2g maf hz problems

[fst_4g63]

So Today I go out to the car to start trying to finish whats left,and I find that my hz are reading about 30-50hz thats it. Any Ideas on the problem It is a 2g in a 1g, the car is also chipped for the 2g maf(supposidly). Also other problems involving o2 reading especially low. Any help will be welcome thanks

Darren

 

[->PrOjEcTGS<-]

At idle?
Where are you getting the hz reading? From a logger or SAFC?
Where's the chip from?

Generally, if it's from Jeff O. at DSMchips he will burn the chip with double MAF hz logging capability. That means that you have to double the number the logger shows to get the correct value.

 

[fst_4g63]

The hz reading was from both my logger and safc, the chip was purchased from Chicago DSM a while ago. All readings were at idle I was trying to tune just the low trims so I can drive it to the shop.

Thanks again Darren

Ok well since there is no further input I am going to put the stock chip back in and see what happens. I will also replace the o2 sensor that may be bad.

 

[steve]

So Today I go out to the car to start trying to finish whats left,and I find that my hz are reading about 30-50hz thats it.

What does this mean?
Are you trying to say it never goes higher? Or that it's 30 to 50HZ during warmup?

 

[fst_4g63]

The car itself has not ran in 3 years, I went thru changing my ideas on what to do to it. First was a turbo swap and better tranny, then big turbo big fuel high horsepower,then I decided just to go budget sleeper. Court and other situation caused this,The car ran perfect before I started throwing parts at it.

The hz never move from full warm or from start-up. The hz and the o2 never adjust, I was told by a local guy to return the car to stock. This was to determine if the maf or the o2 was the problem. He believed the car is locked into open loop I believe.

Darren

All help is welcome

 

[steve]

The hz never move from full warm or from start-up. The hz and the o2 never adjust, I was told by a local guy to return the car to stock. This was to determine if the maf or the o2 was the problem. He believed the car is locked into open loop I believe.

MAF HZ have to change in relation to RPM. If yours doesn't change with the engine RPMs and throttle position then you have a hardware problem. Everything else the ECU does is largely in response to Airflow/Rev and that comes from the pulse rate from the MAF.

Your not so much "locked" in open loop as much as you fail to go closed loop.
On a 1G any of the following will keep the ECU from entering closed loop:

Throttle position too high (varies by RPM)
Airflow too low (units are tricky, but it's very low)
Coolant temp < 87F (109F on a 90)
The O2 sensor did not switch around 0.5v for over 20 seconds while running in closed loop mode.

Note than a non-responsive O2 sensor or too far off on your basic tune will keep the sensor from switching and cause the ECU to not run closed loop.

 

[fst_4g63]

Getting a new o2 sensor, I will be on it Quickly i will have a new o2 by sun down. Let's see where we get thanks .
Darren

 

[MuffinMan7580]

That's about what mine ran when I had a 2g MAS in my old car. As stated earlier though, it should change as rpm and throttle position increase.

 

[fst_4g63]

OK cool I only ordered the o2 to deal with the problem of the o2 not moving at idle. I figure this is what is causing the rich problem at idle. With that said I want to get it done right, I have done this more than once and don't want to do it again. This car has to make it to north carolina and I don't know what it's doing yet some keep the info coming thanks

Darren