1st question
Can a misfiring /dead cylinder cause noticeable enough vibration in the car, in neutral and while driving?
(I just want to make sure; I also have a lack of power so I’m guessing that’s my dead giveaway)

Second question
What the best way to determine above dead cylinder?
Disconnecting plug wires?
Disconnecting injector wires?
Checking header temperatures?
Any other way not mentioned?

The vibration started out of the blue and is present both cold and hot.
I changed my plugs and made sure my wires were on tight but the problem is still there. My wires are fairly new MSD 8.8's, less than six months.

I also checked my timing and it is at 8 deg BTC. I know my car calls for 6 deg, would that make much of a difference?

 

1st. question. Yes, a misfire will induce a noticeable vibration, and lack of power, less noticeable at higher RPM.

2nd question. Disconnecting injectors/plug wires one cylinder at a time (whichever is easier...... just watch out on the plug wires....) and see which one does not make a difference. There is your dead cylinder. Once you know which one it is, then you need to find out WHY...

Have fun........

 

2. If you have headers, let them cool all the way down; start the car, and let it run for about 10 seconds; shut it off, and dribble a few drops of water on each header tube, like with a squirt bottle or something. It won't be hard to figure out from there.

 

Man, that hurts. Not once, but three times.

Anyway, thanks for the responses. As you can tell, I did the plug method.

I had to ask because I didn't know what to expect but it is really obvious.

Anyway, as my luck would have it, it's #8 that's missing.

From what I checked, the spark is jumping from the cap to the plug wire. I didn't check the wire to the plug yet because I didn't want third degree burns. I used a screwdriver to listen to the injector and it sounds like it's firing but I want to use a noid to be sure.

Now, since this started before I changed my plugs, I can rule out my plug no?

Is it possible to get a spark at the cap and not at the plug?
Meaning, if my wire was bad, would a spark still jump from the cap to the wire?

Thanks again.

PS Looking back, I should have used RB83L69's method.

 

You can place a finger on the back of an injector and feel it click or pulse it should be quick and rapid as the others you can compare, The injectors are batch fire.
Since the problem has continued from the plug change yes you can rule out the plugs but what about the condition of the cap and cap to rotor contact for that cylinder , that needs to be checked as well.

Another way to check your spark on the end of each spark plug wire would be to unclip the fuel pump relay switch its located on the drivers side on the fire wall between the brake booster and the drivers side fender. You can start with a cold car unplug one of the relays (there are 3 in a row there) and turn your ignition key to on and listen for your fuel pump to prime if it primes try a different one but wait at least a minute between tries. Once you find the correct one you can spin your motor as much as you want and check all of your wires for spark with out ever firing a cylinder and getting burned.

 

Yes, in fact there is another thread going right now where someone has a spark jumping from the boot to the header. Sometimes it will arc down the body of the spark plug to the block (on older plugs). Electricity will take the path of least resistance. If your wires sat on the headers and cracked from the heat or burned and cracked, you could be arcing right through there. Lots of possibilities.

And yes, RB tends to have some neat old tricks. Did I mention old?

 

Hey! I resemble that remark

That's my next step since it's easy but if that was bad, would I still get a spark from the cap to the wire? Thats where I disconnected everything and I got a nice spark to jump from the cap.

Thanks again.

Scott

 

no if it was bad there it would not make it out of the cap...