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Discussion Starter #1 (Edited)
I hate these damn things..was driving fine today, then about 100 yards from my house just boosting, my accordian hose post maf popped off. engine died. was like " ok " popped the hood secured it back on, now my afrs are total whack.

I move the maf ( just placement not actual maf orientation ) and when I mean movement i'm talking Centimeters of where the coupler is going on the pipe.. actually make it mm not cm and afrs go to 20:1, move it little further, 10:1. disconnect my intercooler pipe, back to normal, hook it back up, less then 10:1.. i hate these damn mafs seriously.


also I really don't get how the maf can't correctly read airflow unless it is close to the throttlebody, on a completely closed system, how is airflow different at 5 inches from the TB, to 5 feet? wtf.?
 

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Leaks?
Crap on the MAF Sensor?
Proper MAF Calibration performed?
Do you have a flow straightener before the MAF sensor?

I do know my MAF needs calibration after large temperature changes.

The ACTUAL volume is different at different points in the air system but this is another issue.

Did you change out your MAP sensor? Is the MAP sensor reading the same as an independent Boost Gauge?

Just thinking about possible issues

Z
 

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Discussion Starter #4
well I know I have got to have a vac leak somewhere.. Can't find it though. When I start the car I only get 10-12 vac for the first minute, then the car will hesitate, then vac will jump to 18-20 and usually stay there for the rest of the day. This only happens on a fully cold start. I would like to know the location of the map sensor on the 2.5 engines.

as for flow straightening I'm using the stock maf housing cut out of the intake box, what I'm thinking it could be is that my intercooler pipe is 2.5 inches, going to a 2.5 to 3 inch coupler, connected to the 2.75? Maf housing, which could be causing pressure / air turbulence differentials.
 

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well I know I have got to have a vac leak somewhere.. Can't find it though. When I start the car I only get 10-12 vac for the first minute, then the car will hesitate, then vac will jump to 18-20 and usually stay there for the rest of the day. This only happens on a fully cold start. I would like to know the location of the map sensor on the 2.5 engines.

as for flow straightening I'm using the stock maf housing cut out of the intake box, what I'm thinking it could be is that my intercooler pipe is 2.5 inches, going to a 2.5 to 3 inch coupler, connected to the 2.75? Maf housing, which could be causing pressure / air turbulence differentials.
you answered your own question in the last sentence
 

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Can i suggest that the turbo and plumbings be tuned for idle first?

Its suffocating, then when engine demands more air trying to see where everything is at, turbo spools, then things go out of spec.

30 mins after the ecu has been reset, whats the idle maf reading? My current reading are 0.27 lb/min(assuming this is stock, avg value). Should be less than .3

Can be your engine is working too hard to get that value.



Something to do with the feedback loop as well, can it be changing too fast?
 

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Low turbulence and low velocity are the key to accurate maf readings. That's why it's placed close to the intake filter and air staighteners are used.
 

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Discussion Starter #8 (Edited)
I'm getting about 2 to 3.xxlb/min at idle from my maf not 0.3 but 3.xx or high 2's. Well I have no idea where I could put the maf on this where turbolence/velocity would be low..if I put the maf pre turbo it idles like shit and afrs are 20s or it starts and dies.

also the turbo is always spooling, turbo spools whike the car is cranking, don't think the issue is engine choking
 

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I'm getting about 2 to 3.xxlb/min at idle from my maf not 0.3 but 3.xx or high 2's. Well I have no idea where I could put the maf on this where turbolence/velocity would be low..if I put the maf pre turbo it idles like shit and afrs are 20s or it starts and dies.

also the turbo is always spooling, turbo spools whike the car is cranking, don't think the issue is engine choking
Sure your not lookin at gram rates?


Sent from my Autoguide iPhone app
 

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Discussion Starter #10
Sorry just checked again was gram rates sorry. My idle lb min is 0.3lb. Also i think i found my "lean" issue. The gas vapor purge solenoid was malfunctioning. I took the vac line off closed it up, and idle went right too 14.7 bouncing to 15.3 once in a while, then back to 14.7. Goes into 16.00s while driving but probably because i have 4 gallons of ethanol in the tank. Also moved my maf so its a perfect straight shot from the throttle about 3 inches away.


Either the solenoid was back or i hooked it up backwards when i took it off a while ago, either way idle seem good now *crosses fingers *
 

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Nice find. Hope that solves it, progress is good.

...

Mmm, have the evap plug in the right way and reset ecu, monitor it the next few days. Capping the line will have the engine do something silly, as evap is the last sensor ecu watches(on mine anyways) during learning mode.
 

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VIDEOS!!!!11!!one!!! lol
 

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the car if its fixed. I only saw one of the car driving on youtube
 
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