Cant get car to idle any leaner than 12:1 with big injectors
04-29-2007, 04:33 PM
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Cant get car to idle any leaner than 12:1 with big injectors I cant seem to get my #83 injectors to idle any leaner than 12:1. I'm using HPT and have tried changing the short pulse adder and the offset vs. volts vs. KPA and they only seem to have changed the part throttle acceleration.
The car wont cruise or idle near 14:1 like I want it to. I'm kinda new to HPT so any help would be welcomed.
The car wont cruise or idle near 14:1 like I want it to. I'm kinda new to HPT so any help would be welcomed.
04-29-2007, 04:51 PM
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Do you need them that large?
Plenty of guys have the same problem. Im not sure there is a solution. You might be at min pulse so cant go any lower.
You can try cheating your IFR table near idle map see if that helps.
Plenty of guys have the same problem. Im not sure there is a solution. You might be at min pulse so cant go any lower.
You can try cheating your IFR table near idle map see if that helps.
04-30-2007, 10:46 PM
#5
Is fuel pressure set to 45-50lbs at idle? Just use the boost reference on the regulator -no vacuum reference.You should only have to change the IFR table to around a 83lb range.Then tune it in the ve table. -I'm guessing you are 2-3 bar SD.
I've had no problem tuning 96's this way.Truck idles at 14.5-1 A/F.
I've had no problem tuning 96's this way.Truck idles at 14.5-1 A/F.
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05-02-2007, 01:05 PM
#9
Originally Posted by ABeasst
I already have a boost regulator but I'll try and pull out even more fuel from the VE table. Yes I am 3bar SD.
The only big difference I see is that I'm running 2 bar with a Versafueller.
05-02-2007, 01:53 PM
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yea I have it set to 45#. I tried pulling 30% out of the main VE table and it still idled the same. The only affect it seemed to have was when I tried to drive the car would max the wideband and try to knock off.
05-02-2007, 02:11 PM
#11
i don't think that idle is in the ve. i'm not saying that as fact. when i changed injectors from 26 to 37's, i changed the ifr and idle was stock feel and afr. this is on a stock na car.
then i had to do other adjustments in ve and maf for drivability.
then i had to do other adjustments in ve and maf for drivability.
05-02-2007, 05:21 PM
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You tell by manufacturer specifications. They can tell you the minimum pulse width performance of their injector, how it performs at a given voltage, and then you adjust the tune to reflect those performance specs. If it still doesn't work after that, then you need to guess and apply the 'fudge factor.'
05-03-2007, 10:07 PM
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Originally Posted by Slowhawk
Try putting the VE back and then add 5% to the IFR table(whole thing)
05-03-2007, 11:58 PM
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Probably a stupid question but i got to ask these are low impedance injectors and you are running an injector driver right? What is the pulse width at idel? and what is the min pulse width set at?
05-08-2007, 12:05 PM
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UPDATE: I figured I would give an update to help anyone in the future trying to get big injectors to idle and cruise with HPT. I have got the car idling and cruising around 13.5-14:1. I ended up changing:
*the short pulse limit to 1.44 so it would not add any fuel except at idle.
*rescaled the short pulse adder
*I lowered the min. injector pulse and default injector pulse.
*rescaled my entire EQ ratio table for open loop (no longer 1 like it was originally)
thanks to everyone that helped, especially Slowhawk.
*the short pulse limit to 1.44 so it would not add any fuel except at idle.
*rescaled the short pulse adder
*I lowered the min. injector pulse and default injector pulse.
*rescaled my entire EQ ratio table for open loop (no longer 1 like it was originally)
thanks to everyone that helped, especially Slowhawk.
05-08-2007, 12:10 PM
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Originally Posted by ABeasst
UPDATE: I figured I would give an update to help anyone in the future trying to get big injectors to idle and cruise with HPT. I have got the car idling and cruising around 13.5-14:1. I ended up changing:
*the short pulse limit to 1.44 so it would not add any fuel except at idle. Why did you pick 1.44?
*rescaled the short pulse adder Rescaled how and why?
*I lowered the min. injector pulse and default injector pulse. Lowered to what? Why?
*rescaled my entire EQ ratio table for open loop (no longer 1 like it was originally)
thanks to everyone that helped, especially Slowhawk.
*the short pulse limit to 1.44 so it would not add any fuel except at idle. Why did you pick 1.44?
*rescaled the short pulse adder Rescaled how and why?
*I lowered the min. injector pulse and default injector pulse. Lowered to what? Why?
*rescaled my entire EQ ratio table for open loop (no longer 1 like it was originally)
thanks to everyone that helped, especially Slowhawk.
05-08-2007, 12:40 PM
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I used 1.44 because the only time it was that low or lower was at idle, therefore the PCM does not go to the short adder table when leaving off idle or going down the road.
I ended up making everything from 1.52 down negative so that at idle it would pull out fuel. Currently it is set at -.5623 all the way down to 0.
I cut it in half so it is .638 this was so the PCM would allow a lower pulse width. (per slowhawks advice)
I can get some screenshots if needed.
I ended up making everything from 1.52 down negative so that at idle it would pull out fuel. Currently it is set at -.5623 all the way down to 0.
I cut it in half so it is .638 this was so the PCM would allow a lower pulse width. (per slowhawks advice)
I can get some screenshots if needed.