Jump to content
LegacyGT.com

Curing Low Rev Stumble By Replacing Crank/Cam Sensors?


Recommended Posts

  • Replies 62
  • Created
  • Last Reply
  • 2 weeks later...

How linear is your timing map btw? I saw this post by NSFW couple weeks ago, and decided to try adding more timing down low for mine. It seemed to have made the engine a good bit smoother.

 

Timing testing, please note this map might not be safe, still testing!

http://i160.photobucket.com/albums/t188/covertrussian/Cars/05%20LGT/ECU/Timing%20Advance/05LGTCruiseTimingV1.png~original

 

Compared to stock

http://i160.photobucket.com/albums/t188/covertrussian/Cars/05%20LGT/ECU/Timing%20Advance/05LGTBaseTiming.png~original

05 LGT 16G 14psi 290whp/30mpg (SOLD)

12 OBP Stock 130whp/27mpg@87 Oct

00 G20t GT28r 10psi 250whp/36mpg

22 Ascent STOCK

Link to comment
Share on other sites

  • 1 month later...

Just found out that stock tune likes to run the fuel pump at 33% - 66% duty cycles. Which is not good for aftermarket pumps, this could be causing the stumble as you hit the 33% duty cycle...

http://www.romraider.com/forum/viewtopic.php?f=34&t=6356

 

STi Mikey Confirmed that it fixed his stumble: http://www.romraider.com/forum/viewtopic.php?p=69216#p69216

05 LGT 16G 14psi 290whp/30mpg (SOLD)

12 OBP Stock 130whp/27mpg@87 Oct

00 G20t GT28r 10psi 250whp/36mpg

22 Ascent STOCK

Link to comment
Share on other sites

  • 4 months later...
Bump... Russian have you tried the fuel pump fix?

 

Seems like my stutter is almost always at 2k rpm at low load.

 

I bypassed the in tank fuel filter yeah, definitely no stumbling now (not that I could notice it before though). Here is the guide: How to: Convert Intank Fuel Filter (05+ LGT/OBX 08+ WRX/STI) to Engine Bay Filter

05 LGT 16G 14psi 290whp/30mpg (SOLD)

12 OBP Stock 130whp/27mpg@87 Oct

00 G20t GT28r 10psi 250whp/36mpg

22 Ascent STOCK

Link to comment
Share on other sites

I'm wondering if this could be the cause of my 2K RPM stumble. At least a couple times a month my car would stumble which would lead to the famous "limp" mode. Been like this for the past year. Even after changing spark plugs, checking all vacuum lines and replacing worn fuel lines. Then I figured out that if I put a bottle of fuel injector cleaner in at every other fuel up, the problem doesn't happen.

 

Could this be a fuel pump/filter issue, or the fuel injectors need replacing/serviced?

My wife's balls are delicious.
Link to comment
Share on other sites

I already know that I need to change the O-rings on the injectors, because on cold days (45 or below) I will smell fuel on start up until it's fully warmed up. May just take them out and have them rebuilt at that point, just to make sure the injectors are good. I'll look into the FP filter at that time.
My wife's balls are delicious.
Link to comment
Share on other sites

My fuel pump line's oring was shot after removing it just twice. I probably reinstalled it at an angle and it scratched it off, especially if it was still wet from fuel. Same thing can happen with the fuel rail ones.

05 LGT 16G 14psi 290whp/30mpg (SOLD)

12 OBP Stock 130whp/27mpg@87 Oct

00 G20t GT28r 10psi 250whp/36mpg

22 Ascent STOCK

Link to comment
Share on other sites

  • 2 months later...

@RallyMachine If your still having issues you should try to replace your FPR with 04-07 STI one and change the FPR vacuum source to the BOV line. I just did this on my car and the stumble has been reduced quite a bit.

 

http://i160.photobucket.com/albums/t188/covertrussian/Cars/05%20LGT/Engine/Fueling/FPR/STI-FPR_010.jpg~original

 

More details in the "The famous stumble...fixed?" thread.

05 LGT 16G 14psi 290whp/30mpg (SOLD)

12 OBP Stock 130whp/27mpg@87 Oct

00 G20t GT28r 10psi 250whp/36mpg

22 Ascent STOCK

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.




×
×
  • Create New...

Important Information

Terms of Use