I recently did a tune up on my 91 si hatch thats bone stock, including fuel filter, wires, plugs, rotor button and distributor cap. It idles fine but then the check engine light comes on, with the ECU flashing 4 times. I tried flooring it in neutral, it can't get passed 3k rpms, and accellerates real nasty. I really need some help with this, i have to have my car running tonight. Any help would be great

 

4 flashes on the ECu is a crank position sensor error. My guess is that during the tune up you knocked this senosr off. Check for loose wires and plugs that are not connected tight.

 

Thanks but i don't think thats it, i can't even get the clips apart, the connection there is probably ok

 

The crank position sensor can throw eronious errors. Have you taken out the ECU fuse under the hood and left it out for a minute so the ECU will reset and then checked to see if the car runns better?

 

yeah just tried that, didn't work. I noticed that the car idles bad until the check engine light comes on, the it idles better but still won't pass 3k