We are having a lot of problems with our idle surging....to the point that it is stalling. We have read just about everything in this forum (very helpful, by the way) and we are now considering recalibrating the computer. How does one go about doing this? It is a 95 Ford Mustang GT with many modifications. Help?
Computer Recalibration?
- Thread starter wingnut1192000
- Start date
TrueBlue95GT
Member
The only way to do anything about the computer is to either get a chip or an eec tuner like the tweecer or PMS. You can't recalibrate our computer.
I just had a car dyno tuned with a Superchip....Very impressive..came out with 80 more RWHP then we went in with...399.99 for the dyno time and chip..
read this months 5.0, an article called "fine tuning"....this software can do some amazing stuff...i witnessed it first hand.....
nothing against the Tweecer as I almost went that route...but there is a learning curve....for 400.00 it can be a done deal with a chip, since it reads like your modded and ready for a final tune....
the guys i went to know Fords, and that made a big dif....they mentioned they have there fare share of cars come in not running...soon as they hooked in the EEC they can see this problems...
Im sold on the chip, would love to spend a week with these guys, its amazing what they can do....
Did you do the complete idle set-up from scratch???
read this months 5.0, an article called "fine tuning"....this software can do some amazing stuff...i witnessed it first hand.....
nothing against the Tweecer as I almost went that route...but there is a learning curve....for 400.00 it can be a done deal with a chip, since it reads like your modded and ready for a final tune....
the guys i went to know Fords, and that made a big dif....they mentioned they have there fare share of cars come in not running...soon as they hooked in the EEC they can see this problems...
Im sold on the chip, would love to spend a week with these guys, its amazing what they can do....
Did you do the complete idle set-up from scratch???
Thanks for the info, we will definately look into it. I will let you know. And yes, we did the idle set up from scratch. At this point, it is driving us crazy because we have tried everything and we cannot get the car running properly. We have a GTech in the car and it is telling us that we are doing the 1/4 mile in 13.57 at 106 MPH. That is crazy considering everything that is done to this car. We were hoping that maybe the GTech is wrong, but the car is running horrible! Thanks again for the advice.
The car is surging really badly to the point of stalling. I have replaced everything in the car! I have put the 345 hp ford racing engine, 30 lb injectors, 75mm maf cold air induction, 70mm throttle body, 410 gears, flow master cat back exhaust with off road h pipe, new tps, new iac and rpm jr upper and lower intake. I thought maybe it was electrical because it stalls if you turn the steering wheel at an idle or if you press the window button, but it doesn't seem to be a ground either. I was thinking that maybe the computer is causing the problem because of so many mods done to the car.
wingnut1192000 said:
You have several things going on that most likely is causing the t4m0 to go nuts.
The maf is caled for the 30lb inj's I would assume. If that is the case then your load reference point at idle has moved (which hoses with the fuel & spark tables btw) but the maf is trying to meter air with the cheat method and the whole thing at idle is just totally screwed. With 24lb inj's the error at small pulse widths is not so bad that you can, most of the time, get by but with those 30's the small pulse width conditions just dump too much fuel.
The cai setup can hose with low airflow (idle conditions) and cause trouble as well. I changed mine to a straight shot by removing a 90 degree bend in the fender and had to tweec the inj & maf values a bit to get back my steady idle after the cai change.
Your new combo is now pulling so much more air at idle due to the new parts but the values in the pcm are still expecting the amount of air that a stock 302 would use.
You can self tune with various tuning interfaces or get a chip but IMHO based on my findings with the t4m0 I don't think you can expect your pcm to LEARN its way around all of your changes.
My car would barely idle, stall a stop signs, idle way too rich, surge at low speeds, buck at cruising speeds, and all of the other stuff I'd be willing to bet you are dealing with at this time. I finally moved from the t4m0 (GT cal file) to the j4j1 (Cobra cal file) which is a better place to start tuning from due to it having values already in place for larger inj's, heads, cam, and the like.
Later
Grady
wingnut1192000 said:
The 94-95 Mustang GT & Cobra uses a pcm (powertrain control module) or computer that is from the same family. The hardware is the same but the calibration file or cal file is different. The GT uses the t4m0 file and the Cobra uses the j4j1 file.
In the other post I told you that I moved to the j4j1.
To make things more understandable I should say that I loaded the cal file that comes in the Cobra pcm into my original GT pcm which basically makes my 95GT pcm the same pcm that is in a 95 Cobra.
Hope that helps!
Later
Grady
They are in your area(Vineland to be exact) and use a mustang dyno 
http://www.thinkfastmotorsports.com/
http://www.thinkfastmotorsports.com/wytstang said:They are in your area(Vineland to be exact) and use a mustang dyno
There you go
Good thing about Stangs is you don't have to look too hard for help
Later
Grady
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