low power in low RPMs(Few Questions)

:bang: I've searched and can't find an aswer, so I bring it to the table. I have a Manual 1987 Mustang with a 1990 5.0 in it.

I can't get a nice jump off the line during a race and a burnout is almost impossible for me at this point. I should at least be spinning the tires off of my jump during a race, but I don't. It seems as if my car is not producing enough power in the lower RPM range. From 1-2k it has nuthing, but right above 2k, I feel the power pick up then my car starts to move. I have done a full tune up, and checked just about everything, my car seems to be flawless, but it doesn't run that way.

Another problem that has occured recently is when I'm driving, for example in 5th gear, the RPMs will rise about 200-300, I wont go any quicker, it actually seems as if Im slowing down, but then it ctaches and goes back to normal. My foot is no where near the clutch...

-- Now I do have a 1990 ECU in the car, the ECU came from a car which had an automatic in it, would that be the cause of some of this maybe? I havn;'t had any of these problems until 2 - 3 weeks ago

If anyone has any ideas, about either problem I'd appreciate anything I can get at this point. Thank you.
 
yea you should probably get the right ecu - get the A9L - what wiring harness did you use, did you use the 90 wiring harness w/ the Auto?? or the 87 harness, and justplug it into the new computer-

If you used the 90 harness, and the 90 computer, you should be able to just switch computers, and replace yours with the A9L (reman is about $97 plus your core computer at a parts special store) but if you used the 87 harness, you prob didn't wire in a MAF and everythings messed up lol good luck - more info needed