Haltech Driveability Issues
06-23-16, 10:10 AM
#1
Driveability Issues
Hey I have had a couple issues with the driveability of my car for the last few years and have been chasing my tail learning to tune the car myself.
My first issue which I think is just a issue with a setting is the Zero throttle Injection doesnt work when the temps are high. I dot mean like the car is going to over heat but on hot days when I have zero throttle the injectors keep there normal injection time instead of zero-ing. Its killing my mpg and at highway speeds/ high rpms I can see the cloud of unburnt fuel from the exhaust.... This is only an issue when its hot on the same drive if temps go down it works normally.
My second issue is the engine load transition isnt smooth at sub 4000 rpm. I know its not my tps cause I can do a load sweep just clutching the engine and the AFRs spike and the car lugs.
Car is s5 turbo woth Sprint RE.... its been my daily for 4 yrs.
My first issue which I think is just a issue with a setting is the Zero throttle Injection doesnt work when the temps are high. I dot mean like the car is going to over heat but on hot days when I have zero throttle the injectors keep there normal injection time instead of zero-ing. Its killing my mpg and at highway speeds/ high rpms I can see the cloud of unburnt fuel from the exhaust.... This is only an issue when its hot on the same drive if temps go down it works normally.
My second issue is the engine load transition isnt smooth at sub 4000 rpm. I know its not my tps cause I can do a load sweep just clutching the engine and the AFRs spike and the car lugs.
Car is s5 turbo woth Sprint RE.... its been my daily for 4 yrs.
07-06-16, 05:47 PM
#3
I can't answer your specific question, but there is no reason to use zero throttle mapping. It's only use is with engines that produce very low vacuum at idle and can't be mapped with MAP alone. Disable the feature and use the base fuel map. It will provide more resolution and accuracy.
07-08-16, 09:52 PM
#4
I can't answer your specific question, but there is no reason to use zero throttle mapping. It's only use is with engines that produce very low vacuum at idle and can't be mapped with MAP alone. Disable the feature and use the base fuel map. It will provide more resolution and accuracy.
07-09-16, 07:21 AM
#5
Ok. Is the throttle actually returning to 0? What is the closed throttle threshold set to? What is the throttle dead band set to?
Even if the fuel cut was working, you should lean out the high vacuum areas of the fuel map so that they're not so rich and run an appropriate mixture when used.
Even if the fuel cut was working, you should lean out the high vacuum areas of the fuel map so that they're not so rich and run an appropriate mixture when used.
07-10-16, 04:52 PM
#6
can you post your map? what size are your injectors? just a general fuel tuning tip.. idk if there is a better way, but the way i tune the fuel map is at a single RPM at different load points.. like cruise at 3000rpm, and try to tune each load point to whatever AFR you want for only 3000rpm, working from high vacuum up to max boost. whatever values you come up with at 3000rpm, will be close at all other RPM ranges, so just copy that for all rpms. then pick a different RPM and recheck. the map in vauum ends up being curved up to 0 psi, then in boost, i just tune linearly. In boost the fuel map looks like straight line, i really only use 4 load points in boost and linearize in between
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