87 T/A with a 305 TPI and 700R4. when I leave it in a low gear like 1st, and I punch it to shift at the yellow line, I sometimes notice a big loss of power over 3500 RPMs. What could cause this? Timing? Some days it runs strong, some days i lose a lot of power and its like a slug.

It has new platinum plugs, msd 8mm wires, new fuel filter, screens removed from MAF, flow booster on throttle body, and a conicle K&N filter where the stock airbox was and a stock 3" y pipe and cat w/ dynomax catback, underdrive pulleys, and i removed the belt from the smog pump. It is getting enough air in and out, but could it be starved of fuel? Sometimes it did this before these mods when it was bone stock.

 

There is a similar post below. My car has same symptoms. One day it feels like it is 100 HP more and other feels much weaker.

I do not know what it might be. It could be false knock retarding our timing.

Do you have headers?


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89Iroc, 305 TPI, WC T5, 3.08 Posi, Headers, Hooker Y-Pipe, 3 inch over the axle, Flowmaster 80, No Cat, Aluminium Driveshaft, Ported Plenum, Air Foil, K&N, AFPR, All free mods,