Chevrolet Repair: Hard Start @ Cold, sitting or after run, fuel pressure gauge, chevy ck

Question
Mark,
    Have a 1995 Chevy CK 1500 1/2 ton- 2 wheel drive, 305 CI with a Manual, 103,000 miles & owned since new. Initially-- noticed this, which has progressivly worsened, kind of a flat acceleration spot @ 2300 RPM's and beyond. Also, if truck is left over night, or for a few hours--it has become hard to start, which has now gotten bad.  As well as, after driving the truck for 40 mins. tonight, I tried shutting off the engine and restarting right after -- just cranks. Let sit a few minutes then it may or may not fire up, if it does, idles rough--fluctuates between 300 & 900 rpms' until you hit the pedal--then it will smooth out and idle fine. Checked out Fuel Pump relay, pulled gas cap off - stuck ear at nozzle, had buddy turn key on--could not hear Fuel pump come on for 2 to 3 seconds. I Figured relay -ok, I replaced did not help--very faintly cound I now hear pump come on.---It So happens buddy has same truck, 1992 checked his -- I can hear is pump more--noiser. Pulled off air cleaner housing and lower plate so as I may see nozzles, had buddy crank engine over -- nozzles pulsing fuel, appears to be getting there. Truck has alway been maintaned by me, always preventive maintenance --I'm a wrencher !

 Also did nomimal checks, cap, rotor, plugs all fine, clean--Usually I change all that out at every 35K. Wires were replaced @ 75K, Fuel Filter at 50K.

Puzzled ? -- as I write this note, I stuck with my truck in the parking lot !

-- Please Help !

Answer
Hi Rich, The most common thing with type of problem is the fuel pump. Low pressure from the pump will only spray small amounts of fuel and this isn't enough to start the engine. The best thing is to install a fuel pressure gauge to see what the pressure is when it doesn't start.

       The only other part I have seen very few of is the coolant temp sensor. If it reads out of range...too hot, the fuel that is sprayed out will be very lean and not start the engine. You could try disconnecting this sensor which is by the thermostat housing and then try to start the engine. If it runs this could be your problem. If you had a scan tool you could look at the reading to see if it was bad.

Hope this helps you

Mark