Start up and idle issues since 98/99 ecu install

[dsmarmy777gst]

I have a 97 GST and a little over a year ago I bought a flashable ecu tuned by Jeff at DSMchips. Ever since i've installed this thing i've had rough idle issues. The car acts like it wants to die most of the time. Also when I go to start it up I have to give it a little gas or else it dies instantly.. Any ideas on something I may have to change in the tune? Mods in the profile are all up to date if it matters.

Also I should mention my buddy had the same issues when he installed a flashable ecu in his 97 Spyder.

 

[mike96]

So lets see if I am reading your profile correctly... You have a flash-able ECU tuned by Jeff... An ECU+ piggyback tuner... And a MAFT... Sounds to me like you have too many things trying to do the same job... First I would get rid of tha MAFT, if the ECU+ is capable of doing what the MAFT does that why do you need it? After you do that I would seriously think about ditching the ECU+ as well. From the quick reading that I did on the ECU+ page there is almost nothing that it does that Ceddy has not incorporated into the flash-able ECU code (MAFT translation is about it)... And if you want to one up that setup Ceddy has incorporated speed density so you can get rid of the GM MAF all together and go with just an inlet temp and map sensor. Actually I take that back ditch the ECU+ first and keep the MAFT for the time being then later when you decide to you can go SD and ditch the MAFT/GM all together. I am willing to bet that for what you will get for the ECU+ alone you can afford to buy the hardware you need to flash the ECU yourself.

Is your friends setup the same as yours, ECU+ and all?

 

[antilag]

I agree with mike, that you have too many things fighting each other that isn't taken into account in the ecu. My guess is that your low ltft is pegged. I would make sure your maft is set to a 2g maf and all the adjustments for low are at 0. Let the ecu do the work as long as it was set up for your 750 injectors.

 

[estoyaqui30]

I'm running a 99 H8 ECU tuned by Ceddy directly. I have removed all other tuning devices and the car ran wonderful from the second it started. I was using ECU+ before that and a SAFC II before that. I think that you can't run too many different systems at the same time, because they will conflict.

 

[92AWDHX40]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

 

[dsmarmy777gst]

So lets see if I am reading your profile correctly... You have a flash-able ECU tuned by Jeff... An ECU+ piggyback tuner... And a MAFT... Sounds to me like you have too many things trying to do the same job... First I would get rid of tha MAFT, if the ECU+ is capable of doing what the MAFT does that why do you need it? After you do that I would seriously think about ditching the ECU+ as well. From the quick reading that I did on the ECU+ page there is almost nothing that it does that Ceddy has not incorporated into the flash-able ECU code (MAFT translation is about it)... And if you want to one up that setup Ceddy has incorporated speed density so you can get rid of the GM MAF all together and go with just an inlet temp and map sensor. Actually I take that back ditch the ECU+ first and keep the MAFT for the time being then later when you decide to you can go SD and ditch the MAFT/GM all together. I am willing to bet that for what you will get for the ECU+ alone you can afford to buy the hardware you need to flash the ECU yourself.

Is your friends setup the same as yours, ECU+ and all?

Yes he also uses the ecu+ piggyback. The car did this before I installed the ecu+. The only way i can use the gm maf is with ecu+. No translator at all. I only use the ecu+ because i'm new to tuning and still haven't got it all figured out. Its much easier with a piggyback at this point. Although i do not use ecu+ for fuel, timing, limits, etc. Simply just for its maf translating and boost control abilities.. That being said I do plan to do away with it in the near future and just run speed density once i get it all figured out. And yes I already have a flash cable. I know how to use ecuflash for the most part, but logging with evoscan is for shit in my opinion. I honestly think once i go speed density itll solve many problems. At this point, the gm maf, and my pos 274 regrinds have most to do with any idle issues.

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

I was going to say, i've used 3 different throttle bodies on this car since ive had it and its always been the same. But i have used the same ISC. So ill steal it off my other gst and see how it goes!

I'm running a 99 H8 ECU tuned by Ceddy directly. I have removed all other tuning devices and the car ran wonderful from the second it started. I was using ECU+ before that and a SAFC II before that. I think that you can't run too many different systems at the same time, because they will conflict.

I wish I could remember exactly when it all happened. I also had an SAFC II before the ecu+, but i dont remember how it ran