Haltech Modded T2: Problems with injector staging
Thread Starter
Rotary Freak
Joined: Oct 2001
Posts: 1,515
Likes: 1
From: Atlanta, GA
Modded T2: Problems with injector staging
I cant quite figure out what the heck is wrong with my injector staging on my modded S5t2
Power Mods:
Street port S5 Turbo motor
T04B
3inch RB Exh
Tial 38mm wg
Greddy FMIC
Electronics and Fuel:
Haltech e6k
550cc / 1680cc pri/sec injectors
PLX M300 Wideband O2
Walbro 255 lp/hp
Pump fuel premixed
Recent redo of fuel lines up front (In attempt to solve this problem)
Auromotive <?> adjustable FPR NOW running parallel rail delivery set at about 45psi static
OK so on the haltech I have the staging bar set one bar to the RIGHT of zero. I can tell everytime the secondaries come on at about 2psi by my wideband's indication and fluctuation, and also by the engine hesitating and surging.
On acceleration;
When the secondary injectors come on for the first time after sitting for awhile, my WB AF jumps up to 16:1 and sometimes even 17:1 for a split second. Before the Haltech even has time to change to a different BAR, the a/f will settle and drop back down to 'normal' This gets better after a few slow pulls, where it will get to the point of being somewhat stable but still not acceptable. Its almost like there is air in the fuel lines/injectors and the first few pulls are purging the system. After about 2-3 light pulls the problem with accelerating somewhat goes away, but I can still sometimes tell the engine hesitates/misfires a bit; its just not as smooth as I would like it to be.
On decelleration;
The second problem Im having and somewhat related is under deceleration, slowly dropping from say 5psi back down to zero psi. By the time it hits zero, the A/F guage is soo far off the scale that my engine just cant fire!! The a/f drops richer than 10:1 for about 1/4 to 1/2 a second, and in general the entire AF is surprisingly a bunch richer than when accellerating at all times. THIS PROBLEM NEVER GOES AWAY like the acceleration problem.
Attached I've posted what I observe when the problems happen, a datalog will basically show the same thing in comparison which I can provide if absolutly necessary.
Please hlp!
Note download and rename this attachment with a .XLS file extension to open in Excel.
Power Mods:
Street port S5 Turbo motor
T04B
3inch RB Exh
Tial 38mm wg
Greddy FMIC
Electronics and Fuel:
Haltech e6k
550cc / 1680cc pri/sec injectors
PLX M300 Wideband O2
Walbro 255 lp/hp
Pump fuel premixed
Recent redo of fuel lines up front (In attempt to solve this problem)
Auromotive <?> adjustable FPR NOW running parallel rail delivery set at about 45psi static
OK so on the haltech I have the staging bar set one bar to the RIGHT of zero. I can tell everytime the secondaries come on at about 2psi by my wideband's indication and fluctuation, and also by the engine hesitating and surging.
On acceleration;
When the secondary injectors come on for the first time after sitting for awhile, my WB AF jumps up to 16:1 and sometimes even 17:1 for a split second. Before the Haltech even has time to change to a different BAR, the a/f will settle and drop back down to 'normal' This gets better after a few slow pulls, where it will get to the point of being somewhat stable but still not acceptable. Its almost like there is air in the fuel lines/injectors and the first few pulls are purging the system. After about 2-3 light pulls the problem with accelerating somewhat goes away, but I can still sometimes tell the engine hesitates/misfires a bit; its just not as smooth as I would like it to be.
On decelleration;
The second problem Im having and somewhat related is under deceleration, slowly dropping from say 5psi back down to zero psi. By the time it hits zero, the A/F guage is soo far off the scale that my engine just cant fire!! The a/f drops richer than 10:1 for about 1/4 to 1/2 a second, and in general the entire AF is surprisingly a bunch richer than when accellerating at all times. THIS PROBLEM NEVER GOES AWAY like the acceleration problem.
Attached I've posted what I observe when the problems happen, a datalog will basically show the same thing in comparison which I can provide if absolutly necessary.
Please hlp!
Note download and rename this attachment with a .XLS file extension to open in Excel.
Last edited by SaabGuy; Nov 16, 2007 at 07:57 AM.
Thread Starter
Rotary Freak
Joined: Oct 2001
Posts: 1,515
Likes: 1
From: Atlanta, GA
OK I got home and just started tinkering with things... I wanted to check fuel pressure so I pulled the vac line running to to RRFPR. The dial guage jumped up to 49psi while idling! I THOUGHT it was set to 45psi static but I guess I'm a dumbass??
49psi static rail pressure
15psi of turbo boost
-------
=64psi of rail pressure :O
Thats a bit high for a walbro pushing 350rwhp in my opinion
So I lowered the fuel pressure down to 44psi static and poped the vac line back on the reg. A/F went lean by about .5af below boost and below 4500 rpm, so I trimmed areas down a bit and ran a few low boost runs to make sure a/f was still good.
Interesting; engine seems to be running much better all around. I still have the above mentioned issues but I think its honestly about 50% better.
Should I run down to say 42psi static rail? I'm hitting 75% WOT duty cycle running 10.8 to 11 to 1 A/F on the street.
49psi static rail pressure
15psi of turbo boost
-------
=64psi of rail pressure :O
Thats a bit high for a walbro pushing 350rwhp in my opinion
So I lowered the fuel pressure down to 44psi static and poped the vac line back on the reg. A/F went lean by about .5af below boost and below 4500 rpm, so I trimmed areas down a bit and ran a few low boost runs to make sure a/f was still good.
Interesting; engine seems to be running much better all around. I still have the above mentioned issues but I think its honestly about 50% better.
Should I run down to say 42psi static rail? I'm hitting 75% WOT duty cycle running 10.8 to 11 to 1 A/F on the street.
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