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Car runs rough with MAF plugged in (a known good MAF)

CAFIFTY

Active member
Joined
Feb 17, 2013
Messages
27
Location
Kzoo, Michigan
Yeah i used VFAQ and did the whole process for the BISS and idle switch. Car will idle at 750 but it moves around a bit and sounds like its going to die. I wish i had a logger. I am going to try to make one, it would make this 100 times easier.
 

James

Well-known member
Joined
Apr 7, 2012
Messages
1,322
Location
Port richey Florida
If I wasn't getting ready to go on a 3,000 mile road too is send you my logging setup till you get your problem worked out!

I do suggest picking up a setup though. Best money spent.
 

CAFIFTY

Active member
Joined
Feb 17, 2013
Messages
27
Location
Kzoo, Michigan
Changed knock sensor. Still the same. Changed CAS and set timing to +5 per the vfaq procedure: nothing changed. Change the coil pack (which is stupid hard to get out: nothing changed. :
Pinned out MAF:
Pin 1: 11.7v
Pin 2: 5v
Pin 3: 11.7v
Pin 4: 5v
Pin 5: nothing there
Pin 6: 50 ohms?
Pin 7: 0v
Pin 8: 0v

Not sure what to expect out of 7 and 8. 50 ohms seemed high for 6...


I should state that after i did the boost check and sealed some things up the car was able to idle with the MAF in and drive in WOT conditions with the MAF in. But surges like crazy in part throttle/vacuum. Maybe i have a leak upstream of my TB.

 
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CAFIFTY

Active member
Joined
Feb 17, 2013
Messages
27
Location
Kzoo, Michigan
Built the logger cable and it wont connect using the TMO logger via my laptop/com port. Out of frustration I pour a thing of seafoam injector cleaner in the car. Drives even worse now. Can barely make it out of the driveway. Ugh i hate this car.
 

FlyingEagle

Staff member
Joined
Mar 5, 2005
Messages
1,635
Location
THE Ottawa
Quoting CAFIFTY:
Built the logger cable and it wont connect using the TMO logger via my laptop/com port. Out of frustration I pour a thing of seafoam injector cleaner in the car. Drives even worse now. Can barely make it out of the driveway. Ugh i hate this car.



Did you change your spark plugs after this ??
You'll have to get a logger up and running before moving any further.
 

CAFIFTY

Active member
Joined
Feb 17, 2013
Messages
27
Location
Kzoo, Michigan
Yeah, this is really hard without a logger. If I could see fuel trims/tps/MAF signals it would make life so much easier.

After posting this i pulled my TPS off and check the ohms closed and opened.

Closed
Pin 1 to 4: 4.7k ohms
Pin 2 to 4: 0.9k ohms

Open
Pin 2 to 4: 4.8k ohms

The open reading is a little low but nothing ridiculous.


Back to the logger.
Has anyone used the TMO logger software on a laptop and built their own cable? I am not using a null modem because I have a DB9 COM port on my laptop. I built my wire based off this schematic which was for the MMcd logger. I figured its the same though..
 

CAFIFTY

Active member
Joined
Feb 17, 2013
Messages
27
Location
Kzoo, Michigan
Maybe this problem was a gift. I just stumbled across tunerpro , there is no way this can be as good as it clams. If so i am selling my AEM that is collecting dust.
 
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thecman02

Well-known member
Joined
Nov 3, 2007
Messages
917
Location
Kalamazoo,MI
Hey sorry I haven't saw this post or I'd help you out. Are you actually in Kalamazoo? I have a known good logging cable. I was using it with my old palm but the serial to palm cable got worn out and the battery in the palm keeps a charge for about 30 minutes max. I ended up getting ECMlink about the time that all started happening too because burning chips became a nuisance.
 
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CAFIFTY

Active member
Joined
Feb 17, 2013
Messages
27
Location
Kzoo, Michigan
Finally got time to work on this again. Turns out I am dyslectic and pined my cord backwords. TMO and TunerPro RT work with the cord.

Here are the things that stuck out:

At idle (and everywhere) the 02 sensor read 0.02v (lean as hell) but i think it might not be functioning correctly (should be switching).

ECT was reading correctly in TMO but was reading 120 degrees higher when viewing it TunerPro RT. I think i read somewhere that the ECT sensor is different in the VR4 then in other DSMs so i have concerns that the talon ECU i swapped in is confused?

Idle switch never goes high.

FTL FTM and FTH are all reading near 1. I am assuming these are fuel trims and i would assume if the 02 sensor was really reading 0.02V all the time the fuel trims would start adding fuel. But it might be stuck in open loop

So i am starting to think that my fuel pump is bad in addition to my 02 sensor. Tell me what you think
 
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460GVR4

Well-known member
Joined
Jan 30, 2012
Messages
87
Location
tacoma, wa
I've replaced/checked/tested every electrical component on my vr4 and still have issues.. Don't feel so bad bro. My car is cursed garunteed.
 

CAFIFTY

Active member
Joined
Feb 17, 2013
Messages
27
Location
Kzoo, Michigan
Had some time to mess with the car again today. Fuel pressure turned out good (maybe a little high). I unplugged the o2 sensor and the seemed to run better. This made me think one of the fuel injectors might be messed up. I pulled plugs one at a time and found one that didnt seem to make a difference when unplugged. Pulled the fuel injector and found that one was clogged...
 

mitsuturbo

Well-known member
Joined
Jun 2, 2008
Messages
3,551
Location
Near Seattle, Washington
Well, if the ECU came out of a DSM..

It didn't come out of an auto DSM, did it? I mean, they only run 390cc injectors with that little TD04, instead of 450's. Dunno if that could be an issue, but it's worth investigating.

Also, how's the timing? Nothing is off a tooth? T-Belt is all lined up right? CAS is tight and set properly? No adj. cam gears that have slipped?
 

91Vr4white

Active member
Joined
Mar 30, 2013
Messages
26
Location
Owensboro, KY
It has to be mass air related. As stated before it could be a connection issue. Check the pins make sure they are not loose. My guess would be its not the correct mass air for the injectors.
 

CAFIFTY

Active member
Joined
Feb 17, 2013
Messages
27
Location
Kzoo, Michigan
So today i dropped my fuel tank to find its full of rust. My injectors and fuel filter were clogged again (i put about 50 miles on it since i changed them. Going to take it to a local fuel tank repair place and replace the lines
 

tektic

Well-known member
Joined
Dec 19, 2012
Messages
1,497
Location
ronkonkoma, ny
Whats the part number of the ecu your using?
Is your ISC Functioning properly?
Besides your ect everything else is normal?
Did your o2 sensor start working after fixing fuel deliver system?
 
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