Idle surges MAP sensor volt surges falls on face from 75% throttle 2 full throttle

[steveo]

look for some clues,

what's the o2 voltage when it falls on its face? steady high or low?

a severe ignition miss or a fuel starvation issue usually throws your narrowband o2 lean at WOT (normally narrowband should pretty much always be rich at full throttle)

you've been playing with your TPS, does it get a decent voltage at full throttle?

what's your MAP at heavy throttle like that? should be pegged at about barometric pressure, i'd hope, but is it solid or does it fluctuate?

if you post a datalog maybe someone will have some other ideas

[ChrisBama]

Thanks, I will get more info posted today. I didn't know what where to check at this point.
I was going to try to datalog today but cant get my laptop/WinALDL to see the WinALDL to usb cable? Do I need an interface between them?
Is there a better software than WinALDL? It is looking for com1 and I can't find a usb option?
Thanks for Your help, Any info is appreciated.

[stew86MCSS396]

Are you getting any cel codes? That would be a good place to start. Whether you’re using winaldl or tprt, either will be able to retrieve the codes or you could do the paper clip method.

[ChrisBama]

I never did get my laptop to see the usb ALDL cable? My scanner adds aprox. 250 rpms while checking codes and viewing the data stream, is that normal?
My scanner requires a serial cable to hook up to the computer or printer. I don't own a computer with serial hookup anymore.

What are the setting values and what are there ranges that my bin is looking for?

The o2 voltage goes from the 200's to the 400's to the 800's and bounces back and forth and jumps between them. That's all the time driving or at an idle.

The always rich as You said is why I ask if the IAC always at 145 parked in gear meant it wanted more air? which could be the code 45 rich?

TPS, does it get a decent voltage at full throttle? solid 4.75 same driving as when the engine is not running and You floor it. How does the TPS effect the way it runs?
My understanding is it doesn't effect air/fuel, so what does it do? I ask after already playing with it lol and didn't learn anything. lol

MAP at heavy throttle? 3.65-3.76

The other code is the VSS vehicle speed sensor.

So, what are the value ranges that my bin is looking for?
Thanks Chris

[stew86MCSS396]

10k resistor between a-b on aldl when hooking up scanner will send ECM into aldl mode which adds about 10 degrees spark and rpms goes to a 1000.

[sturgillbd]

Take the "B" pin out of the ALDL connector under the dash. Seems like some cables put 10K across the A and B terminals and don't have a switch to disable it. Back the pin out and see what happens.

Brian

[ChrisBama]

That makes sense. My usb to ALDL cable has a 10k jumper pin.