I would like to say thanks to all of you who responded to my request for help' I think I may have found the problem. At least one of them. The low gas pressure was caused by a vacuum leak at the fuel pressure regulator. [ To Paul Workman & ZWILD1 ] you 2 got me going in the right direction. Thanks.
I am still not sure I have the 405 HP. I repaired the vacuum leak and went on a couple of test drives. I haven't driven this car much in the past 15 years or so I am not sure how it should feel at full power. It doesn't seem to have much power in the lower RPM range but pulls strong once up about 4000. There seems to be a big difference between C4 ZR1 & C6 Z06. I know the Z06 has more power and less weight but there is a Big difference. It might be because I have become accustomed to the Z06. How ever it does seem to run better than it did before I repaired the leak.
I have another question about the ZR1. A short while after buying the car new I took it in for service at the only dealer who had a factory trained mechanic for the ZR1 in my area. The mechanic doing some diagnostic checks replaced what I think was the PROM, He said the car came with the wrong one and replaced it. I still have the one he took out. It's about 3/4 inch by about 2 3/4 inches. Did any of you have that happen? Or do any of you know about a service bulletin back then that pertained to a ECM needing the PROM replaced. Is there some place I can go to read about Engine service bulletins for the C4 ZR1's. Just wondering why it needed to be replaced.
Thanks for your help.
