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Discussion Starter · #1 ·
Ok, for some reason I have it in my head that one of my cylinders isn't working. 10-1 odds this is me being stupid. Its just something about the sound of the car when its cold...I have absolutely NO OBJECTIVE EVIDENCE THERE IS ANYTHING WRONG. But as these things go, its been eating into me, and I asked myself how I could check that easily....

So I took the cover off my distributor (the thing that simply holds the wires in place) and figured I would have the engine at idle and just pull them one at a time and see how the engine sounds with one less cylinder...If one of them made no diffrerence, then viola! we have an answer.

Well, I pulled off #1 and got slightly shocked by the arc...No surprise there...I said this is me being stupid. And thought I heard NO DIFFERENCE. because of the shock, I got spooked that I was doing something stupid (I am sure I was) and put it back on...and the engine sounded slightly better...so probably there WAS a difference, but having gotten shocked, I didn't really notice it.

As I said, I got worried I was doing a total no-no....so I aborted the test and figured I would come here to let you guys tell me if that is stupid (I bet), if I could have done anything bad to the engine (I doubt) and if there is a simpler way of doing this type of test to see if each cylinder is firing properly.

Yes, I plan to feel very silly...so go ahead and tell it like it is!

Michael
 

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X2 on checking the plugs. Look closely at the suspected bad plug, it is very possible the porcelian is cracked. My new motor came with a bad plug, the porcelian insulator had broken off the base of the plug and was resting on the ground electrode. Change the plug and try it. If that does not cure it might be the plug wire, try another one and if the problem still persists a compression test might be in order.
HTH
CB
 

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Really easy check - see if all the header pipes are hot. If one isn't, that cylinder isn't firing.

I recently changed my plug wires and after I finished, it was running but just didn't sound right. I checked the wires again and figured out I had #7 and #8 swapped :blush:

Pete
 

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get one of these from HF and check each header pipe about 3 inches from the head.

 

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The computer in your MassFlo system will carry out what is known as a Cylinder Balance Check if you know how to run the codes. It basically shuts down one injector at a time to see if there is a change in rpm (no change = not firing).

http://www.tomco-inc.com/Tech_Tips/ttt6.pdf

Cheers, Rod
 

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I have not had to check for misses in quite awhile, but in the past what works for me is to take your timing light, hook it up and then move the plug pickup around from plug wire to plug wire and watch the strobe. It will at least keep you from getting shocked initially.

Steve
 

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KISS principal

Mirose:

High technology is great and all the above methods work, but so does a spray bottle with water in it. If you suspect that one cylinder is not firing, poof some water on the header pipe and see if it instantly vaporizes or stays wet for a while. The timing light will tell you if a plug is not firing intermittently as you go from one wire to the next by not firing in a regular pulse. As you have already found out, pulling plug wires on a running engine is a good way to learn how to fly.

Ron
 

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Pulling the plug wires from the cap one at a time and checking for load changes is not going to harm anything, but you do need a nice pair of insulated wire pullers. They prevent you from getting shocked and the end grips the wire/boot without damaging it. I've used this very method for decades on EFI and carb'd cars to check for weak/dead cylinders.

Try it again, one at a time, with the right tool, and you won't get the crap shocked out of you! :yes:

HTH...
Mark
 

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x2 on the spray bottle idea - I use that on my 4cyl honda all the time. For years I thought it was just clunky, then found that 3 of the idle jets were blocked solid.

It's amazing how well a Honda will run on 1 cylinder :001_tongue:
 

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pulling the wires off while the car is running can really mess up you exhaust bearings and gears. Your also lucky you did not get a flat tire. :)
 

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The computer in your MassFlo system will carry out what is known as a Cylinder Balance Check if you know how to run the codes. It basically shuts down one injector at a time to see if there is a change in rpm (no change = not firing).

http://www.tomco-inc.com/Tech_Tips/ttt6.pdf

Cheers, Rod
Ford built this into the EEC and it works really well, give it a try. You just need to make a jumper from 3" of wire and two male spade connectors. You don't need a code reader doohicky if you have a check engine light hooked. Simple and virtually free.
 

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TJ, that was a joke. I know it was hard to tell with that one (sorry QSL) but the yellow thing at the end smiling usually denotes a joke was implied, even if it is not funny or you don't get it... :D

Mark
 

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pulling the wires off while the car is running can really mess up you exhaust bearings and gears. Your also lucky you did not get a flat tire. :)
Those exhaust bearings will get you every time. That and the blinker fluid.

-Kyle
 

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The scary part

Here's the scary part - QSL was being serious!! :evil:
 

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Discussion Starter · #19 ·
Thanks for all the advice, guys. I especially love QSL's attempt at humor. I always thought it was the Fetzer Valve was most a risk when doing this kind of thing to the engine. But what do I know?:evil:

I am going to check out a few things when I get a chance.

-Michael
 

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Originally Posted by QSL
pulling the wires off while the car is running can really mess up you exhaust bearings and gears. Your also lucky you did not get a flat tire.

TJ: ya lost me there....


TJ, that was a joke. I know it was hard to tell with that one (sorry QSL) but the yellow thing at the end smiling usually denotes a joke was implied, even if it is not funny or you don't get it... :D

Mark

Classic lines from "The Expendables"

Randy Couture: You lost me there.

Terry Crews: When Omya's prime is struck, she give off a miniature warhead that arms itself. And when that happens, anything that gets in my lady's way becomes instant red sauce and Jell-O. And if that doesn't work... [holds up a razor with "Caesar" engraved on it] Her sister will.

Randy Couture: You should meet my doctor. :evil:
 
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