Lost top end power

[bobtodd]

I bought my 91 LX about 5 months ago. When I first got the car it would scream. The powerband would kick in around 3000 rpms and pull hard until I would shift around 6000 rpms with no signs of letting up. You could even get the tires to break loose at the top of second. Well, over the last few months my car has lost that power and I'm not sure why. I can feel the powerband kick in at 3000, but it only pulls until around 4500 rpms and you can just feel that the power isnt there like it was. Everything on the car was put together by the guy I bought it from...bored .30 over, balanced stock crank, 10.5:1 KB pistons, ported 289 heads with 2.02, 1.60 valves, 588 Ultradyne cam, cobra upper and lower, long tube headers, etc. I thought maybe I was just getting use to the car, but I emailed the guy I bought it from and he said the car use to pull hard up to 7,000 rpms when he had it. I'm just wondering if anyone has any ideas on what could cause a power loss up top like that. I did have the car dynoed and the sheet shows power dropping off very rapidly after 5,000 rpms. I am going to check my timing tomorrow and get a fuel pressure gauge so I can check that. If anyone has any ideas please let me know. Thank you.