I hate to share this as it made me look like a genius one time,,after engine cold,, when you check for bad plug misfire run engine for 45 seconds to one minute now check for the cylinder that is coolest.. the cylinders running properly will be hOOter than misfire cylinder .to check for worst cylinder with mechanical problem run 30 seconds effeects of leaking valves can negate this test,,to look like intellectual diagnostician do not touch cylinder just move finger close to manifold pipe as you move thru all cylinders ha ha works best on 4,, then pull plug and ground and check NEVER hold plug wire and allow to jump to block,this is harmful to system (can,t remember why) always have spark plug in cap when engine fires

This is a joke right?

quote Originally posted by p8ntman442: This is a joke right?

there you go again.

he's trying to be helpful
it's a simple trick that some people have never thought of, or seen before
i've also touched the pipes on motorcycles to track down which carb was messed up.

edit to add that i've never heard letting the spark jump through the air will hurt the system.
just as long as it really does spark where you want it to and not back on the coil.

[This message has been edited by buddycraigg (edited 09-21-2007).]

The best tool to use for this is the laser infared thermometer. Just point it at each of the exhaust ports. Craftsman tools $59.99.

Handy for many things. Like checking to see how mad I've made my sweet bride!

you can get the IR "laser" thermometers at Harbor Freight for $29.99 works great.

I really like the temperature trick and it makes perfect sense! Thwack to my forehead for thinking of it on my own.

thanks for sharing this tip!

[This message has been edited by timgray (edited 09-21-2007).]

quote Originally posted by timgray: you can get the IR "laser" thermometers at Harbor Freight for $29.99

I paid $6.99 for mine at Harbor Freight. You just have to wait for them to be "on sale."

[This message has been edited by Marvin McInnis (edited 09-22-2007).]

quote Originally posted by Marvin McInnis: I paid $6.99 for mine at HF. You just have to wait for them to be "on sale."

PM me when you see that sale again.

I just thought of a brilliant way to check which plug wire isn't firing.

this should be filed under poor maintenance techniques. Changing spark plugs takes less than 30 minutes and cost less than 15 bucks. If you have a missfire, and want to diagnose which cyl it is, jump Pins A and B on the aldl connector, and then start the car. This will hold it at 1000 RPM. Now pull plug wires off the dist cap one at a time. Whichever dosent make a difference is the culprit.

Neither requires you to put your hand (a calibrated tool ;-{ ) on a hot exhaust manifold to feel which is hotter.

There are many ways to skin a cat. There is usually a better way to do something. I read that post and replied before looking at the username of the poster. So dont tell me Im going after the guy.

Here's a little news flash for you.

The human finger touch can discern differences it takes thousands of dollars of test equipment to identify, and we all already have one! The hand is a calibrated tool and if you don't use it, then you lose. The example given by the poster wasn't just for spark plugs. Any misfire can be identified that way so it's not just poor maintenance.

As far as your method, let me see..........

Do I run the motor for 30 seconds, shut it off, pass my fingers closely over the manifold with the engine off OR
Take off the cover in the console, jumper the aldl, start the engine, walk to the back, pull each high voltage plug wire off the distributor (which, btw, you'd best have a good pair of insulated plug wire pliers to do), while the engine is running?

I'll take the first method. It's faster. Easier. No tools required. And yes, you CAN damage the electronic ignition by pulling plug wires off. It doesn't happen often, but it can happen.

John Stricker

quote Originally posted by p8ntman442: this should be filed under poor maintenance techniques. Changing spark plugs takes less than 30 minutes and cost less than 15 bucks. If you have a missfire, and want to diagnose which cyl it is, jump Pins A and B on the aldl connector, and then start the car. This will hold it at 1000 RPM. Now pull plug wires off the dist cap one at a time. Whichever dosent make a difference is the culprit. Neither requires you to put your hand (a calibrated tool ;-{ ) on a hot exhaust manifold to feel which is hotter. There are many ways to skin a cat. There is usually a better way to do something. I read that post and replied before looking at the username of the poster. So dont tell me Im going after the guy.

I bet you guys have GEICO...............

NO joke ,, this a tech tip that works,I was a scooter mechanic when I was not working security,this tip was obvious to me when I worked on a honda 4,,this is tip that recently used why the post.. I checked engine for work associate,pop hood he ran engine for 1 minute, I just ran index finger close to manifold(had manifold cover) at head 4 male co workers were observing when i pronounce that it is #3 cylinder,and only a new plug was needed(lucky guess, based on experience) this is a tip that will save time and money My post are simple,,aimed at the novice or person with limited skill . I post on subjects I know about from my 20 years experience as a scooter mechanic,,also going to peoples homes and helping them repair thier bikes and cars..I swapped my first engine in 1955,olds V 8 into1949 ford,I have worked as an auto mechanic,worked in paint and body shop.. I owned my first fiero in the early 90s,an 88 GT with a duke?? I have recieve thank you,s in my e mail and on the forum,,many experienced people do not like my post ,, the tip about not holding the wire so it jumps to the head is based on info from experts,, also many people have to try for large spark gap jump and find the spark jumps to thier hand!! some new cars have a shock that will put you on the floor!! perfectly O.K. if some one questions my post keeps me on my toes..THIS WORKS especially for the inexperienced,,some day i will post 50 tips to help novice... po8ntman you will love this one ..afterthought I was a real pointman with USMC 5 years = 0311, 0811 "1994368" sgt newton(airborne) 1/9 10th marines,, 12th marines and anglico!! weapons and tactics instructor 1st infantry training regiment,a green hat just below drill instrutor

[This message has been edited by uhlanstan (edited 09-22-2007).]

No, I don't.

Don't see what that has to do with anything, but I guess thanks for asking.

John Stricker

quote Originally posted by p8ntman442: I bet you guys have GEICO...............

I'm in "uhlanstan"'s corner. Some things can be diagnosed with low technology. For example...

Back in THE day when I was a kid I watched several old timers balance a front tire on a 53 Chrysler. Of course there were no computers.
They jacked the front wheel off the ground, , removed the old weights and then played former day version of "Wheel of Fortune"
When the wheel came to a stop it would then swing back in the oposite direction and repeat this on its own until it came to a rest.

At this point the heavy part of the tire would be at 6 o'clock. They would tack on some weight at 12 o'clock and spin again.

If their weight-guess was right the wheel would stop without rolling back in the opposite direction. "BingO" / wheel balanced.

Bear in mind that these wheels had "Ball" bearings not roller tappered bearings , the brakes were not self-adjusting meaning no drag on the drum and the tires were bias ply.

Can't get any simpler than that..

Spoon

SPOON you are genius reminded me of tip for those who want smooth gigalo paris boulevard ride ..you can jack car up or do this any time you you remove tire ..if you spin tire close to floor you see high spots you can try different holes and find location with least up and down ..also you can loosen lugs and reajust to get most concentric tire roll this is just a trick for those who want perfection I do it to all my wheels this is mostly for people who drive on good roads ,perfectionist,, and mostly interstate drivers

I'd be a little hesitant of THAT method, but I have and use a bubble balancer.



Something under $45 at harbor freight on sale, and with my 15% flyer coupon. I've balanced wheels and taken them to have checked on a spin balancer and they've never needed more than 1/4 oz of weight difference (and I'm not sure it NEEDED that, I don't know what the tolerances of the spin machine are.) Never had anyone come back with a vibration and I've fixed vibrations on vehicles that had been to a spin balancer.

John Stricker

quote Originally posted by Spoon: I'm in "uhlanstan"'s corner. Some things can be diagnosed with low technology. For example... Back in THE day when I was a kid I watched several old timers balance a front tire on a 53 Chrysler. Of course there were no computers. They jacked the front wheel off the ground, , removed the old weights and then played former day version of "Wheel of Fortune" When the wheel came to a stop it would then swing back in the oposite direction and repeat this on its own until it came to a rest. At this point the heavy part of the tire would be at 6 o'clock. They would tack on some weight at 12 o'clock and spin again. If their weight-guess was right the wheel would stop without rolling back in the opposite direction. "BingO" / wheel balanced. Bear in mind that these wheels had "Ball" bearings not roller tappered bearings , the brakes were not self-adjusting meaning no drag on the drum and the tires were bias ply. Can't get any simpler than that.. Spoon

So the guy with a 4 cyl had a bad plug on # 3. So now what, change all 4 plugs right? unless your gonna mismatch plugs................

Wrong!! this will not balance tire it makes the tire and rim more concentric..if rims are good it will improve ride does not improve balance.. I sometimes dismount bead and realign tire to rim..if you check your tire,have tire1/2 inch above floor and spin tire.. you will see the tire is not centered,you can see the tire move to 1/4 inch and 3/4 inch or more ..you want your tire to roll concentric .. the tire that rolls true makes for a better ride this is to much work for some people but it is the small things that create the most power in an engine,, the small things that create the best ride attention to detail..in the late 60s I built ducati 250s that would smoke 2 strokes by attention to the small things in my present 86 gt project,,,just running and shifting is the goal once this is accomplished I will pay attention to detail,,28mpg around town is my goal with V6 with 20 more horse power