Why does my car keep dying at idle?
Why does my car keep dying at idle? Hey folks, I just did a torquer V3 install on my 99 A4 ls1. I just got HP tuners to do the tune for it and i'm having great luck so far with everything EXCEPT the idle.
I know I have a lot more playing to keep the rpms from hunting or surging at idle and thats fine. My problem is, when the engine is cold the car starts great (first crank everytime) but will immediately die. I HAVE to give it 5% throttle (1200 rpms ish) for about 2 minutes until it gets warm. THen when I let off the rpms drop to like 400 and MAYBE it'll live, maybe not.
WHen the engine is hot, it starts up really well and only dies sometimes. When I make sharp turns at low speeds or if i come to a stop at a light it'll die usually.
So is this completely tuning? Is it mechanical?
What should I look for? I'm not throwing any DTC's at all and the car runs great otherwise.
I know I have a lot more playing to keep the rpms from hunting or surging at idle and thats fine. My problem is, when the engine is cold the car starts great (first crank everytime) but will immediately die. I HAVE to give it 5% throttle (1200 rpms ish) for about 2 minutes until it gets warm. THen when I let off the rpms drop to like 400 and MAYBE it'll live, maybe not.
WHen the engine is hot, it starts up really well and only dies sometimes. When I make sharp turns at low speeds or if i come to a stop at a light it'll die usually.
So is this completely tuning? Is it mechanical?
What should I look for? I'm not throwing any DTC's at all and the car runs great otherwise.
Have you tuned the fueling with a wideband? You have to get the AFR, timing, and running airflow right for it to idle properly. You will have to open the throttle blade more (and do a TPS reset) as well.
I don't have a wideband hooked up yet, i was just doing some PT and idle tuning so far.
I already cracked the throttle about 4% and did a TPS learn (HPTuners shows it at 0% so it worked).
DO you think that proper A/F tuning will fix that problem? Should I play with the throttle cracker/delay settings?
I already cracked the throttle about 4% and did a TPS learn (HPTuners shows it at 0% so it worked).
DO you think that proper A/F tuning will fix that problem? Should I play with the throttle cracker/delay settings?
Get the car to full hot idle. Adjust the TB until you get about 50-70ish counts on the IAC (with the TPS reading 0%). After that, do your Park/neutral and in-gear idle airflow logging. You will have to fine tune it later but that will yield the largest improvement. Unless things are way off; your idle should be pretty solid after that. If your MAF/VE are not yet tuned, make sure that you have closed loop enabled. The area beneath it's operation will change once your MAF and VE are tuned, so keep that in mind.
I read that if I get the IAC counts in line using the TB screw and the TPS voltage is above .6, that's bad. My IAC counts are in line, but I'm at .78v on the TPS voltage (TPS 0% though).
It's getting better, I just started and it started up and alllllmost held idle. On the second start it was great.
This is pretty stupid but how do I know if I'm in OL or CL without forcing it into one or the other? What parameter tells me that?
Thanks for the help for a newbie tuner guys.
It's getting better, I just started and it started up and alllllmost held idle. On the second start it was great.
This is pretty stupid but how do I know if I'm in OL or CL without forcing it into one or the other? What parameter tells me that?
Thanks for the help for a newbie tuner guys.
Look for moving STFTs (vs sitting at 0) to tell you that you ar ein CL, or add the CL status bit.
Get the car to FULL hot idle before adjusting the TB. Not close, not almost; make it about 200degF. You can reach the top end of the posted range. As long as the TPS resets to 0% without doing that 0-1% flicker, you are good.
Get the car to FULL hot idle before adjusting the TB. Not close, not almost; make it about 200degF. You can reach the top end of the posted range. As long as the TPS resets to 0% without doing that 0-1% flicker, you are good.
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Most of the time, if your idle airflow is right, and it still wants to stall when hot, it's either too much fuel, or not enough spark, or a combo of both. Tune the fueling first. Set your spark tables up so your idle spark is around 22-24 degrees.
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