Scantool readings

[omegax]

If you dont already know ive had some trouble with my car stalling out in neutral after a lenghty or hard drive. I hookedup vrg's scantool and here are the readings i got at idle, if anything looks off give me some suggestions.
Timing = 20
Airflow = 1.06-1.10v
TPS = 4.58v
Inje Pulse w = 2.048
IAC = 56%
Fuel trim jumps all around between 1.56 and -1.56%.
When i give it gass gradually it keeps going negative unless i slam the gas then it goes to 0%... i hope thats what it should be doing.
Timing correction 0%.. althouhg it flashes 21 ever few seconds.
Oxygen sensor = 0.1 - 0.67
Load 58-60 ( what is the load anyway)
Voltage 13.04 <- does that seem kinda low, when i throw on my foglights it even dips into the high 12v... range... could my alternator be dying on me?

[Legacy777]

I'm assuming that is a reading at idle with the car at NOT, correct? Also assuming you have a turbo correct? Correct me if I'm wrong.

Timing looks ok
Airflow looks ok
TPS looks ok.....it might be able to be adjusted slightly. Check out http://www.main.experiencetherave.com:8 ... sting3.jpg for info on testing & adjusting tps. Your idle switch may be off...might be an issue.
Assuming you have a turbo injectors look ok
IAC valve is a little high. If you have a turbo, it should be in the 30-45% range.
fuel trim or correction coeffiction is fine
timing correction or timing retard should be 0....and ranges from -10 to + 10 deg or at least that's what it should range according to the fsm.
load under idle for turbo should be 30-50 load is basically a calculated load on the engine which is derived by a formula which is based on the input of specific the engine sensors
Battery V is ok....should be between 13-14 at idle.

Verify turbo or non-turbo and whether the car was fully warmed up and at idle.

[omegax]

No turbo, its an NA manual tranny. It should have been warmed up since i drove to my friends house, then hooked it up and ran it again. Comparing it to the first time i did it i had the same readings and it was fully warmed up that time but i had a ghetto wire connection so i wanted to redo the test with a better wire.

[Legacy777]

what year is this?

[omegax]

Out of all the things ive changed , ive narrowed it down to the TPS or IAC ... both expensive parts but i am not sure if either is really at fault. It seems like something is getting stuck,the car stalls, and getting unstuck when i start the engine again. I' ve cleaned out the IAC assembly so i dont think it is that unless it is gone beyond repair. I also figured possibly the TPS is at fault but the voltage readings seemed correct even when the car stalled out.

[Legacy777]

if you can d/l the fsm pdf from my site
http://www.main.experiencetherave.com:8 ... ectrical)/ section 2.7 page 226 is where it starts.....you can check the numbers and info yourself.

[omegax]

91 legacy L MT non turbo

[vrg3]

That system voltage strikes me as a little low, but it's probably not the cause of your problems.

On 90-91 non-turbo 5MTs, the scantool can only resolve injector pulse width down to 2.048ms increments. "2.048 ms" could actually mean up to but not including 4.096 milliseconds. So I think that's alright.

And I believe you have a different kind of IAC valve from most of the rest of the BC/BF series of cars, so it's possible that your higher IAC duty cycle is normal. I don't know for sure though.

[Legacy777]

I'll try and take a look at my 90 fsm when I get home and see how your numbers compare.

[Legacy777]

Here's what the 90 fsm says the readings should be. I would assume they should be the same if not very very similar for the 91.

For MT at idle at NOT.

Timing: 18-22 deg
air flow: 0.8-1.2 V
TPS: 4.7-1.6 V (throttle change should be smooth)
Inj pulse w: 3.0-37 ms
IAC: 30-40 %
fuel trim: -1.6 - +1.6
Timing correction(rtd): -10 - +10 deg
oxygen sensor: 0-1.0 V
Load: 40-50
voltage: 12-14 V

Again....IAC valve is the main thing that is really out of spec. Injectors are lower....however mine are around 2 something at idle as well. So I wouldn't get worried.

I do however think it is a symptom...rather then the cause. unplug the connector for the IAC valve while the car is running and see what happens.

Your load value is pretty high as well. That may be ok if your idle is low.

[NemesisEJ22t]

I don't know if this is based upon the TPS reading solely, or if it even works for your NA, but on the last screen of the scan tool, right before it goes back to the ROM ID, check to see if your idle switch?? (or something like that, i think its the first one on the list) says "on" when your foot is off the gas. Maybe your car thinks its not idling and that makes it stall. Try to recreate the situation where the problem occurs when you use the scan tool and see what that gives you.

[omegax]

ill try to do that recreation isnt too big of a problem i can usualy redo the circumstances that make it stall or atleast drop very very low and shoot up, ill give that a shot and get back to you. If that is the case what would need to be replaced?
I wish i knew someone with another legacy to just swap parts with to test, it would make it much easier than buying a 250 dollars sensor

[omegax]

Also if this info helps at all, occasionally the idle will drop low to about 400 and stay there, I can rev the gas a few times till it goes away but sometimes it wont till I get going for a bit.

[Legacy777]

check the idle switch as mentioned.....if you have a DVM.....use the procedure I posted in the second post from the top to adjust/set the idle switch (which is in the TPS)

[NemesisEJ22t]

My guess is its the IAC valve, it may be sticking somehow, or, this is really out there, something with the PCV? Maybe the pcv has a leak in it and air is getting through it past the MAF sensor, causing a rich condition and stalling the car. The latter is really out there, but i would check the scan tool to see if it says the idle switch is on.