Problem w/ ECM. Rev Limiter?/ Throttle Cutting issue past 4k after 2nd gear.

[cactscool]

I have a 89' KA24e engine in my car w/ 5sp Manual transmission. The issue I'm having right now is this.

1st and 2nd gear are really strong. but as soon as I get to 3rd and I push it too hard.

My throttle cuts out. IT feels like a jolt in the car, then all of a sudden complete power loss and no throttle response until the rpms slowly drop to around 2k, Usually happens at WOT on freeway.

So this is how the throttle cuts out:

3rd gear @ 5krpm4th Gear @ 4krpm5th Gear @ 3.5krpm

it's starting to get annoying because I cant even push the car at all or it will do this.

Mechanic says that it's because my VSS (vehicle speed) is not giving a signal into the ECM. So that's why the computer is telling the engine to cut out at those RPMS.

Ok this makes sense, and i'll accept that . My question is though, how come my Speedometer and tach are still getting readings and (kinda) working still? I thought u need VSS to get any gauge readings on speed and RPM. Can a car function like that without VSS?

Also i'd like to note that my speedometer is kinda jumpy, and at higher speeds 40mph -80mph. it's waaay off. by like 20mph. If i'm going 40mph it will say i'm going 65mph. (probably why computer is confused)

MY MAIN QUESTION: is, how can I solve this, if the answer isnt obvious, Should I just get a stock 240 VSS and connect it in the transmission? Where do I get a VSS from? Also my guages are Autometer electronics, aftermarket.

anyone selling a VSS for a 89 240?