I'd just like a list of everything that would make it run very rich without tripping an ECU code... I'll start:

TPS out of adjustment
AFM out of adjustment
Injectors dirty/sticking
Vacuum leak

etc...

 

Your ecu, under default, would cause your motor to run rich If the Water temperture Sensor went bad. Than again, I'm told they rarely go bad. I bought a new one anyway, along with the rest of the Coolant Sensors last Summer.

 

Wouldn't that trip a code in the ECU though?

 

Yuppers.

 

Being stuck in warmup mode?

ScrapFC just went through this- couldn't pass smog- terrible HC

He started going through every system untill he found culprits- then he passed smog w/ AMAZINGLY good numbers.

PM him?

 

Fuel pressure regulator

 

I'm talking STRICTLY things that wouldn't throw a code.

 

Fuel filter and O2 sensor what caused my car guzzle gas like a viper. 8.7mpg I'm getting close to 18mpg after just replacing those two.

 

fuel filter?? why would the fuel filter cause you to run rich? If its clogged wouldnt it make you run lean?

 

I'm assuming the ecu compensates for the lack of fuel flow through the fuel filter by increasing fuel line pressure and injecting more fuel. But I could be wrong so don't take my word for it

 

If a fuel filter is clogged it will increase pressure...kinda like squeezing a garden hose......the orfice size is reduced so velocity must increase.

 

Well then... i guess that's my next bet

Thanks guys

****, every time i watch this video, i get misty eyed thinking how sweet it would be for mine to rev that quickly. But it's running so goddamn rich that it's bogging like a *****!!! http://www.vosko.net/media/rotary/t2revving.wmv

My S4 NA revved WAYYYYY faster. I gotta fix this rich fuel mixture or i'll shoot myself.

On the plus side, i found three vacuum leaks, all three contributed to the vacuum hoses on the front of the TB. That seemed to have fixed my buzzing acv issue... Now to make it run properly!

 

running rich isnt bad for an engine is it? i have a half bridgeported engine that is running very rich.

 

The above, can be applied to the Air Temperture Sensor aswell.

 

naw its not bad... just waste alot of power and carbon **** up. And it's unresponsive.

 

Fuel pressure regulator. Check your fuel rail pressure with the regulator under vac and pressure.

A clogged fuel filter isn't going to raise pressure.

Henrik

 

how do I check the fuel rail pressure?

 

It's there In both the FSM and the Haynes Manual. You will need a pressure Gauge tee'd Into the line. Specs are listed In their aswell.

 

explain

 

holy *****...........i love that rev......

is that with a stock fly wheel...........

mine bogs when i floor it (think the tb mod) but take off pretty fast like that........

 

'

Nope still buzzing seems to be temperature related.

 

How to check the rail pressure - its in the FSM

I think you mean the other comment though...

Lets look at the circuit first: pump is in the tank, outlet goes to fuel filter, which goes to injectors which goes to pressure regulator which goes back to tank. We also need to consider the effect that a "leak" (ie the injectors) introduces.

So think about your garden hose example where there is a constriction in the middle and the hose leaks after the constriction, pressure will rise on the inlet side of the constriction and the fluid velocity through the constriction will rise (as you stated), now it gets through the constriction, has more space and slows down again. Because the city (or fuel pump) has a max pressure on it, if the constriction is large enough (fuel filter clogged enough) it will hit this max pressure and flow will now start to be reduced. As you consume this flow through the leaks (injectors) the pressure will drop. If you consume more than can flow through the constriction (clogged fuel filter), then you start running out of fluid (run lean).

Since we're talking injection here, the only place the fuel pressure really matters is at the injectors.

BTW this is why the pressure regulator is at the end of the chain - it can only regulate the pressure "in front" of it.

Henrik