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Getting angry with car stalling

deez

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May 29, 2004
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Chico, CA
I took a bunch of readings now that my logger works /ubbthreads/images/graemlins/smile.gif Maybe someone can tell me if they mean anything.

ISC reading varies from 13-15, VSPD is bouncing around which I don't know what its supposed to do when sitting still, voltage at idle is 13.9-14.0, O2-R is bouncing from .05V to .82V and everywhere in between, TPS at idle is 10.5%, vacuum at idle is about 13" (keep in mind cams), voltage at idle with ac on is 13.7 and with lights also 12.9v, and car just dies when revved with ac and/or lights on at stop. And now I am looking at the VSPD with the car off but acc. on and its still bouncing around, which seems odd. And the pulley is stock.
 

KGVR4

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Sep 19, 2004
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1,324
Location
Bellevue WA
Do your lights flicker/get dim?
 

deez

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May 29, 2004
Messages
1,150
Location
Chico, CA
no they dont
 

VSPD doesn't work on our cars. The only way to see what the speed sensor is doing is to add address C6 to an open logger address, if you have a version of MMcD that allows that.
Everything else sounds fine, I have no idea why your tune has changed. Liquid filled gauges DO change greatly with temperature. Just ignore the reading, and tune the AFPR to get a HIGH TRIM of 100.
 

deez

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Thanks Jeff. Here's a question....if I added fuel at idle to get it from the 160 range from 3% to 9% and saw no change, doesn't that seem like something is wrong?
Before I zero out the safc and dial in the trims, I would like to address why the car stalls with the accessories such as lights and ac on more so than without. That seems like a variable unrelated to trims. It doesn't even try to catch itself sometimes, yet sometimes it catches itself. That seems like something else. And the code 22 for the CAS has not reappeared after two days of driving, so I guess that was a fluke.
 

Quote:
if I added fuel at idle to get it from the 160 range from 3% to 9% and saw no change, doesn't that seem like something is wrong?


If you are REALLY lean at idle, like 20% too lean, an increase of 3-9% still isn't going to get the LOW TRIM to move from 139. I still say you need to raise the base fuel pressure to get the trims right first. Your extreme leanness is just going to aggravate the stalling issue.
 

deez

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To me this sounds like a vacuum leak, although I can't find one. Extreme lean condition at idle/low rpm, when there is the most vacuum, makes sense. And also when coming to a stop the car is pulling a ton of vacuum, which could make the car stall as well. Sound right? I don't see how the car can be 20% lean at idle, and out of nowhere. It doesn't make sense. But who said Mitsubishi's make sense /ubbthreads/images/graemlins/smile.gif
 

Perhaps, but it would have to be a HUGE leak to also get the HIGH TRIM to 139, IMO.
 

deez

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May 29, 2004
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Chico, CA
The weekend I will bump it up to 43 and zero out the safc and see what happens.
 

Armitage

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Herndon, VA
Great thread. I never realized it because I hadn't been paying attention but my car is barely showing over 13v at idle or even at 5000rpm once warmed up. May be why it's been stalling when hot /ubbthreads/images/graemlins/wink.gif I have a spare DSM alternator I could try swapping in but I'm not sure it's worthwhile to put in a 75amp unit.
 

Armitage

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Oct 16, 2003
Messages
715
Location
Herndon, VA
Changed my alternator yesterday afternoon, doesn't seem to make any difference. I see a hair over 14v when the car first starts, idles and revs. Once it warms up it starts to drop below 14 then the car starts to sputter when returning to idle from revving. I'm going to clean up all the battery terminals and see if that makes any difference and if not, get my battery tested.
 

toybreaker

iconoclast
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Apr 30, 2006
Messages
3,581
Do you have heatshields on the exhaust/downpipe?

Original equipment mitsubishi alternators have a very aggressive thermal compensation curve. They will taper their charging voltage significantly if they are getting toasty...
 

deez

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May 29, 2004
Messages
1,150
Location
Chico, CA
Today I tried putting the stock MAS and appropriate chip in the ecu and it made the issue worse. Idle is now searching around when sitting still, stumbling/stalling is the same. Strange that putting the car back to stock in that regard made it worse. Anyone want a car? /ubbthreads/images/graemlins/smile.gif
 

deez

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Joined
May 29, 2004
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1,150
Location
Chico, CA
I forgot, I did bump up the fuel pressure to 43psi, and it helped the trims but not the stalling. Now I think I need to bump it back down because with the stock MAS and the safc zero'ed out, its pig rich at idle, reading 38 on the logger. And from what I recall, with this setup before I added the 3G mas, the safc was pulling a touch of fuel out at idle , but not much. I'm wondering if the pig rich condition is a hint at the real underlying issue.
 

deez

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May 29, 2004
Messages
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Chico, CA
Now that the computer has been run for a few days, the idle is no longer pig rich, but just the opposite at full lean. There has got to be some sensor throwing this thing off, but I have no idea where to go from here. I would like to try a different computer, so if anyone out there had a spare socketed computer I can use, PM me. The local Mitsu dealer says they will check it out, but I have to put it back to stock for that. If thats the case, I will part out the car.
 
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