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Jerking, sputtering, popping, surging, after hci install

  • Thread starter Thread starter Strype
  • Start date Start date Aug 10, 2010

Strype

Cuthbert catcher
Founding Member
May 11, 1999
61
34
104
Huntsvegas, AL
Aug 10, 2010
#1
  • Aug 10, 2010
  • #1
For reference...

Problem:
Got the motor back together and the car wanted to jerk and surge while driving at 2000 rpm. I thought it was the new cam.



1993 LX Notch
5 speed
66k miles
Heads/Cam/Intake
stock fuel pump
stock injectors



Solution:
After speaking with guys on Stangnet, I remembered the Fuel Analyzer at mustangworks.com (not a plug for them, but they have a good analyzer). It told me that I needed a minimum 120lph fuel pump and the 19lb injectors needed to be bumped up to 60 psi, and not to exceed 80 psi. The stock is 95 lph. With the guidance of WHT306, we changed the stock fuel pump to a 190lph. The stock injectors are still on there so we bumped them up to 60 psi.




Aftermath:
The car is 100% different. The throttle response is better. The suging and jerking is gone for the most part. The popping through the exhaust is gone except for a small leak on the right bank. We used an iphone app to dyno the car (gives a ballpark figure) and it read 294hp at the wheels.




I'll update when we put the 24lb injectors on. The moral of the story is this: If you mod the car, you need to mod the fuel pump.
 
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