97 blazer, 4.3L V6 with about 150k on it.

Car just died the other day. Has a full tank and turns over, but doesn't even sputter when cranking. Distributor is turning, has a spark, but weak orange color. I replaced the ignition module, and crank position sensor. Replaced the fuel pressure regulator about 5 months ago. Connected a fuel pressure gage to the rail, and I have 52-54 .lbs when the pump kicks on. I scanned the computer, no codes at all.

I'm stuck, don't want to replace more parts until I know the problem...any ideas?

Thanks Steve

 

Is the injector engaging and spitting fuel?

 

Can't tell for sure. This engine has the 2-piece intake aluminum lower and plastic upper. Last year I removed both intakes to repair a leaking gasket. I had cleaned the poppet valves in the lower half, and replaced the fuel pressure regulator. It ran for a long time before this problem. Before the engine died, it had a little sputter on the highway that was intermittant.

Is there a was to trouble shoot the injectors if the engine will not start?

 

Have you tried putting fuel in the throttle body manually?

 

I suppose I could spray starting fluid into the throttle body while cranking it over. I'll let you know how I make out. Thanks for the suggestion

 

With a weak orange spark, it doesn't matter how much fuel you have. You need to get hot, blue spark.

I'd check the coil, personally.

 

my little 2001 blazer is having a very similar prob-new battery but wont start unless fuel poured in throttle body-thinking its fuel pump,fpr,or just gummed up injectors-i hope ypu get er fixed and back on the road!!

 

52psi seems a bit low. 55+ is what these engines require from my experience and GM says 60 at a minimum. How is the leak down rate after the pump shuts off?

 

would a 3-5psi below normal pressure cause the engine to not even start?

I'll try the starter fluid trick, and check the coil. I can check the pressure leak down when the pump turns off too.

could it be another sensor or the computer giving me troubles?

 

Yes, 3-5psi could cause it to not start. GM states the pressure should exceed 60psi, but I have seen some engines start as low as 55psi and not start at 54psi. The reason lies in the design of the fuel system. In the initial SCFI spider, the electronic injectors are housed in the main spider body and feed pressure actuated poppet nozzles. Think of the poppet nozzles as relief valves. They'll only open when the fuel pressure overcomes the spring pressure in the nozzle. If the pressure is too low, they will not open.