60lb injector idle quality
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
60lb injector idle quality I have a totally stock LQ4 and a s475. With a Holley HP system, best idle I can get with the Siemens injector is 650 rpm, about 19" of vac. The injec PW is 1.5 ms. I stuck the stock inj back in, and I can get the idle down to 500-550, which is probably stock. Their PW was around 2.5 ms.
Sort of a newby here with LS motors, and I havent done a bunch of tuning yet, but I changed the idle AFR to 14.0 from 14.7 and it idled slightly better. Taking the idle timing to 30* from a base of 22* also helped.
I saw some tech specs on the Siemens injectors, and I think I read that the min PW is about 1.5, which is were mine were operating at.
Is this about it as far as idle quality?
Sort of a newby here with LS motors, and I havent done a bunch of tuning yet, but I changed the idle AFR to 14.0 from 14.7 and it idled slightly better. Taking the idle timing to 30* from a base of 22* also helped.
I saw some tech specs on the Siemens injectors, and I think I read that the min PW is about 1.5, which is were mine were operating at.
Is this about it as far as idle quality?
i cant get my idle afr any higher then 11 at idle with mine on a 5.3. think i need an adjustable regulator. even if i command 18:1 it wont change... lol think the pulsewidths are around 1.5. wont go lower no matter what i try for the injector min pulse width and whatever. gonna try to mess with the offsets some more. dont know why offsets for these injectors so such a highly guarded secret unless you buy a 250 dollar banish dvd.
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
Possible.
I assumed the idle speed should be around 550, as my 01 Tahoe idles there with the same cam I believe. And again, I could get it to idle at 550 with the 28lb'ers.
I tried fattening it up, leaning it out, more/less timing. Best idle I could get was 650 with an AFR of about 13.7, and 30* of timing. Gives me a kpa of 31 = around 19-20" of vacuum.
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
Do you feel the 60's should be able to idle just as well as the OE 28 lbs'ers?
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9 Second Club
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From: Norn Iron
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After some research, I found that there is a table that sets a minimum transient pulsewidth (B9021- hidden until I added the .cax file) that will override the minimum pulsewidth defined in B4003. I am using EFI Live on a 0202003 OS. If you're using HP Tuners, I'm not sure what the equivalent table would be. My default value in this table was 1.27xxxx, and the new value has to be lower than that set in B4003 to force the computer to use B4003 instead of B9021. I set mine at .75. I plan on loading the new calibration tomorrow and taking the car for a drive. I'll report back with the results. I'm hoping this helps with lean tip-in and rich decel.
You may also need to visit the B4005 Small Pulse Adjust and B3701 Injector Pulse Width Voltage Adjustment as they will have an big impact at idle as well. I had mine set at 0.4103 ms @ 14V which is around stock.
i run 80lb injectors @ 58psi fuel pressure on a stock cam/heads/intake turbo 4.8l
siemens decka USCAR 80lb injectors from lethal performance,
with a MS1 Ecu and i can make it start and idle beautifully.
the injectors are linear and have no problem flowing super low pulse widths, i am using about 1.2 % duty cycle at idle.
siemens decka USCAR 80lb injectors from lethal performance,
with a MS1 Ecu and i can make it start and idle beautifully.
the injectors are linear and have no problem flowing super low pulse widths, i am using about 1.2 % duty cycle at idle.
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
This is the default specs in the Holley software. Does this look pretty good to you guys?
Again, motor idles good at 650, I just cant idle it at 550 like the stock injectors did.
Siemens Deka IV High Impedance "60 lb/hr"
Offtime curve at 60 psi
8.0 V 1.64
8.8 V 1.38
9.6 V 1.18
10.4 V 1.03
11.2 V .91
12.0 V .81
12.8 V .74
13.6 V .68
14.4 V .62
15.2 V .55
16.0 V .49
16.8 V .45
17.6 V .42
18.4 V .37
19.2 V .33
20.0 V .29
Again, motor idles good at 650, I just cant idle it at 550 like the stock injectors did.
Siemens Deka IV High Impedance "60 lb/hr"
Offtime curve at 60 psi
8.0 V 1.64
8.8 V 1.38
9.6 V 1.18
10.4 V 1.03
11.2 V .91
12.0 V .81
12.8 V .74
13.6 V .68
14.4 V .62
15.2 V .55
16.0 V .49
16.8 V .45
17.6 V .42
18.4 V .37
19.2 V .33
20.0 V .29
9 Second Club
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From: Norn Iron
Never used Holley before, so cant comment there.
On my own ecu I calculated injector dead time at around 0.65ms at 14v so the numbers above seem ok in that respect. Cannot comment at other voltages as I dont have that info.
As to how the Holley is wired or configured I have no idea though and could affect how the system performs.
I'll at least assume the injectors are wired and fired sequentially ? And they are firing in the correct order and not at some ridiculous time ?
On my own ecu I calculated injector dead time at around 0.65ms at 14v so the numbers above seem ok in that respect. Cannot comment at other voltages as I dont have that info.
As to how the Holley is wired or configured I have no idea though and could affect how the system performs.
I'll at least assume the injectors are wired and fired sequentially ? And they are firing in the correct order and not at some ridiculous time ?
Thread Starter
Joined: Nov 2009
Posts: 1,621
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From: THORNTON, PA (NEAR PHILLY)
Never used Holley before, so cant comment there.
On my own ecu I calculated injector dead time at around 0.65ms at 14v so the numbers above seem ok in that respect. Cannot comment at other voltages as I dont have that info.
As to how the Holley is wired or configured I have no idea though and could affect how the system performs.
I'll at least assume the injectors are wired and fired sequentially ? And they are firing in the correct order and not at some ridiculous time ?
On my own ecu I calculated injector dead time at around 0.65ms at 14v so the numbers above seem ok in that respect. Cannot comment at other voltages as I dont have that info.
As to how the Holley is wired or configured I have no idea though and could affect how the system performs.
I'll at least assume the injectors are wired and fired sequentially ? And they are firing in the correct order and not at some ridiculous time ?
Sorry for taking so long for the update. I've driven around for the last 2 days with the B9021 table set at .75 and my minimum pulsewidth is dropping to 1.2 at times. I'm using Siemens Deka 60# with Banish's data. Street driving has improved 100%. I no longer have rich decel or lean tip in. It appears that my car is abiding by the b3647 table much better, but I have some more fine tuning to do. I can finally creep through a parking lot in 2nd gear off the gas without bucking. Also, my car has the hot cam, known for its awful... everything. This is the most driveable my car has been since I bought it. I also adjusted my impact factor table by +30%. I did pull some timing in the "in gear" cells that pertain to idle/off throttle creeping at 800-1200 rpm range (its a m6 car). As I continue to play around with the tune, I'll continue to report my findings.
Thread Starter
Joined: Nov 2009
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From: THORNTON, PA (NEAR PHILLY)
I guess I'm sorta on my own with the Holley ECU huh? Although, I have the ability to adjust all that stuff. Can you guys post whatever details/specs regarding these injectors? There really isnt any tuners around here that I would feel comfortable with.
9 Second Club
Joined: Nov 2003
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From: Norn Iron
Certainly any aftermarket ecu Ive ever tuned this should be very easy. Although Ive never used Holley or seen their software.
