Start up before tune stumble. Normal or not?

VA-Mach1

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Installed a Vortech V3 Si on my 99 GT. Started the car and everything is good until 1500 RPM when the motor starts to stumble as if missing when gradually applying throttle. It does not clear up with more throttle. It will stall out if I give it more throttle. If I blip the throttle it will quickly go to 2000 or 2500 RPM and drop back down as normal. I don't want to push it to much before a tune. Just wondering if this is normal before a tune. Did a Google search but didn't come up with much. I'm in the process of scheduling a dyno tune now.

Any input from experience would be welcome. Thanks

Setup is:
Vortech V3
BBK 78mm Throttle Intake
CXRacing Air to Air Intercooler W/Bypass Valve piped back into intake before supercharger
Ford Lightning 42LB Injectors OEM Ford
Ford Lightning 90mm MAF OEM Ford before supercharger
DeatschWerks In-Tank Fuel Pump 340 LPH
NGK TR6 @ .030
 

VA-Mach1

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Do you have a start up driveability tune in it? If not it's not going to run right.

No. I emailed my tuner. Was told since I'm using the OEM Ford Lightning injectors and MAF I would be able to start and drive the car without a startup tune as long as I stay out of boost.

Which the car does start and runs just fine until 1500RPM. I"m trying to get back in contact with the tuner also about this issue. If this is normal before a tune then I'll just baby the car for the 7 mile drive to the dyno. If it's not normal I need help with which component to start checking.
 

blownstang4.6

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No. I emailed my tuner. Was told since I'm using the OEM Ford Lightning injectors and MAF I would be able to start and drive the car without a startup tune as long as I stay out of boost.

Which the car does start and runs just fine until 1500RPM. I"m trying to get back in contact with the tuner also about this issue. If this is normal before a tune then I'll just baby the car for the 7 mile drive to the dyno. If it's not normal I need help with which component to start checking.

It's normal because you don't have a tune on it for the changes you made. You shouldn't be driving it until you get a startup tune. I'd be hesitant driving it 7 miles unless you want to get there and end up changing plugs or 02 sensors. Not sure why tuners are telling people they can just start the car and drive it after changing fuel and air components without making the revisions to match in the tune. Shouldn't take more than a few minutes for your tuner to create you a startup driveability file.
 

VA-Mach1

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It's normal because you don't have a tune on it for the changes you made. You shouldn't be driving it until you get a startup tune. I'd be hesitant driving it 7 miles unless you want to get there and end up changing plugs or 02 sensors. Not sure why tuners are telling people they can just start the car and drive it after changing fuel and air components without making the revisions to match in the tune. Shouldn't take more than a few minutes for your tuner to create you a startup driveability file.


Yup. I'm trying to get in contact with the tuner again. He takes some time to email back.

I pulled some spark plugs today and they are black. Looks like it's running way to rich. And it set off my CO alarm in the garage with all the doors all open.

I'm not going to attempt to drive it like it is. I need a start up tune. It's just not working as is.
 

01yellercobra

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No. I emailed my tuner. Was told since I'm using the OEM Ford Lightning injectors and MAF I would be able to start and drive the car without a startup tune as long as I stay out of boost.

Which the car does start and runs just fine until 1500RPM. I"m trying to get back in contact with the tuner also about this issue. If this is normal before a tune then I'll just baby the car for the 7 mile drive to the dyno. If it's not normal I need help with which component to start checking.

I'd find another tuner. That's just ignorant.
 

VA-Mach1

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I rechecked everything today and found the CXRacing bypass valve was staying closed. I removed one of the springs and adjusted it. Then used my X4 to change to 36lb injectors. That's the largest setting it has. The car runs WAY better now. Good enough I can drive it to the tuner.

P.S. Checking on another tuner also.
 

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