05 Surges and dies on idle >HELP!!!!!!!

240boost · 10-15-2007, 08:53 PM

I have a 205 mustang GT with a manuel tranny > I have purchased a sct tunner from Dallas mustang and had the steeda tune installed and instantly the surge started . The car never had a problem idleing an drove fine until the first tune . Anyway I returned the sct and purchased 14" bar brakes and sportline sprins and the steeda dlete plate. I also purchased a Velocity vortech supercharger kit and instaled it this weekend . It runs like a bat out of hell and I thought the new tune from JMS wouldfix the idle problem but it got worse and now it dies at times . Has anyone had this problem?
I have heard that a bad alternator can cause this along with a computer on the car!
Help!~!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! . I hate having my car messed up!!!!

STANGER_SC · 10-25-2007, 06:03 PM

I been there with the Surge problem....Many know that. Could be a multitude of factors but you will NOT tune that out. If you start at idle and slowly rev it, increasing the RPM, does it cause the rough idling and seems like it starts misfiring? If so you will need to take it to a Ford Dealership and pay for a complete diagnostic. They have the ability to do a more complete diagnostic than any speed shop will. The alternator will go bad but something has to cause that. I had to have the alternator replaced but the main problem was the computer itself was bad. Caused by an electrical short according to the dealership that replaced it.

Replaced the PCM, ECU and alternator and the surging is gone but my engine light still stays on even when I clear the codes. But I really dont have any significant performance problems otherwise anymore. Of course you will definitely need a custom tune. Did you install your blower?
Good luck I hope it gets worked out soon for you. It is a Gremlin that will haunt you until you get it diagnosed properly.

240boost · 10-25-2007, 07:52 PM

Well its just poor tune ! Canned tune or gineric> I did the install and consider myself no amature in mechanics . I can't rely on myself because I' not a tunner with sct . I have checked everything and the perameters of deleet plates are all jacked up . I got the car to idle at 850 rpms with the tunner set to idle at 1350 in drive and 950 in neutral. Now the car runs and drives fine . It's not a leak or injectors or vacume its just a cheap tune sent over the intranet> suck almost pulled my hair out but I have a pasion for hot rods and HP . More to come and I'm sure hardships with fun!!!

Snake 42 · 11-02-2007, 02:43 PM

Quote:

Originally Posted by 240boost

Well its just poor tune ! Canned tune or gineric> I did the install and consider myself no amature in mechanics . I can't rely on myself because I' not a tunner with sct . I have checked everything and the perameters of deleet plates are all jacked up . I got the car to idle at 850 rpms with the tunner set to idle at 1350 in drive and 950 in neutral. Now the car runs and drives fine . It's not a leak or injectors or vacume its just a cheap tune sent over the intranet> suck almost pulled my hair out but I have a pasion for hot rods and HP . More to come and I'm sure hardships with fun!!!

Is your car a stick or automatic? Why the high idle numbers? My 06 GT with automatic idles at 650 both in gear and in neutral. With a high idle you are killing a small bit on throttle response and using more fuel. No criticism, just curious.

Snake 42

Agent Jones · 11-02-2007, 03:07 PM

Quote:

Originally Posted by 240boost

I have a 205 mustang GT with a manuel tranny

Its a stick....

Snake 42 · 11-07-2007, 11:49 PM

Quote:

Originally Posted by 240boost

I have a 205 mustang GT with a manuel tranny > I have purchased a sct tunner from Dallas mustang and had the steeda tune installed and instantly the surge started . The car never had a problem idleing an drove fine until the first tune . Anyway I returned the sct and purchased 14" bar brakes and sportline sprins and the steeda dlete plate. I also purchased a Velocity vortech supercharger kit and instaled it this weekend . It runs like a bat out of hell and I thought the new tune from JMS wouldfix the idle problem but it got worse and now it dies at times . Has anyone had this problem?
I have heard that a bad alternator can cause this along with a computer on the car!
Help!~!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! . I hate having my car messed up!!!!

You didn't say if you returned your Stang to the original factory tune before you returned the SCT. If not then it's possible that any other tunes you add can be corrupted by the SCT tune that was left installed. I'm not positive but I think any parameters not addressed by the JMS tune would remain as they were when the SCT tune was installed.

Snake 42

240boost · 11-08-2007, 07:34 PM

Yeah I installed the factory tune and it all stayed the same .

10-15-2007, 08:53 PM	#1
240boost Registered User Join Date: May 2007 Posts: 57 Trader Rating: (0)	05 Surges and dies on idle >HELP!!!!!!! I have a 205 mustang GT with a manuel tranny > I have purchased a sct tunner from Dallas mustang and had the steeda tune installed and instantly the surge started . The car never had a problem idleing an drove fine until the first tune . Anyway I returned the sct and purchased 14" bar brakes and sportline sprins and the steeda dlete plate. I also purchased a Velocity vortech supercharger kit and instaled it this weekend . It runs like a bat out of hell and I thought the new tune from JMS wouldfix the idle problem but it got worse and now it dies at times . Has anyone had this problem? I have heard that a bad alternator can cause this along with a computer on the car! Help!~!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! . I hate having my car messed up!!!!

10-25-2007, 06:03 PM	#2
STANGER_SC MonsterFishKeeper Join Date: Mar 2007 Location: SA Texas Posts: 222 Trader Rating: (1)	I been there with the Surge problem....Many know that. Could be a multitude of factors but you will NOT tune that out. If you start at idle and slowly rev it, increasing the RPM, does it cause the rough idling and seems like it starts misfiring? If so you will need to take it to a Ford Dealership and pay for a complete diagnostic. They have the ability to do a more complete diagnostic than any speed shop will. The alternator will go bad but something has to cause that. I had to have the alternator replaced but the main problem was the computer itself was bad. Caused by an electrical short according to the dealership that replaced it. Replaced the PCM, ECU and alternator and the surging is gone but my engine light still stays on even when I clear the codes. But I really dont have any significant performance problems otherwise anymore. Of course you will definitely need a custom tune. Did you install your blower? Good luck I hope it gets worked out soon for you. It is a Gremlin that will haunt you until you get it diagnosed properly. __________________

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10-25-2007, 07:52 PM	#3
240boost Registered User Join Date: May 2007 Posts: 57 Trader Rating: (0)	Well its just poor tune ! Canned tune or gineric> I did the install and consider myself no amature in mechanics . I can't rely on myself because I' not a tunner with sct . I have checked everything and the perameters of deleet plates are all jacked up . I got the car to idle at 850 rpms with the tunner set to idle at 1350 in drive and 950 in neutral. Now the car runs and drives fine . It's not a leak or injectors or vacume its just a cheap tune sent over the intranet> suck almost pulled my hair out but I have a pasion for hot rods and HP . More to come and I'm sure hardships with fun!!!

11-08-2007, 07:34 PM	#7
240boost Registered User Join Date: May 2007 Posts: 57 Trader Rating: (0)	Yeah I installed the factory tune and it all stayed the same .