Been fighting trying to tune my cousins T-Type.. Mainly idle, seems BLMs alway change and have big swings.. From a little reading I see that those Turbo Twaek chips force open loop idle, figure this helps the issues but not sure how to do so.. Anyone know?

Also been fighting the off idle stumble which is also inherant with these cars, have tried A/E increase and decreasing, cam sensor advance, MAF table scaling with little help.. Any ideas? Also car does not seem to stumble when open loop as well.. This thing is a PITA to make good.

Car does have comp cam 212/212, 67mm turbo and front mount, headers..

 

Are you trying to use only idle open loop, or open loop all the time?

To force open loop all the time, just raise the coolant enable temp as high as it will go.

I'm not familiar with open loop idle using the '7148.

 

By how much are they swinging, where are your O2's at idle? What chip are you running with that setup? What size are your injectors? If the chip was burned according to that particular setup then I would say look for a broken vacuum line by the fuel pressure regulator. If not, and you turned the cam sensor at least and 1/8th counterclockwise from factory specs to see if that would help tip in, then it's more than likely in the chip. Just have Eric burn you a new one...

 

It's not a Turbo Tweak chip, it is from a stock ACXA bin.. Have checked for vacuum leaks, changes the vacuum block to a billet, new intake gaskets, resealed header gaskets..ect..
80 LB injectors... Have turned the cam sensor atleast 1/8 and did help a lot, but still some there.. Just from some reading it seems that the Turbo Tweaks use open loop idle only.. I am not looking to force open loop always I am aware how to do that, just looking for idle only if able.. Seems the floating BLM at idle is common among the turbo buick crowd from what I read..

 

Eric's chips have open loop idle, but they still have learning capability to keep the mixture right. It doesn't lock to 128, it learns like the other cells, just slower. It sounds like the chip your cousin is running isn't calibrated correctly with those modifications, just have Eric burn you one and be done with it....

 

I have been doing my own since 2002 or so, do all my own of course, and have helped out many others.. I hear great things about the Turbo Tweak guy, but prefer to do it on my own - just my style.. We have the car running and driving great, just fighting some idle issues.. Idles OK, just a little finicky..

Thanks for the advice.. Was just trying to obtain the Open loop idle assuming it will help as it does with "Eric"s.. ANd seems that is what it needs is to learn slower to not over correct itself.. Guess it must be a secret..

 

Got it sorted out today, Most of issue seemed to be post turbo o2 sensor and slight leak in downpipe that was undetected.. Also did free air calibration on WB, being he is using NB output from.. Actually response is great finally, BLM seem very stable today after some little scaling of MAF 1,2,3 tables.. Have AF locked in at 11.6-12.1 with 15lbs.. Hope to get car to track, then crank up boost..

Now have GN1R heads to install over winter.. SHould be very strong..

 

Great news.. To any who have followed this at all, I have contacted TunerCat - They have updated the T31 deffinition to allow closed loop idle and learn control functions! Win for the DIY guys I suppose.

 

Just curious..could this code be modified for V8 applications?

 

I think the Super Aujp give that functionality for Open loop idle..