Ok so my car seems down on power.

I just got it put back together and it has the same, I just rev without making power above 4500 or so. I had figured it was the opti, but a new one is in place and the same thing. Tired valve springs, well replaced those too, stamped steel rockers well those are roller now. When I 1st put my car back together 2 years and 5k miles ago it ran very, very well. I added exhaust and that seemed to choke it a little but not that bad. Then I added ZR1’s and nittos and the car could only manage 102 traps down from 106-107 with full exhaust in the same air???. But it had been losing steam before that. I changed the wires and plugs 106’s to 104’s added an Acell 300+ and still no resolve. Hence why I tore it back apart and changed some stuff to no avail. Did a compression check: looked better then I would expect from a 120k short block. I mean the car would spin new GSC’s from a roll, through 2nd (auto). Now I can’t get a squeak out of cold nittos. I know my converter is stock, but I don’t feel that is the whole problem.

Set up
Stock heads, 218/224ex, stock tb, 1.52 pro mags, csr pump and double roller, cai, Edelbrock shorties, cat co 3 inch cat (less then 500 miles), flow master single 3 in and out, 3.42’s out back and a Madz28 tune. Have two chips one for emissions and for not. ( been running the emissions tune)

I am running 24lb injectors, a newer regulator and adjustable hat, and a stock fuel pump w/ about 50k and 5 years on it with a new fuel filter. But all of this has been sitting for a while. The car seemed to run better with lots of fuel pressure 53 psi or so, but then idle quality was bad at best. I am suspecting a lazy fuel pump, but haven’t been able to get to a dyno or a long enough gauge to see in car while driving. What should the dip be in pressure at WOT, its set at 43 now.

Sorry for the length, but I had nothing better to do at work

 

Do you have the stock cat still on the car?

I would guess clogged cat or else check the compression ratio.

 

Nope its a Catco and its new, also checked the compression within 5%

 

There should be NO dip at WOT.
It likes fuel pressure probably because the injectors are to small to make the HP it is capable of.

Get a tune and that will solve your FP issues at idle and ya can set the pulse width for upper RPM'S and probably drop the FP.