Did I mess anything up?

[mirose]

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

[NHolds]

You didn't do any damage, but just check the plugs.

[Cone Basher]

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

[PSB]

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

Pete

[Erik W. Treves]

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

[dv/dt]

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

[Steve1979]

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

[ROADRACER83]

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

[bbk347]

Old drag racing trick is to draw a line on the header pipe with a crayon. The one that doesn't melt off isn't firing.

[Mustang Man]

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!

HTH...
Mark

[rockpool]

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

[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.

[tjmotter]

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.

ya lost me there....

[MJN]

Originally Posted by dv/dt

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.

[Mustang Man]

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...

Mark

[tjmotter]

Originally Posted by Mustang Man

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...

Mark

I figured it for a joke but just not gettin it Must be a warped sense of humor on one of our parts...

[kgkeys]

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.

Those exhaust bearings will get you every time. That and the blinker fluid.

-Kyle

[Pedalmasher]

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

[mirose]

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?

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

-Michael

[tjmotter]

Originally Posted by Mustang Man

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...

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.

[QSL]

Tough crowd here!

Mirose, talking about shock... when we first started the engine we had our coil zip tied to the 1x1 bars that go under the front fenders of the body but the body was off. I had a wrong coil wire on there with the wrong boot on it... ie exposed. While trying to "tune" the engine i was leaning over it.... Who would know all the fat in my stomach conducted electricity so well? Felt pretty good for the first three times, but then figured i should fix it.

[CraigS]

Not sure how your dist cap is held to the body, but be careful pulling the wires out that you don't shift the cap any. If the rotor hits the contact in the cap, both will be ruined.

[pefflyem]

I think it is a bad muffler spring or bad air spring or may a bad right rear tire injector.?
Do not get lost, there is a company on the net that has replacement parts for all these problems.

As above no heat on the exhaust means on fire.

[Dr Stebo]

Another cheap way of doing a cylinder balance test is with using 8 equal lengths of vacuum hose that will slip over the terminal on the cap or the coils depending on if distributor or distributorless. Cut each about an inch long and slip a piece over each plug terminal on cap. Then slide plug wire over so hose is between cap and terminal. Start engine and there should be enough carbon in hose to let it run. Now with a test light that is connected to a good ground, one by one use the probe end until you get close enough for spark to jump. If engine sound changes then most likely that cylinder is not the culprit. Go around distributor slowly until you find a cylinder that there is little or no change in rpm.

[mirose]

Originally Posted by QSL

Tough crowd here!

Mirose, talking about shock... when we first started the engine we had our coil zip tied to the 1x1 bars that go under the front fenders of the body but the body was off. I had a wrong coil wire on there with the wrong boot on it... ie exposed. While trying to "tune" the engine i was leaning over it.... Who would know all the fat in my stomach conducted electricity so well? Felt pretty good for the first three times, but then figured i should fix it.

This is actually pretty funny because I was once operating on a patient who had one of those implantable defibrilators...and you have the rep from the company turn the defibrilator off during the operation because the cauterizer pen that we use in the O.R. can fool the defibrilator to shock the patient. Now the patient is asleep, but the surgeon isn't...and its really too protect the doctor from getting shocked because even though we wear rubber gloves, outr bellies are pressed up against the patient most of the case and all we have between us are cloth and paper garments. Neither of which do a great job of insulating...as you will see.

Now I had the rep turn the device off, but about ten minutes into the case I suddenly got thrown back about 2 feet and it took me a minute to realize what had happened...the device had a faulty switch and despite us thinking it was off, it really wasn't...and both me and the patient got shocked, just like in the movies when they scream "CLEAR!!!!!" and then shock the patient. Fortunately for the patient, he was asleep and didn't feel a thing...Me on the other hand, not so much.

So the bottom line is, Yes, the belly DOES conduct electricity. Quite well I might add.

Cheers! -Michael

[dv/dt]

Just be thankful you are not taller!

[mirose]

Originally Posted by dv/dt

Just be thankful you are not taller!

Didn't think of that...very funny.