Miss at Part Throttle ... Need Help

Discussion in 'General Tech' started by domhoff13, Dec 30, 2014.

  1. domhoff13

    domhoff13 New Member

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    Pittsburgh, PA
    Hi,

    I am currently lost and I do not want to be throwing money at this thing left and right and have it being something simple. I am having an issue with a part throttle miss under any load however at or full throttle (WOT) or sitting in the drive way I am not experiencing it. Car ran fine until one day after some rain would not start and when it did this issue started after it fired up. Also if I disconnect the MAF the car runs fine full power no issues. I have been trying to diagnose this issue for a while but what I thought was going to fix it did not work.

    As far as modifications done to the car I know for a fact that it is at least a 351W that is 0.030 (saw from a bore scope) over it could be a stroker but I am not sure as the previous owner did not know. TrickFlow Twisted Wedge heads, Crane 1.7rr's, unknown cam, SVO lower intake, Comp Polymers Upper Intake, SVO elbow, 30 lb inj., MSD 6AL, Accel TFI coil / MSD Street Fire coil

    1. New Parts - Plugs, Ford Racing wires, Accel Coil, cap, rotor, fuel filter, multiple ICM's, PIP or stator, IAC.

    2. I have checked the continuity and voltage on the MAF it was reading low at .7v at idle and it had a steady increase as throttle was increased no issues that I could visually see Pro-Flow 70mm calibrated for 30lb inj.

    3. The Air Charge Temp sensor had low voltage to it maybe 3.5v not 5v which the book calls for???

    4. Check timing and set at 10* and bumped up to 14* no change (was initially set at well over 20 for initi
    al from P.O.) checked with Spout out

    5. Fuel Pressure 35psi at idle as the throttle is cracked it drops to roughly 30psi then spikes to 39psi.