Idle issues with EFI Live and LTX?
05-10-2012, 03:42 PM
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Idle issues with EFI Live and LTX? Anyone care to take a look at my tune. Here is my setup. Any help would be appreciated.
Forged 9.2:1 compression 383
TC-78 pushing 10psi
80lb injectors
CNC'd Brodix 230cc heads and matched Holley single plane
Dual Walbro 255lph pumps, one on at 6psi-stock fuel lines-holley rails and AFPR
24X EFI Connection conversion
Cam-224/224 .577/.582 114 LSA
Springs-Comp 26094-16. Seat load: 178lbs @1.900''_Open load: 459lbs @1.275_Rate: 449lbs/in
LS7 Lifters
Pulls great, but start up is rough and doesn't idle very well. I have to elevate the idle for the first couple minutes then it idles OK, but just getting it started sometimes takes 5 or more tries. Part throttle is alright, but It could be better. When its hot and been sitting with engine off for 10-20 minutes, upon restart it idles real low and the revs don't come up when depressing throttle. Dyno tuner doesn't think EFI Live is capable of tuning the idle, something about transient fueling, so he switched to HP tuners, I want to use EFI Live so I can make adjustments myself.
Dyno sheet. Think it hit the rev limiter at 5900ish rpm.
Forged 9.2:1 compression 383
TC-78 pushing 10psi
80lb injectors
CNC'd Brodix 230cc heads and matched Holley single plane
Dual Walbro 255lph pumps, one on at 6psi-stock fuel lines-holley rails and AFPR
24X EFI Connection conversion
Cam-224/224 .577/.582 114 LSA
Springs-Comp 26094-16. Seat load: 178lbs @1.900''_Open load: 459lbs @1.275_Rate: 449lbs/in
LS7 Lifters
Pulls great, but start up is rough and doesn't idle very well. I have to elevate the idle for the first couple minutes then it idles OK, but just getting it started sometimes takes 5 or more tries. Part throttle is alright, but It could be better. When its hot and been sitting with engine off for 10-20 minutes, upon restart it idles real low and the revs don't come up when depressing throttle. Dyno tuner doesn't think EFI Live is capable of tuning the idle, something about transient fueling, so he switched to HP tuners, I want to use EFI Live so I can make adjustments myself.
Dyno sheet. Think it hit the rev limiter at 5900ish rpm.
Last edited by LT1 POWR; 05-10-2012 at 04:26 PM.
05-10-2012, 11:47 PM
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What does your AFR look like at idle? Have you done the CAX file mod to your tune so you can edit B9021 "Transient Minimum Pulsewidth"?
This might be what your tuner was referring to. If you don't change this, the injectors will stay open way too long at idle - especially with 80lb injectors. Factory setting is something like 1.28ms. You'll probably need to drop it down to something in the neighborhood of 0.7 to 0.8 ms. Best bet is to find the data for your injectors and understand what minimums they're capable of operating at and set it based on that.
From there, you'll need to dial in your B4307 "Desired Airflow" table. Keep an eye on IAC counts at this stage. At a warm idle, you want them to be in the range of 60-80 "steps". Any less and the idle might get a little high on you occasionally. Higher number of steps would indicate the engine is starving for idle airflow and the IAC valve is accounting for it.
This might be what your tuner was referring to. If you don't change this, the injectors will stay open way too long at idle - especially with 80lb injectors. Factory setting is something like 1.28ms. You'll probably need to drop it down to something in the neighborhood of 0.7 to 0.8 ms. Best bet is to find the data for your injectors and understand what minimums they're capable of operating at and set it based on that.
From there, you'll need to dial in your B4307 "Desired Airflow" table. Keep an eye on IAC counts at this stage. At a warm idle, you want them to be in the range of 60-80 "steps". Any less and the idle might get a little high on you occasionally. Higher number of steps would indicate the engine is starving for idle airflow and the IAC valve is accounting for it.
05-10-2012, 11:54 PM
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My tuner isn't familiar with EFI Live and is now refusing to use it. What is this mod and how is it performed. I don't have a wideband hooked up yet.
What does your AFR look like at idle? Have you done the CAX file mod to your tune so you can edit B9021 "Transient Minimum Pulsewidth"?
This might be what your tuner was referring to. If you don't change this, the injectors will stay open way too long at idle - especially with 80lb injectors. Factory setting is something like 1.28ms. You'll probably need to drop it down to something in the neighborhood of 0.7 to 0.8 ms. Best bet is to find the data for your injectors and understand what minimums they're capable of operating at and set it based on that.
From there, you'll need to dial in your B4307 "Desired Airflow" table. Keep an eye on IAC counts at this stage. At a warm idle, you want them to be in the range of 60-80 "steps". Any less and the idle might get a little high on you. Higher number of steps would indicate the engine is starving for idle airflow and the IAC valve is accounting for it.
This might be what your tuner was referring to. If you don't change this, the injectors will stay open way too long at idle - especially with 80lb injectors. Factory setting is something like 1.28ms. You'll probably need to drop it down to something in the neighborhood of 0.7 to 0.8 ms. Best bet is to find the data for your injectors and understand what minimums they're capable of operating at and set it based on that.
From there, you'll need to dial in your B4307 "Desired Airflow" table. Keep an eye on IAC counts at this stage. At a warm idle, you want them to be in the range of 60-80 "steps". Any less and the idle might get a little high on you. Higher number of steps would indicate the engine is starving for idle airflow and the IAC valve is accounting for it.
05-11-2012, 12:19 AM
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Info can be found in the CAX forum on EFI's site. Check the stickies, make a post if you don't see what you need for your operating system, and they'll help you out. Made a huge difference on my D1SC car that was running 60lb injectors. You're going to want to get that WBO2 hooked up soon so you can see what's going on (like before you make any changes to the tune).
http://forum.efilive.com/forumdisplay.php?74-CAX-Files
Forum ^^
http://forum.efilive.com/forumdisplay.php?74-CAX-Files
Forum ^^
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05-11-2012, 01:33 AM
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Whats it supposed to be? I didn't adjust anything in this file since it left the tuner. Would this cause the issues I've been experiencing? I don't know much about tuning, been trying to read up on it, but there is so much.
05-11-2012, 03:53 AM
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1:Not sure.
2:Setting with correct data will certainly help your issue.
Your Injector Flow Rate looks correct if you are using 58psi. The rest of the injector info in the tune looks sketchy to me. Having the correct injector data for your injectors is one the most over looked things I see. Racetronix sells that injector. Try emailing there customer service and asking nicely for any programing data they have. Maybe they will have it.
I did find this link which is Furd style injector data for these injectors in quick search.
http://siemensdeka.com/specsheets/FI114992cs.jpg
05-12-2012, 10:17 AM
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A couple of quick observations after looking at the tune and reading your comments.
- EFILive does have access to the transient tables. They're listed under Engine Calibration > Fuel > Dynamics. But these are not the cause of your idle problems.
- What is the ECT when this happens? Do you have a log?
- This is usually because it's too lean on start up. Your OL Commanded AFR is commanding 14.63 at most temps and kPa and your afterstart enrichment is low (.02) in the hotter temps. Try increasing the enrichment value to .04 and see if that helps. This is a EQ Ratio value.
- Even though you have a small cam with low overlap; I would increase the idle rpms and desired airflow to dial in the idle rpm. Once stabilized you can work on lowering the idle rpms.
-Another thing to look at is the spark tables. The values in high/low octane table should match or be very close to the base spark in gear and P/N tables. Your tables are all over the place. Spark goes a long to help stabilize idle.
- The Scan Tool is your best friend when tuning. Use the DVT bi-directional controls to work on the spark, AFR, idle rpms and IAC to help pin point the problem areas.
- EFILive does have access to the transient tables. They're listed under Engine Calibration > Fuel > Dynamics. But these are not the cause of your idle problems.
When its hot and been sitting with engine off for 10-20 minutes, upon restart it idles real low and the revs don't come up when depressing throttle
- This is usually because it's too lean on start up. Your OL Commanded AFR is commanding 14.63 at most temps and kPa and your afterstart enrichment is low (.02) in the hotter temps. Try increasing the enrichment value to .04 and see if that helps. This is a EQ Ratio value.
- Even though you have a small cam with low overlap; I would increase the idle rpms and desired airflow to dial in the idle rpm. Once stabilized you can work on lowering the idle rpms.
-Another thing to look at is the spark tables. The values in high/low octane table should match or be very close to the base spark in gear and P/N tables. Your tables are all over the place. Spark goes a long to help stabilize idle.
- The Scan Tool is your best friend when tuning. Use the DVT bi-directional controls to work on the spark, AFR, idle rpms and IAC to help pin point the problem areas.
08-11-2021, 07:07 PM
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I purchased a 1972 el camino with a 2002 5.3L from a chevy Silverado. It has a 1998 camaro cam and intake manifold with 2002 LS6 camaro injectors.
It idles fine if the car is not moving. It stalls sometimes when coming to a stop. I think it has just the factory tune.
Which software are you using or would recommend?
Thanks
It idles fine if the car is not moving. It stalls sometimes when coming to a stop. I think it has just the factory tune.
Which software are you using or would recommend?
Thanks
