Backfire

[GJP05]

Jim,

I'm still having backfire issues with my car. It is only on deceleration, and with the car in gear. If I decelerate with the clutch engaged I do not get the backfire. I already changed my plugs and looked for an exhaust leak. Any other ideas?


Greg

 

[JimIII@JDM]

It sounds like normal exhaust backpressure to me, with out hearing it in person. Can you video the sound? You should have a descent amount of popping coming from the exhaust on decel. As long as its not popping and backfiring on acceleration its not an issue. Its depending on the mid pipe and exhaust combination as well as fuel on decel. We have some extra fuel commanded on decel to keep everything cooled down a little.

 

[GJP05]

I have the Kooks LT headers and catted x-pipe. If that is normal under deceleration then I'm not that worried about it. I still have issue when the car is near stopping that the rpms drop to about 400 and the car almost wants to die. This is during deceleration or idling at a light. I didn't notice either of those issues before the GT500 throttle body and new tune I got from you. The old tune worked fine and I think the only thing added was the throttle body.

 

[JimIII@JDM]

I have the Kooks LT headers and catted x-pipe. If that is normal under deceleration then I'm not that worried about it. I still have issue when the car is near stopping that the rpms drop to about 400 and the car almost wants to die. This is during deceleration or idling at a light. I didn't notice either of those issues before the GT500 throttle body and new tune I got from you. The old tune worked fine and I think the only thing added was the throttle body.

Have you tried just throwing the stock throttle body on with the new tune to see if it helped any with the idle? I dont usually see problems with the idle dropping too low with the TB installed sometimes its a touch too high, your just the opposite?? Let me know if you can get a sound clip of the cars exhaust

 

[GJP05]

Jim,

I swapped to the stock throttle body and the hesitation is gone. Also there is no more backfire. Before I swapped the throttle seemed to jump all over the place while driving and the response was very slow.


Greg

 

[JimIII@JDM]

Thats funny it sounds like it could have been running a little lean from the throttle body then. Giving you a lean tip in stumble and lean pop on decel.

 

[GJP05]

Jim,


I replaced the TPS but I'm still having the same issue with the car going into fail safe when trying to give it too much throttle. The pedeal sensors will say the thottle is at 70% but the throttle reads 30%. Any other ideas what it might be?


Greg