Hello all and thanks for taking a look. 89 5.7 stock. new injectors 22lbs (aouthbay), new distubutor with GM module, new MAF, new TPS, new declo plugs, wires cap and rotor. Cat is not the issuse since someone helped it out, if you know what I mean.
this car is a SLUG off the line (2.77 gears) and almost dies when I punch it, if I start off easy it will go but no pull really. If I was in a 1/4 I bet 17 might be tough since off the line is sad.
Had fuel pressure checked today -
20 psi key on engine off (spec is said to be 45psi?)
36 psi engine running (spec is said to be 45 - 48?)
Is this a fuel pump issue, regulator or something else?
I just want this car running correctly and have been dumping in $ since I bought it. Truly getting way better but not where stock should be yet.

 

key on would prime the pump, which would run a few seconds and turn off. This fills the rails with fuel and builds initial pressure but when the pump turns off, fuel can drain back and lower pressure.

Engine running has the pump running all the time so its able to maintain best pressure. I always check my fuel pressures with engine running.

I no longer have TPI or TPI style regulator but my external regulator will prime to 30-40psi and quickly fall down to 20's or so but when running it stays up at 48psi where I set it.

Sounds like you need more fuel pressure to get up to spec of about 43-44psi

 

36 running is totally normal. Pressure is regulated down 1:1 with manifold vacuum so idling around 35-ish is normal. Unplug the vacuum line on the FP regulator and you should see 43.

 

Thank you for the replys. Okay, so I am good on fuel pressure, I just don't know what else it can be..... timing set incorrectly? I had someone else put in the injectors and while they were at it I brought up the dist and module. It want to sputter if I floor it from a stop, if I go in EASY, then it will go but never put you back n the seat. I have driven other camaros, vettes and I know that the 5.7 will give you the torque feel but this car still does not have it.
I bought it from someone that said they inherited the car so they knew no specifics. The cat has been hollowed so I know someone was trying to get HP. Now the question is: what is the correct timing if they made some other changes? It could possibly have a mild cam - It does drive fine and idel fine just never seems to Downshift like I want on the highway or power form a dead stop.
Suggestions? O2 sensor, knock sensor? Money isn't the issue it is finding what is wrong because three shops all who after talking with them talked the talk about knowing what to do but they all get closer without walking the walk.

 

O2 isn't in play at WOT. Knock sensor maybe, but I wouldn't jump to conclusions on that.

How are you checking the timing? Are you disconnecting the timing wire before you set the base timing? If not, it's way retarded. Set properly, the factory spec is 6* for base timing with most finding that an extra 4* above that (10*) gives some more torque without causing any other real problems.

 

Try changing the fuel filter....Key on engine off 36/38 psi...Engine running at idle 38/42 psi...engine off after running 40 psi and about a 1/2 hour to retun to zero pressure.

Fuel pressure on my car is set @ 45 psi (adjustable FP regulator) and above pressures are noted from my underhood FP gage.

 

Timing was the issue. I took it back to the shop twice and they said "it's right" without checking it out. So I called a buddy with a timing light since I did not want to break down and buy one just for this. The timing was way out - the mark on balancer was over 2" away from the tab. We set it at 6 degrees. I didn't want to go any further since I am trying to keep it totally stock.

THANK YOU GUYS FOR ALL THE HELP!!! I don't see a lot of threads with follow-up.

 

fuel pressure is checked with car running and vacuum hose disconnected. Stock should be 43.5 psi