Seems like my 4.3l Blazer with 164000 miles (still runs like new!) is having a fuel related hard starting issue. It has been getting progressively worse to the point where it now happens everytime the truck sits overnite. Basically, you crank it excessively and the engine will sputter once or twice, like it is going to start. Eventually, you get it started or kill the battery. I can start the engine immediately by spraying starter fluid into the throttle body.

I hooked up a fuel gauge to see what is going on. By turning the key on, I get 59 lbs of pressure. If I shut the power off, after 10 minutes, the presssure may drop 1-2 lbs at most. When running, the fuel pressure runs around 52 lbs. If I pinch the plastic fuel return line (next to the fuel filter), the fuel pressure doesnt seem to rise. If I shut it off and come back after 10 minutes, the presssure will rise to around 62 lbs.

The fuel pump was replaced 5 years and 55000 miles ago. The fuel filter is brand new. I never replaced the spider or fuel regulator.

Any ideas? I'm not sure if it's the fuel regulator or fuel pump?

 

Sounds like the pressure is proper. The problem could be sticking poppet nozzles. Have you tried running a double 20gal treatment of Chevron Techron Fuel System Treatment Plus?

 

If you mean dumping 2 bottles of it at once, no, I haven't. I used one bottle into a half tank full, but didnt do much. Maybe I should try it with 2 bottles.

Sticking poppets sounds like a good suggestion; it was worse when the temps were below freezing. I also would get a "soft" P0171 code. The MIL lite would come on, but would go off by itself too, after driving a while.

Thanks for your help so far.

 

The symptoms sure fit for sticking poppets. That would definitely get worse the colder the engine was. If a double dose of cleaner doesn't do the trick, you are only out a few bucks. A professional injection cleaning will run you $60-$100 and still may not clean up the poppets. For $250-$300, you can buy the updated MFI spider and install that which will get rid of the problem for good.

 

Thanks, swartlkk. I'll try it and report back soon. Might not be for a month or so, I'm driving a different car at the moment.