starts fine in the morning. sits and idles a few min. then loads up dies. sometimes runs longer sometimes doesnt die. has hessitation sometimes coughs and chokes. when accellerating.if ease off pedal comes back alive. sometimes check engine light goes on for a min then off. assuming because o2 sensor reading lean or rich exhaust. have replaced plugs. check cap and rotor. replaced temp sensor, and fuel filter,egr valve. its a 95 chevy s10 4.3 tbi
The problem might be with the fuel injection system.
Your vehicle has the Central Port Fuel Injection system. This means there’s a central fuel injector located under the intake manifold that supplies fuel to the cylinders via plastic hoses to what are called poppet valves. This whole arrangement is called the SPIDER assembly.
This system can have problems with the poppet valves. As these are a ball and spring arrangement where the fuel pressure is what blows these poppet valve open to intoduce fuel into the cylinder. These poppet valves can become stuck from gum and varnish where they begin to stick and fuel control into the cylinders is lost and the engine doesn’t run well at all.
You can try adding a fuel system cleaner and see if it free’s up the poppet valves. If that doesn’t work, I see a spider assembly in your future.
And I forgot to add. Check the fuel pressure. It should be over 60 PSI.
Tester
I wonder what leads the op to believe the vehicle is tbi equipped? he did include this information in his description (95 Chevy s10 4.3 tbi)
My 95 FSM does list a VIN “Z” engine available that is TBI. VIN “W” engines are central port
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This is what happens when manufacturers don’t want to pay licensing fees to Bosch for decent fuel injection technology…Some of the “interim” systems worked and some didn’t. Honda stuck with impossible to repair feedback carburetors until it almost put them out of the car business…Ford used a C.V. feedback carb on it’s Merc’s and Lincolns which sent many good dealership mechanics into early retirement…That was a rough ten years…
I CHANGED THE (TBI) unit also
Have you cleaned the idle air control valve, throttle bore and plate, with Throttle Body Cleaner? And, what is the fuel pressure when you put a load on the engine, or at idle?
So you did know what type F.I. your truck used and it was a CarTalk member that “jumped the gun” by telling you to repair your central port fuel injection,understood, I apologize for the erronerous information you were presented.
No check engine light?
the problem could be a simple as a gas cap that isn’t properly venting. cap doesn’t vent, vacuum is created in tank, fuel can’t travel to injectors.
try taking the gas cap off and starting the truck. if it starts and runs OK, there is your problem. remember, the simplest things first before you start swapping parts out