popping back threw the intake

[cobra0393]

I just got my car running a few days ago, and i drove it today for the first time. When i give gas in the lower Rpm it pops back threw the intake and when it gets above about 3000rpms it pops also. I cant fiqure out why its doing this. Any advice.
Thanks
Jamey

 

[93Cobra#2771]

Sounds like a timing issue, or a lean condition. Do you have some bucking as well? I would check for vacuum leaks first...

 

[LEE93COBRA]

Another vote for timing

 

[cobra0393]

I've double checked the timing, Yes the car is bucking. The supercharger is so loud that i cant hear any vacum leaks, but it idles perfect. The car has a speed pro computer system, could it be something electrical.

 

[93Cobra#2771]

Definitely in your tune. Who set up your tune with the speed pro system? They should be willing to rework the tune until it is right (assuming you haven't changed anything since the tune was done).

You can't hear all vacuum leaks - you should check by the unlit propane torch method, or wd40 method, or whatever you are comfortable with.

I don't know your combo, but it could be a lot of things. And bucking is usually from a lean condition. I would not hammer on the car until you get this stuff sorted out...

 

[cobra0393]

I've finally fiqured it out. On a DFI car you have to set the timing at total advanced, i didnt know that. So i had the timing set at 13 degrees, I put it on 30 degrees for now until i can get the car on the dyno and get the proper tune. Im SLOWLY but surely learning how to tune a DFI car

Thanks for the help 93cobra2771 and LEE93COBRA

 

[93Cobra#2771]

Careful with that much advance and a blower. Unless, of course, the DFI system has a boost reference pulling out total advance. You will pop a HG in a second with that much timing and a blower.

So you run spout out or what?

 

[cobra0393]

Im being easy on the car until i get it tuned. This speed Pro kit doesnt use a spout the engine wiring harness is completly deferent from a stock one.

 

[mustangdan429]

Careful with that much advance and a blower. Unless, of course, the DFI system has a boost reference pulling out total advance. You will pop a HG in a second with that much timing and a blower.

So you run spout out or what?

whats a HG?

 

[cobra0393]

HG is short for head gasket

 

[mustangdan429]

oh ok

 

[93Cobra#2771]

This speed Pro kit doesnt use a spout the engine wiring harness is completly deferent from a stock one.

In that case, you definitely need to do some serious tuning work. You or your tuner, that is...

What are your HP levels? Why did you change the EFI system to Speed Pro?

 

[cobra0393]

The car already had the speed Pro on it,( i would rather have the stock computer). The car should make 500 - 600 to the tires. I would prefer a professional to tune the car for me, but i cant find anyone to do it. Do you know anyone.

 

[331 LX]

The car already had the speed Pro on it,( i would rather have the stock computer). The car should make 500 - 600 to the tires. I would prefer a professional to tune the car for me, but i cant find anyone to do it. Do you know anyone.

Jamey Check your Private messages.

I'm not sure if you like Delk or not but I wonder if they can tune it? I have heard good and bad about them but no personal experience.

 

[93Cobra#2771]

Another possiblity is AFM, but they are in Illinois, I believe.

Go over to www.stangtuning.com and throw a post up in there. Someone may be able to help you out. The trick is going to be finding someone who is familiar with that system...

 

[331 LX]

Another possiblity is AFM, but they are in Illinois, I believe.

Go over to www.stangtuning.com and throw a post up in there. Someone may be able to help you out. The trick is going to be finding someone who is familiar with that system...

Yea i told him last night to check out Stangtuning.com

 

[cobra0393]

Ive already called AFM, they wont tune a DFI car. They tuned my other car, but it has a PMS system on it.
Someone told me told me to call Modular Depot and see if they would tune it.

 

[93Cobra#2771]

Is your factory harness still in the car? How hard would it be to convert back to A9L? If it would be bad to do, there is no reason why you can't tune your car with the factory processor and a chip/tuner. Plenty of cars out there with your HP level are doing the same. You could sell your DFI and prob come out ahead if you went that route...

 

[cobra0393]

The whole passenger side harness has been removed, but it still has the rest of it. That is a good idea, i might end up doing that.

 

[93Cobra#2771]

Unfortunately, it may be your only option if you can't find someone to tune the combo for you...