[bcat]

To test MAF accuracy, I did a VE test (volumetric efficiency). Forscan with 3 PIDs. RPM, MAF grams/sec, and IAT. The O2 sensor is extra, just to make sure it's rich at WOT. This one looks good.

Then calculate VE. I used www.otctools.com/ve. A NA engine should be in the range of 75% to 85%. Mine calculated at 79%, which says my MAF is good enough. Maybe not perfect, but it's a cheap Ebay MAF.

The test requires WOT. I peaked at 6117 RPM in 1st gear. Maybe not a good idea if your timing belt is old. Attempt at your own risk.

 

[1turbofocus]

Only way to test WOT A/F is with a wide band air fuel gauge

Tom

 

[bcat]

Not what I was testing. As my frist four words said, MAF accuracy.

 

[1turbofocus]

The O2 sensor is extra, just to make sure it's rich at WOT.

This is what I was referring to ???

Tom

 

[bcat]

Purpose of O2 PID was verification of expected response. It's "extra," not a VE variable. For VE calculation I don't need A/F number. I'm not in the market for tuner services.

 

[1turbofocus]

Then why did you say " To make sure its rich at WOT "

The o2 does nothing at all at WOT on pre 2012

.93 Lambda on your o2 means there is something wrong some where

Not offering and never mentioned anything about Tuning

Tom

 

[bcat]

The o2 does nothing at all at WOT on pre 2012

Clearly it does, as Forscan shows.

.93 Lambda on your o2 means there is something wrong some where

At WOT it sees rich. As expected. Nothing wrong except your advice.

 

[1turbofocus]

What year Focus is this ?

.93 Lambda is 13.67 and in any year Focus thats WAY to lean , Rich would be 12.8 to 13

Even stock WOT Lambda is .85

Tom

 

[bcat]

This thread is posted in ZETEC Performance. That should answer your question.

 

[radius6]

Why do you keep posting here and then acting passive agressive against the people that reply?

 

[amc49]

Because he has no sense.

As said, he has not a clue. Anybody knowing how the computer works knows it disregards O2 readings when it goes to open loop, forscan is only reading what the open loop fuel has gone to and not rich enough as Tom said. Fuel in open loop is not controlled by O2; rather a preconceived fuel map since the engine has no wideband sensor in it. Somebody obviously missing the major difference in reporting and controlling a thing, and typical behavior for him.

The graph in post #1 clearly shows that but you have to be smart enough to interpret it correctly.

 

[bcat]

In psychology, "passive-aggression" is one of the most misused of psychological terms ... Culturally, the ambiguous "passive-aggressive" label is misused by lay persons and professionals alike.

https://en.wikipedia.org/wiki/Passive-aggressive_behavior

Plainly telling someone they're wrong is not "passive-aggressive."

 

[amc49]

That may be so but in this case I disagree, the diagnosis fits your general behavior to a T.

From your own link, which you have disregarded in certain parts to even now be guilty of said thing......

'Passive-aggressive behavior is characterized by a pattern of passive hostility and an avoidance of direct communication.[1][2] Inaction where some action is socially customary is a typical passive-aggressive strategy (showing up late for functions, staying silent when a response is expected).'

That's you or I ain't me. You endlessly post links as 'proof' but most of the time they blow your boat out of the water.

We understand your disdain for reality being it is so inhospitable to you.

 

[bcat]

The Mumbo Jumbo offered as knowledge here is spectacular.

 

[iminhell]

The Mumbo Jumbo offered as knowledge here is spectacular.

Isn't it though.
Some people have tools but no idea how to use them.

 

[iminhell]

MAF readings and some averaged (assumed) VE data for all (?) NA engines you looked up on the internet has no bearing on accuracy of some ebay MAF you bought because you spent all your money on tools you don't know how to use.

You want to test accuracy? (and you skill)
Put that sensor in a housing 8% smaller or 12% larger. Find out what happens. Look for trends.
Or you could change the location of the MAF you have now and look for changes.
Or you could actually put a good load on the engine and get better readings, *hint, 1st gear never loads and engine enough to get any meaningful data.


I totally get you're trying to learn. But you're arguing with people who know heaps of specific information and are trying to offer insight. You'd do well to shut up and listen.

 

[bcat]

MAF readings and some averaged (assumed) VE data for all (?) NA engines you looked up on the internet has no bearing on accuracy of some ebay MAF you bought because you spent all your money on tools you don't know how to use.

Proves my point.

 

[amc49]

Yes it does prove a point, just not yours.

In the context you just used there you just agreed with him.

Against your own self.

Again, the graph in post #1 clearly shows your post #8 as dead wrong. You won't know how of course.

 

[1turbofocus]

You guys are wasting your Time , he knows what he knows and acts like its Fact but its only what he thinks he knows , He wants to run his Engine that lean after being warned its SUPER LEAN then let him !

Tom