Finally! A good episode!

[Kit Sullivan]

Pleasantly surprised with today's episode. Some good diagnostic stuff, some good explanations about 'stoichiometric', O2 sensors, throttle body info...the kind of stuff they have always been good at.
And not a mention of double-sided tape, plastic trim pieces, decals, glitter paint, fake hood scoops, and thankfully...no turbo-diesel exhaust upgrades.
There was that pesky 'Tornado' commercial, but I know that will come off there sooner or later.
Keep it up, guys! I think some of your fans learned something useful today!

[Saltmine]

****! Why do I always manage to miss the good episodes?

Anybody know when it's going to be replayed?

[vetteonr]

Originally Posted by Saltmine

****! Why do I always manage to miss the good episodes?

Anybody know when it's going to be replayed?

Probably all week long.

[locobreath]

Agree that this was a very good episode, the kind of stuff that I really learn from... diagnostics and maintenance. I love the show, but I am getting tired of diesel electronic hopups and diesel exhaust systems and diesel engine brakes and yadda yadda yadda <g>.

However, I just watched it for the third time and I am astounded that Sam was talking about the air/fuel ratio as "percent oxygen". In the middle of the show, he mentioned that something to the effect that around 14 and a half "percent" was ideal. Then near the end, he explained that the meter only went to "22 percent", because pure air was only 21% oxygen and you couldn't do any better than that (I'm paraphrasing slightly but I think that's pretty close).

The meter plainly says "Air/Fuel Ratio", not "% oxygen". That means the ratio of the amount of air it takes to burn a similar mass of fuel, in equivalent mass units. The theortical ratio for complete combustion is 14.7 to 1 ( that's where the "stochiometric" combustion term comes in); i.e. 14.7 pounds of air are required to fully combust 1 pound of fuel.

Somehow Sam has apparently extrapolated this to mean that the O2 sensor should theoretically be reading 14.7% oxygen in the exhaust stream... I don't think so!

If I am wrong, I would love to hear an authoritative explanation.

[locobreath]

Another question... would love to have one of those throttle body swabs like McBride was using. I guess the manufacturer isn't a sponsor as I didn't see a brand logo or see in in the featured products. I've looked in all of the FLAPS but no luck finding same.

Anybody know a source (BigBry?)?

I believe the guys used a swab like that before. As I recall it was a show about cleaning the intake system. Not sure but I think it was part of the product they were selling. I'm sure someone will remember.

I liked this show. I did learn some things. Thanks Guys.

OKOKOK.... I found it.

http://www.run-rite.com/industry/products01g.htm

It's the Intake Snake Tool #9710 and Heads #1310 from TGG Epsiode #301 - Fuel System Diagnostics

[locobreath]

I believe you are correct, sir... may have been under a C&C or even STM title. Didn't they do one where they injected some sort of intake passage cleaner that worked while the engine was running?

The old STM did one using the 3M cleaning system, but I believe there was another product that was shown on another episode.... that's the one I am thinking about. Might have been the one with the swab.

Thanks for the link... excellent!

[FieroSpeeder]

Originally Posted by locobreath

......

i think i saw that episode but not this week.



air only has around 21-22% of oxygen, someone more anally will get the exact percentage

air fuel ratio is plain air vs the ratio of fuel so 14.7 parts of air to one part of fuel.


The oxygen sensor reads the left over of oxygen in the fuel compared to atmosphere oxygen. .5 volts is close to stioch but it isn't exact because the scale is very bad therefore, you need a wide band o2 sensor or a gas analyzer.

[Kit Sullivan]

Actually, air is made up of 19% oxygen, 80% nitrogen and 1% other various gasses.

[locobreath]

According to my copy of "Internal Combustion Engines and Air Pollution" (Obert), pure, dry air has the following composition (by volume):

Oxygen: 20.99% (**** close to 21% ! )
Nitrogen 78.03%
Argon 0.94%
CO2 0.03%
Hydrogen 0.01%
______
100.00%

[locobreath]

>>The oxygen sensor reads the left over of oxygen in the fuel compared to atmosphere >>oxygen. .5 volts is close to stioch but it isn't exact because the scale is very bad >>therefore, you need a wide band o2 sensor or a gas analyzer

Agree with your statement, but my point was that 14.7 RATIO was the ideal, not 14.7 percent.

[schretter.works]

It was a repeat from a few months ago.

[danny]

Originally Posted by schretter.works

It was a repeat from a few months ago.

shhhhh-he's just starting to be positive, let's keep it going

[Kit Sullivan]

Hey Danny,
I would much rather see repeats of quality, well-produced and useful episodes than brand-new episode featuring yet another diesel truck exhaust upgrade, peppered with commercials for products with dubious(to put it kindly) value.

[danny]

Originally Posted by Kit Sullivan

Hey Danny,
I would much rather see repeats of quality, well-produced and useful episodes than brand-new episode featuring yet another diesel truck exhaust upgrade, peppered with commercials for products with dubious(to put it kindly) value.

of this i agree whole heartedly.