97 K1500 engine problems

Hi, my gmc k1500 with 350 vortec has been having problems starting and idleing rough.

i have to press the gas pedal a little to get it to start, then when i idles runs rough. i have a po300 code(random missfire). i have changed plugs, ran 5 tanks with gm fuel injector cleaner, nothing.

over the past year have had the Distributor and wires changed, changed 1 o2 sensor, new catalytic system, and one set of new injectors.

I have spent alot(afraid to add it all up) prob 3500 dollars and nothing has worked so far.

Any help would be appreciated.

Welcome to AF, leaking injector assemblys and fuel pumps are the most common causes of these symptoms, get the fuel pressure checked, you need 65 psi and it should bleed down slowly when shut off.

Thanks for the quick reply, forgot to post a couple of things.

They only changed one side injectors

The truck seems to run fine when not idleing (normal driving) doesn't miss.

I will have the fuel pressure checked.

Thank you.