you will need to know which injector is open or otherwise messing up. A junkyard injector will work just fine as a replacement if you need one. Renew the "O" rings on all four injectors -- they probably need replacement anyway. FR


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## Nbmx (Jun 28, 2011)

ziddey said:


> Is this the same problem before you changed the ignition components? Have you determined which plug isn't firing?


It's a completely different problem. Before I just didn't have spark. Now I know I have spark on all four cylinders but just one cylinder won't fire.



Glegor said:


> usually, if you have a spark problem with the timing, or distributor, then all 4 cyls run equally bad.
> 
> Yea that's what I thought too so that's why I was unsure if the timing could really cause a problem like that.
> 
> when you have just one not firing, i would lean towards a bad wire, bad plug, bad compression, bad injector, something like that..


Well all the ignition stuff has been replaced so I know that it's not a bad wire or plug. The injectors were the next thing I wanted to test.



Fat Rabbit said:


> Since you say that you have spark at all four cylinders perhaps you have a bad injector -- pumping too much or poorly atomized gas into one cylinder. I'd look at the plugs first to see if one is soaking in gas. Or buy, borrow or rent a fuel pressure gauge and see how the fuel system holds pressure. But you will need to know which injector is open or otherwise messing up. A junkyard injector will work just fine as a replacement if you need one. Renew the "O" rings on all four injectors -- they probably need replacement anyway. FR


Thank you, I will probably be doing that this weekend if the weather holds out. The bently has some test for the injectors so I think I might go do that before I replace it so I can be sure it's the injector.thank you everyone for the help!


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## WaterWheels (Aug 14, 2005)

Nbmx said:


> . . . so I simply replaced everything. Ignition wires, sparks plugs, distributor cap, rotor, coil plug and coil. The car started up however when it did start one cylinder wouldn't fire. It's getting spark.


Going to assume you know it is getting spark by testing at the end of the plug wire. Try doing this: Remove the sparkplug from the cylinder that is not firing. Do it slow and careful as not to bang things around just incase it is what i think it could be or you may never really know. Look at the electrode of the plug real close. If you find a small piece of whatever between the two electrodes then clear it away and things should be OK again. This is a loooong shot but it did happen to me once. After installing plugs the engine ran on three cylinders, drove me a little nuts until I started grasping at straws and found the electrodes bridged with a piece of dirt or something. Seems it fell into the cylinder when the old plug was removed and then flew around in the cumbustion chamber during initial start-up and found a home between the two electrodes. I have talked with others over the years who also said it has happened to them so it is rare but happens I guess.


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## Glegor (Mar 31, 2008)

WaterWheels said:


> Going to assume you know it is getting spark by testing at the end of the plug wire. Try doing this: Remove the sparkplug from the cylinder that is not firing. Do it slow and careful as not to bang things around just incase it is what i think it could be or you may never really know. Look at the electrode of the plug real close. If you find a small piece of whatever between the two electrodes then clear it away and things should be OK again. This is a loooong shot but it did happen to me once. After installing plugs the engine ran on three cylinders, drove me a little nuts until I started grasping at straws and found the electrodes bridged with a piece of dirt or something. Seems it fell into the cylinder when the old plug was removed and then flew around in the cumbustion chamber during initial start-up and found a home between the two electrodes. I have talked with others over the years who also said it has happened to them so it is rare but happens I guess.


forgot about that possibility, ive had my electrode gap bridged with a chunk of junk before also..

good point you brought up Waterwheels :thumbup:


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## ziddey (Apr 16, 2006)

or even a dead spark plug out of the box. had that happen quite a few times. never with bosch yet though.


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## Nbmx (Jun 28, 2011)

WaterWheels said:


> Going to assume you know it is getting spark by testing at the end of the plug wire. Try doing this: Remove the sparkplug from the cylinder that is not firing. Do it slow and careful as not to bang things around just incase it is what i think it could be or you may never really know. Look at the electrode of the plug real close. If you find a small piece of whatever between the two electrodes then clear it away and things should be OK again. This is a loooong shot but it did happen to me once. After installing plugs the engine ran on three cylinders, drove me a little nuts until I started grasping at straws and found the electrodes bridged with a piece of dirt or something. Seems it fell into the cylinder when the old plug was removed and then flew around in the cumbustion chamber during initial start-up and found a home between the two electrodes. I have talked with others over the years who also said it has happened to them so it is rare but happens I guess.


I'll check for that tomorrow, not much time for car work on thanksgiving :beer: I hope it's a nice easy fix like that 



ziddey said:


> or even a dead spark plug out of the box. had that happen quite a few times. never with bosch yet though.


I don't think it would be the spark plug because I had one in and the cylinder wouldn't fire. And then I replaced all of them and still the same cylinder didn't fire so I doubt two plugs in a row would be messed up but who knows with my luck.


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## ziddey (Apr 16, 2006)

it's quick and easy to swap two plug wires around and see if the "dead cylinder" moves

can't imagine anything tricky as to why you're losing spark on one cylinder (as Glegor said, it's usually all or nothing).

unless someone is playing a trick on you welded on some metal, turning your distributor into a 3 window unit :laugh:


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## Nbmx (Jun 28, 2011)

ziddey said:


> it's quick and easy to swap two plug wires around and see if the "dead cylinder" moves
> 
> can't imagine anything tricky as to why you're losing spark on one cylinder (as Glegor said, it's usually all or nothing).
> 
> unless someone is playing a trick on you welded on some metal, turning your distributor into a 3 window unit :laugh:


That's the thing the I don't know if it doesn't have spark. I know there is spark to the plug but I don't know if the plug is sparking in te cylinder. It could be something else still who knows


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## Nbmx (Jun 28, 2011)

Problem fixed! I don't understand why but the brand new ignition wire wasn't gettin spark through to the spark plug. However when I pulled out the wire and tested it electricity would go through. And it was going through because it did shock me :banghead: so I yet again replaced that wire and car runs perfect again :thumbup:

Thank you everyone for all the help it was greatly appreciated.


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## WaterWheels (Aug 14, 2005)

Nbmx said:


> I don't think it would be the spark plug because I had one in and the cylinder wouldn't fire. And then I replaced all of them and still the same cylinder didn't fire so I doubt two plugs in a row would be messed . . . I know there is spark to the plug but I don't know if the plug is sparking in te cylinder. . . I don't understand why but the brand new ignition wire wasn't gettin spark through to the spark plug.


If you had listed that you had swapped around sparkplugs then I would not have had to make the post I made, but at least maybe it could help someone in the future. Glad you have it running but what you say about the wires and your checking for spark does not make a lot of sense. How did you determine that spark was getting to the plug but then say you didn't understand how a brand new wire wasn't getting spark to the plug? Maybe it's just me. It sounds like the wire was either not seated well or there could be a problem with one of the connectors on the end of the wire.


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## Nbmx (Jun 28, 2011)

WaterWheels said:


> If you had listed that you had swapped around sparkplugs then I would not have had to make the post I made, but at least maybe it could help someone in the future. Glad you have it running but what you say about the wires and your checking for spark does not make a lot of sense. How did you determine that spark was getting to the plug but then say you didn't understand how a brand new wire wasn't getting spark to the plug? Maybe it's just me. It sounds like the wire was either not seated well or there could be a problem with one of the connectors on the end of the wire.


I put in new plugs. The ignition wires new too. The cylinder that wasn't firing I pulled the plug on. In the process I shocked myself (wasn't thinking). After I pulled it off I used a volt meter an electricity was going through. I swapped some of the wires around seeing if it was the wires and a different cylinder didn't fire so the new wire must of had an issue, I don't understand how electricity was flowing through it but not getting to the plug.


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