TheSamba.com :: View topic - how do you know if your running on three cylinders???

Sun Mar 14, 2010 11:47 am

I think i might be missing a cylinder. but how o i know?

Sun Mar 14, 2010 11:49 am

Pull the plug wires off of the distrubutor 1 at a time while it's running and listen for the rpm drop. If the rpm drops for each wire then you are hitting on all 4, if not the one that doesn't change isn't firing.

Sun Mar 14, 2010 12:39 pm

I remember once, somehow a plug wire came off and I drove like 5 miles on the freeway and something didnt feel right but it was not a big deal until I drove up a steep hill and then I knew something was really wrong.

Sun Mar 14, 2010 1:08 pm

Sometimes you can get a false read at an idle. If you are in doubt try it again around 2K RPM's.

Sun Mar 14, 2010 1:30 pm

Quote: Pull the plug wires off of the distrubutor 1 at a time while it's running

yeah, right buddy. you go ahead. I'll watch.

ignition off
pull one spark plug wire
start engine
ignition off...

Sun Mar 14, 2010 1:49 pm

Mal evolent wrote: Quote: Pull the plug wires off of the distrubutor 1 at a time while it's running

yeah, right buddy. you go ahead. I'll watch.

ignition off
pull one spark plug wire
start engine
ignition off...

That takes too long, and if you have subtle missfire you might miss the RPM difference. You can use rubber handled pliers or spark plug pliers if you are scared.

Sun Mar 14, 2010 2:51 pm

A friend of mine once told me a ACVW motor is a 2 cylinder with the other 2 thrown in for balance :D

Casey

Sun Mar 14, 2010 2:54 pm

Quote: if you are scared.

make that experienced.

high voltage causes a permanent cardiac condition known as disrythmia. old time electronics techs from the vacuum tube days all have it, because we all got nailed by B+. no reason to worry about smoking if you have dysrythmia. old age ain't happening.

Sun Mar 14, 2010 3:25 pm

Mal evolent wrote: Quote: if you are scared.

make that experienced.

high voltage causes a permanent cardiac condition known as disrythmia. old time electronics techs from the vacuum tube days all have it, because we all got nailed by B+. no reason to worry about smoking if you have dysrythmia. old age ain't happening.

I have taken 18,000 volt from the B+ @150ma on a 3000watt industrial laser. That was in 1984. I am still moving around almost 30 years later. And mine went through my heart.
I have been bit by spark plug wires many times in the last 50 years.

Sun Mar 14, 2010 3:39 pm

Mal evolent wrote: Quote: Pull the plug wires off of the distrubutor 1 at a time while it's running

yeah, right buddy. you go ahead. I'll watch.

:lol: :lol: :lol:

I laughed out loud! I too, share your respect of the coil! I use rubber gloves and pliers...

Sun Mar 14, 2010 6:45 pm

get an empty windex bottle and fill it with water. with the engine running, spray a bit of water on the header pipes near each exhaust port.

no sizzle, no spark......

Sun Mar 14, 2010 6:52 pm

or a six pack of beer...

Sun Mar 14, 2010 6:59 pm

[quote="Russ Wolfe"] Mal evolent wrote: Quote: if you are scared.

make that experienced.

I have taken 18,000 volt from the B+ @150ma on a 3000watt industrial laser. That was in 1984. I am still moving around almost 30 years later. And mine went through my heart.
I have been bit by spark plug wires many times in the last 50 years.

dude, if you have taken this kind of hit repeatedly.... you might try something different... :wink:

Sun Mar 14, 2010 8:06 pm

[quote="STOICH"] Russ Wolfe wrote: Mal evolent wrote: Quote: if you are scared.

make that experienced.

I have taken 18,000 volt from the B+ @150ma on a 3000watt industrial laser. That was in 1984. I am still moving around almost 30 years later. And mine went through my heart.
I have been bit by spark plug wires many times in the last 50 years.

dude, if you have taken this kind of hit repeatedly.... you might try something different... :wink:

Well, id did send me to the ER. Blood pressure was like 270/150. ER was surprised I was still alive.
Nurse asked me what it felt like. I told her "It did not knock it stiff"

Sun Mar 14, 2010 9:08 pm

if you pull htem from the dizzy you will not get shocked, and if you do it will only be once. if your not too bright and pull em from the spark plug end you'll probably get shocked 30 times before you get it back on. stock ignition aint got much kick, but enough if you are not expecting it it can make ya jump.
now vanagons, thats another story, those transistors help her bite ya.

Sun Mar 14, 2010 9:32 pm

bajaherbie wrote: get an empty windex bottle and fill it with water. with the engine running, spray a bit of water on the header pipes near each exhaust port.

no sizzle, no spark......

This is the smartest way and best way to know for sure if any cylinder is not working.

the dumbest one is licking it...but works too. :lol:

Sun Mar 14, 2010 9:39 pm

im gonna check all these methods tomorow.

Mon Mar 15, 2010 2:58 pm

I have a similar issue. I have a new 1915cc motor. When I pull the wires off the spark plugs on either cylinder 2 or 4 it does't even change the idle 1% When I do the same to either 1 and 3 boom she dies.,

What should I do?

Mon Mar 15, 2010 3:45 pm

If you have dual carbs, you just about need a balance pipe between the 2 sides.
This will smooth the idle out 90% of the time.

Mon Mar 15, 2010 4:27 pm

For a number of reasons at IDLE..yes

But for the life of me, how can you drive it on the road and NOT
detect that it's running like a pig with his leg chopped off! ?????
I guess I don't get it ?