I need some help tuning for bigger injectors
07-24-2018, 06:37 PM
#1
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Thread Starter
I need some help tuning for bigger injectors Before I drive myself completely crazy trying to figure this out I figured I’d ask y’all for some help. When tuning for bigger injectors (36lb/hr) are there any major adjustments that need to be made to the VE table or idle air table? The car has already been tuned for a bigger cam, ls6 intake, and headers so the VE table has been adjusted for that. Everywhere I look there are conflicting answers about what needs to be changed. I have already implemented the data supplied by the injector manufacturer and the car starts and runs fine but it smells pretty rich at idle. Some people say that all you have to do is put that data in, others say that you have to go over all the airflow tables.
07-24-2018, 08:17 PM
#2
Data is data for the injector. That information should be accurate therefore requiring no change. Look into your VE or MAF (or both). However start by logging it. See what the fuel trims and o2 sensors are doing and work from there. Post a log if you'd like and I will take a look.
07-24-2018, 09:27 PM
#3
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Thread Starter
Data is data for the injector. That information should be accurate therefore requiring no change. Look into your VE or MAF (or both). However start by logging it. See what the fuel trims and o2 sensors are doing and work from there. Post a log if you'd like and I will take a look.
07-25-2018, 10:08 AM
#4
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Thread Starter
this is the data after i swapped the injectors. I dont know what the deal is with the O2 sensors reading at low rpm. it drives pretty bad at part throttle but it pulls hard at wot and the AFR looks fairly decent at wide open. If i need to upload the tune i can do that too
07-25-2018, 05:20 PM
#5
this is the data after i swapped the injectors. I dont know what the deal is with the O2 sensors reading at low rpm. it drives pretty bad at part throttle but it pulls hard at wot and the AFR looks fairly decent at wide open. If i need to upload the tune i can do that too
Once it is fixed it will read "CL-NORMAL" for the fuel system status PID just above your fuel trims.
07-25-2018, 05:36 PM
#6
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Thread Starter
The car is not entering closed loop for the fuel trims to read. The o2 voltage is virtually meaningless unless it does this to start utilizing them hence why the short and long term trims stay at zero. Fix that first and relog.
Once it is fixed it will read "CL-NORMAL" for the fuel system status PID just above your fuel trims.
Once it is fixed it will read "CL-NORMAL" for the fuel system status PID just above your fuel trims.
07-25-2018, 05:45 PM
#7
okay. The guy who tuned my car previously disabled both short term and long term fuel trims. Do I just go into the tune and enable these again and write the tune? He also set closed loop enable ECT at 284. I assume I would revert that back to stock too? It looks like he tuned the car to run in open loop all the time maybe?
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07-25-2018, 05:52 PM
#8
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Thread Starter
Its got a decent sized cam(I’m not sure of the specs), 36lb injectors, ls6 intake, headers, SLP lid, straight pipes and a 2800 stall. Are there any benefits to being in open loop all the time? If it would help I can upload the tune so you can see what the previous guy did
07-25-2018, 06:28 PM
#9
Some run it open loop so the fueling is not adjusted. With a hefty cam you can get inconsistencies where o2 sensor doesnt sample correctly and you get erratic fuel changes but it can be alleviated with some work and in most cases a cammed car can stay in closed loop. If its running poorly than you might as well put it in closed loop and see what the car is trying to accomplish via the o2s and how bad it really is....if at all. Some guys are just lazy and tune it fully in open loop.
07-25-2018, 07:00 PM
#10
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Thread Starter
Some run it open loop so the fueling is not adjusted. With a hefty cam you can get inconsistencies where o2 sensor doesnt sample correctly and you get erratic fuel changes but it can be alleviated with some work and in most cases a cammed car can stay in closed loop. If its running poorly than you might as well put it in closed loop and see what the car is trying to accomplish via the o2s and how bad it really is....if at all. Some guys are just lazy and tune it fully in open loop.
07-25-2018, 08:02 PM
#11
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Thread Starter
Some run it open loop so the fueling is not adjusted. With a hefty cam you can get inconsistencies where o2 sensor doesnt sample correctly and you get erratic fuel changes but it can be alleviated with some work and in most cases a cammed car can stay in closed loop. If its running poorly than you might as well put it in closed loop and see what the car is trying to accomplish via the o2s and how bad it really is....if at all. Some guys are just lazy and tune it fully in open loop.
07-26-2018, 12:48 AM
#12
Well the car is pegged dumping 25% fuel on the long terms and the shorts are not much better. This car looks like it needs some help (these are the issues that arise from running closed loop with a cam). A good majority of that is probably crappy sampling. Post your tune please. Don't run the car like this anymore. The o2s will die eventually. Do you have a wideband in the car or no? Probably best for now to disable to the long term trims and work on the short terms first, see if those can be cleaned up enough. Ill know once I see the tune but what headers are on the car and is this car MAF, SD or both?
Got alittle forgetful but I see you mentioned the VE being tuned for the cam so if you just simply swapped injectors than we gotta focus on that first. What injectors and where are you getting the data from?
Got alittle forgetful but I see you mentioned the VE being tuned for the cam so if you just simply swapped injectors than we gotta focus on that first. What injectors and where are you getting the data from?
07-26-2018, 09:10 AM
#13
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Thread Starter
Well the car is pegged dumping 25% fuel on the long terms and the shorts are not much better. This car looks like it needs some help (these are the issues that arise from running closed loop with a cam). A good majority of that is probably crappy sampling. Post your tune please. Don't run the car like this anymore. The o2s will die eventually. Do you have a wideband in the car or no? Probably best for now to disable to the long term trims and work on the short terms first, see if those can be cleaned up enough. Ill know once I see the tune but what headers are on the car and is this car MAF, SD or both?
Got alittle forgetful but I see you mentioned the VE being tuned for the cam so if you just simply swapped injectors than we gotta focus on that first. What injectors and where are you getting the data from?
Got alittle forgetful but I see you mentioned the VE being tuned for the cam so if you just simply swapped injectors than we gotta focus on that first. What injectors and where are you getting the data from?
07-26-2018, 12:46 PM
#14
Here is the tune. I'm pretty sure the car is MAF only. I have a wideband on the way, it should be here today. The headers are 1 7/8" long tubes idk the brand, they came with the car. The injectors are FIC 36lb i got the data from the manufacturer. What will need to be done to the VE table and how can the the fuel trims be cleaned up?
07-26-2018, 07:09 PM
#15
I believe you are on the right path, getting a wideband on the car will help you. 1 thing to know is a lot of pro tuners are lazy. Instead of tuning the VE or MAF tables they rape the injector flow table. Not saying that's what happened just throwing it out there. Post the file they made and someone can surely tell if it was a good tune or not
07-28-2018, 08:58 AM
#16
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Thread Starter
I believe you are on the right path, getting a wideband on the car will help you. 1 thing to know is a lot of pro tuners are lazy. Instead of tuning the VE or MAF tables they rape the injector flow table. Not saying that's what happened just throwing it out there. Post the file they made and someone can surely tell if it was a good tune or not