[costomchevy]

Recently put in a rebuilt 350 (55-79 block) that's been bored .060 over. I put the heads and FI on it but it runs really bad at low rpms have changed plugs wires cap rotor tps maps but still won't run right

[CaptainRich]

When you installed the fuel infection system (FI), how did you select the system that you are using?
With any computer controlled engine operation, the on-engine sensors and senders need to provide the appropriate info and make appropriate adjustments with actuators and switches.
Is what you've installed capable of doing that efficiantly?

[costomchevy]

Its all stock 88 sensors and tbi

[costomchevy]

Runs good at idle but between 1000 and 2000 rpm it sounds like a camed motor

[CaptainRich]

I'm not sure what you mean when you say, "camed" motor.
Is it misfiring? Does it set any DTCs?
Other than boring oversized, what else has been done to the engine?

[costomchevy]

Doesn't set any dtcs don't know what alls been done to the motor I bought it the way it is
Was thinking about putting the cam out of the old motor in it in case they put a performance cam in it
Other wise I'm baffold

[CaptainRich]

Running poorly at idle could be several different things, from wrong ignition base timing to incorrect fuel delivery. Some things you can eliminate easily. Others may require experimenting.
If I was working on it, I'd go back over the basics and see where it leads from there.
After it's been running poorly, what do you have to do to smooth it out? If just increasing engine RPM above idle is enough, you may be getting a poor signal from the TPS that isn't enough to set a DTC but enough to alter fuel profile at that RPM.
Let us know what you find.

[costomchevy]

It runs great at idle and it will run OK if the timing is about 15* out (couter clock wise) and I've triple checked every thing has new plugs wires cap rotor and all the sensors have been changed for ones known good new coil ecm icm double checked firing order new timing chain
Did notice that when it starts running bad the fuel a spraying right what is fuel pressure supposed to be

[CaptainRich]

Ignition ON Engine OFF: 62-90 kPa (9-13 psi)

You can shine a timing light on the fuel spray to see if the pattern changes any when it's running poorly. It should have a good spray pattern and it shouldn't change shape when revved up.

[costomchevy]

That check out good needed a filter made it run better but still can't time it were its suppose to be when the line on the balancer is a couple degree to left of the last mark on the timing bracket