I rebuilt the engine for an 88 iroc and it worked great for a while. But one day (or it seems like) I lost a lot of horsepower and it started ticking. I fixed an exhaust leak and put in all new bosch plugs and it ran good but it wasnt giving as much hp as it should have been. Then I decided to change the wires to hopefully resolve the issue. After installing the wires, it ran worse than it did before I changed the plugs. So I tried a new set of wires, again. Didnt work. Tried the old wires. Didnt work. So I then changed the distributer cap and ignition coil and checked the timing. Still didnt work. The car runs ok until about 2000 rpm, then it cuts out. If I am running over 2000 rpm and i try to accelerate, the rpm will go down, then back to where they started and SLOWLY get higher. I have tried checking error codes (which is VERY rarely on), but the only errors I get are mass air flow sensor and speed sensor. I have replaced the mass air and due to its price, I dont want to again if there is nothing wrong with it. Occasionally the car sounds like its missing, but the timing is right. Any advice? Any will be appreciated. I dont really trust taking it to mechanics anymore, so I want to avoid that if possible. Thanks.

 

WAG you got the wires, or two wires on wrong. seems logical since it ran worse after you "fixed" it.