Hanging Rolling Idle

[schaid]

Just got done installing super cobra jet mono blade. Copied all the electronic throttle settings over from a cobra jet tune I have. Driving is awesome. Touchy touchy throttle pedal and I love it. Only issue I'm having is a hanging idle. As I slow to a stop I typically shift to neutral, mt-82 car. As soon as I do that the idle hovers around 1400-1600 until I come to a complete stop, then settles back out to the commanded 1k I have it set to. I've tried using the cobra jet dashpot settings...yeah that didn't work. I've tried with torque based decel on and off, with it on it's even worse, 2500-3000. I've tried playing with the etc throttle angle and the underspeed setting. I can only make it worse not better. I've tried going in the opposite of when I get some sort of response and end up back at 1400-1600 regardless. What am I missing here? I'll post the tune that I had prior to the mono as well as the current one that has the issue. You'll see a majority of the changes are in the electronic throttle tab and in the maf table. Everything else has been working great. Just need help figuring out this issue. ni-12 is the last tune on the twin 60 that was working great. mb-9 is the current that has the hanging issue. Also the cobra jet tune that I've been referencing for settings. Thanks for any help on this matter.

ni - 12.hpt
mb-9.hpt
2013 Cobra Jet 82 degree tune.hpt

[Witt]

Try reducing driver demand engine values at low rpm, low tps points.

[schaid]

Was something I was going to try. Although, I have the same driver demand for both the twin 60 and the scj tb and the twin 60 worked great with those settings.

[schaid]

I sure wish I could log throttle angle. I know I know...it's coming.

[schaid]

I think I'm onto it...whenever tq source is in driver demand it'll idle down, in "tip out limit" it will hang. Now to find where to adjust the settings for that...haven't ran across them yet.

[lxlaw]

Hope ya figure it out...Datalogging and compare are going to totally complete this!!!!

[02reaper]

Have you tried playing with the park/drive idle airflow tables?

[schaid]

Have you tried playing with the park/drive idle airflow tables?

Funny you should mention that. I've been at a friend's son's b-day party all day. He's got less experience tuning than quite a few on the board but understands programming pretty well. He has a cavalier similar in power level to my old one...I digress. He says lemme have a look at it. I hand him the laptop. He says hey Skunk...I go yes...have you tired this park/drive idle airflow tables. I responded with I copied the cj ones over why what's up. He read the description and he claims you could see the lightbulb above my head go off. I set it back to where it was with the twin 60...damn near stalled on the first try. I've been adding 5% at a time until I get the desired, I guess you could call this decay. It's funny though...you posted that about the same time as I came to that realization. Thanks everyone.

Wanted to add this thing is AWESOME!! Throttle response is AMAZING. It's a little touchy, but that's to be expected with a throttle body this large. I'm loving it!!!

[02reaper]

Funny you should mention that. I've been at a friend's son's b-day party all day. He's got less experience tuning than quite a few on the board but understands programming pretty well. He has a cavalier similar in power level to my old one...I digress. He says lemme have a look at it. I hand him the laptop. He says hey Skunk...I go yes...have you tired this park/drive idle airflow tables. I responded with I copied the cj ones over why what's up. He read the description and he claims you could see the lightbulb above my head go off. I set it back to where it was with the twin 60...damn near stalled on the first try. I've been adding 5% at a time until I get the desired, I guess you could call this decay. It's funny though...you posted that about the same time as I came to that realization. Thanks everyone.

Wanted to add this thing is AWESOME!! Throttle response is AMAZING. It's a little touchy, but that's to be expected with a throttle body this large. I'm loving it!!!

Looks like the CJ idles at 1300 rpm also compared to 650 or so for the GT, aside from the cams, and other differences. I would bet that most of the problem is in those tables.

[schaid]

I've got my commanded idle at 1k. The car just seems to "like" that the best. I've messed with it with negative effects. Ok so 1k it is lol.

When I first saw those tables I didn't think much about it. Then on Saturday when I re-read the description of them it just "clicked" it was like dumbass THIS is where you problem IS! Ever since I started adjustments there, everything is back to "normal" for my car...with the exception of a REALLY snappy throttle response and a beauty of a sound coming from under the hood. I love the way na sounds...it's so pure.

Thanks again everyone. I really do appreciate the responses and the suggestions.

I've got it really nice now. Car will hang out at about 1050-1100, never goes lower when I shift to neutral while still moving then settles out REALLY nice at 990-1010. I'm good with that as there where times in the past with the twin 60 while Eric was working through it that I was stalling at almost every stop. He got those issues resolved, I'm imagining those resided in these tables.

[lxlaw]

Which table had the biggest effect on the quick throttle..??

[schaid]

Which table had the biggest effect on the quick throttle..??

Honestly think that's a characteristic of the throttle body itself. I had adjusted some of the tq tables prior to putting the tb on and didn't notice in quicker throttle response. I had a really nice throttle response prior to this throttle body but nothing like it is now.

[ericb027]

So did u put it back to the twin 60 or u use the Cobra Jet file and kept adding %5?

[lxlaw]

Use CJ file with all x y axis and idle airflow as a good start point. Leave TT and inverse stock and leave DD stock. MAF calibration is the most important part and good injector data

[lxlaw]

Don't use dashpot

[lxlaw]

What injectors? I wouldn't even mess with a car if it doesn't have a good injector with good data. Ford Racing, ID, are 2 of the best with data. DW data is hit or miss. If you have a known perfect or close MAF curve you can dial injectors in.

[ericb027]

What injectors? I wouldn't even mess with a car if it doesn't have a good injector with good data. Ford Racing, ID, are 2 of the best with data. DW data is hit or miss. If you have a known perfect or close MAF curve you can dial injectors in.

I got ford racing 47 lb injector do I need get a Calibration?

[lxlaw]

Best place for that data is a Roush cal. Roush use 47's, they are rated at 47's at 3 bar of fuel pressure, at 4 bar, they are 60's. so find an 11-14 Roush blower car and use all the data from that cal. All multipliers and scalars.

[ericb027]

Best place for that data is a Roush cal. Roush use 47's, they are rated at 47's at 3 bar of fuel pressure, at 4 bar, they are 60's. so find an 11-14 Roush blower car and use all the data from that cal. All multipliers and scalars.

I'll get the data in the fuel files but what and what do I get off the Roush data? Like what do i just copy. Thanks I really appreciate your help

[lxlaw]

Everything in the fuel injector data.. all the scalars and all the multipliers