My idle and driving surging continues... I know my air meter is out of spec... but if unplugged shouldnt the car run?

If I diconnect the #2 plug from the ecu the car idles and revs fine with no surging... Runs really really rich like that of course... I know the AFM is on that plug.. but so is a bunch of other stuff... I tested the BAC valve the other day and it clicks and the resistance is .4 ohms over spec. Other than that my Switching Solenoid Valve is out of spec... but I dont think that can cause my problem...

Any more ideas?

 

Heck, man, maybe you got the same problem I have- how's your fuel rail pressures? Do you have a fuel pressure gauge? You can also determine how much fuel you're getting by looking at the O2 sensor outputs, but if you don't know how the readings look normally, you won't be able to figure out what's going on from the meter readings.

I guess by now you've read everything out from the ECU? Only thing that was screwy was the switching solenoid input? That would affect air pump flow, but I wouldn't think it would affect engine parameters, unless something's goofy with the ACV (you could always temporarily block it off for troubleshooting)...

There's no reason to pull plug #2 while running, especially if it all read out good earlier (except the one)...

 

I pulled the #2 and started it just to see if it would start and or run... I figured it wouldnt run seeing it wont with the AFM disconnected... but it does... so that also tells me that its not a vac leak.

I can test my pressures at work... but if that was the problem wouldnt it have the same problem with the ecu #2 unplugged?

I have not read everything from the ecu with it running... but I did do it with the ignition on engine warm.

I also already tried blocking off the ACV and the BAC air supplies... I also unplugged them from the harness... not a bit of difference. I also tested the scv resistance and tested it with power to make sure it was functioning, just as I did the BAC.

I really need to get an AFM... anyone have one they will part with for 20 bucks? I figure get that replaced just to be sure its not that.

 

I thought you got the AFM's inputs within specs by tweaking the spring? I'ts a simple voltage signal- as long as it's there, and it's within the ranges the ECU wants to see (compared to other scheduling inputs), it should be good. There's no "magic dust" involved here...Having said that, however, some guys have fixed problems by replacing the AFM...

This is deja-vu for me. I was at this point a couple of weeks ago while troubleshooting my problem- all the sensors looked good, yet the car was still acting up. That's when you start looking at the simpler systems, i.e. fuel delivery...

 

I didnt get the afm all the way in spec... I got it to about 2 volts... and it was getting really rough and stalled... I ended up putting it back to how it was to keep it from stalling so I can still drive it.

Voltage aside... how far open should the afm door be at an idle? if you measured the gap from the edge of the door to the wall of the afm, perpendicular to the air flow

I will still test the fuel system to be sure... but can you enlighten me as to how it would run fine with the #2 plug out of the ecu if the fuel system is not up to par?

 

Damnit, Jacob, you're proving Ted right after all, lol...

I have no idea how far the door is open at idle...Ummm...3 volts worth?

No enlightenment from me- it amazes me that she ran at all. I guess the ECU has the "fail safe" maps to keep her going when EVERY sensor goes to hell...

 

Yeah, I was just gonna sit on the sidelines and just mumble to myself...
I didn't want to mutter "I told you so" a million times...

I've never seen an airflow meter just go out of spec.
Unless it had been dropped, front end accident, or tampered with, it does not usually go bad.

There's a LOT of things that can trigger idle and hesitation problems.
The airflow meter should be one of the last things you should examine.


-Ted

 

LOL... well ether way the AFM is still out of spec (at 1.1-1.2 volts @ 1000 - 1500 rpm)

I am really at a loss as to where to go from here.

It has to be something electronic malfunctioning because of the fact that of unplugging it, it runs fine... well sorta fine... it runs without the problem.

What componets on the #2 Plug are prone to go bad or not function properly?

 

OK, why don't we just pretend for a moment that the AFM ISN'T out of spec, but your intake system IS...How about tweaking on the vac leak like you did the AFM, lol...

And you can't tell me one day that you've read everything out from the AFM, and it's all good (except switching), then come back with the question "What components on the #2 plug..."

 

LOL I think you mean read everything out of the ecu.. not the afm.. (reread what you wrote) but yeah I did.. I am just not sure what each component does for the car... and I was more or less looking for what components on that plug are most likely to go bad...