I have a 97 t/a, with a GM hotcam, hooker long tubes and all the bolt on's. This past summer my car started running a really rough and seemed to have lost the power it used to make so had it tuned by Jeff Creech. it had turned out that the fuel mixture had leaned out to a dangerous level (16.0 to 1 maybe) so Jeff got it fattened up and dyno'ed it, it only made 149 hp! so i ran a leak down test and found one cylinder with no compression ( burned valves ) so i replace the motor with a engine with only 30,000 and just got it running and to find out it still got the same amount of hp! this seems to have every one i know stumped, please can someone help me!!!!!

 

Seems like quite a fluke to get two motors with the same problems. Did you leak down the second one? Sounds like a good excuse to build a motor to me.

 

Wow, that's really weird. Get another car or something. I have no idea what to tell you. If you have put a lot of money into that car and feel like you can't sell it for anything, take it to a good mechanic and have him figure it out.

 

is it the same computer? sensors? it has to be there some where, fuel filter pluged, bad fuel pump? crushed fuel line, pump prescreen. bad gas, pluged fuel injectors. check leak down and compression on new engine, might be blown already.

any other info?

 

Expanding on that comment, perhaps you have a problem elsewhere that is causing these cylinders to go bad.

 

maybe firing on 6-7 cyli,der/

 

Are you sure that your timing gears are setup correctly from when you did the cam install? Did your new motor come with a new opti or coil?

 

no i have not ran a compression check on the 2nd engine, well and another thing when i had it tuned and we seen it was running very lean the first thing we done was to check the fuel pressure and it was right at 42 or so ilbs, and then Jeff put in a obd1 computer to tune it, to find out it made 149 hp. right before (3 months) it started running lean i had to rebuild the optispark, today i checked the waveform of the high and low resolution signal thinking it might not be advancing the timing right but it checked out ok, i think i have a open circuit on the ect sensor becuase it reads -40 f do you guys think that may be the cause? thank you for all your respones and help!

 

was the fuel pressure checked with engine off, idle, and under load?

and the bad ect sensor signal can make a differance, I had one go out in my car, and it ran like crap, dying at idle, or idleing low, 400 rpm's. swapped it out, new one was like $8 and fixed it, so see what you can get done with that signal.