Bought this 98 blazer with a bad valve for 500 bucks, alreadt had a set of heads to go on it so it was a good for me, it was my Daughters first car she paid for it and she helped me fix it, could have easily been done in a weekend but schedules that never worked out caused the job to drag out for about 5 weeks. I gave the intro because "Time" is the only explanation i can come up with for what happened.
On the re-assembley, i double and tripple checked everything as i went just so i wouldnt look like goof in front of my kid when i forget something stupid....(not that i ever would...), finally when ready to start i expect it to go like any other intake or head gasket job ive done (Done many...) and it starts but is just barely sputtering and cant even get to 3000 rpm while holding the pedal on the floor. I figured i must have dropped the distributor in wrong but i had set it to the marks and marked it with a paint pen when i pulled it out, i checked anyway and it was good, so i got crazy and started pulling plug wires with the engine running and only 2 cylinders would make any difference but every terminal was jumping a nice spark to the plug wire so i moved onto fuel, figure maybe i jacked up the injector harness during the job, all 6 had power, all 6 were getting a pulse, so i hooked up a fuel pressure gage and primed the pump and then made a jumper from battery to one injector pin and then used my test light for ground to the other injector pin and repeated for all 6 injectors, i could only get the 2 injectors on the contributing cylinders to cause a fuel pressure drop, so i pulled the upper plenum to have a look at the poppets. What i ended up trying first worked and i was surprized because it seemed too good to be true, i hooked the fuel line back up to the spider and repeated my previous test, without the upper plenum, while watching each poppet for fuel spray, i then used a small flat blade screw driver to depress the ball in the poppets that werent working and one by one after i pushed the ball in i could get fuel to spray by manually applying power. Note: it takes a lot of force to move that ball! After i got them all to spray a couple times i stuck the upper plenum back on and turned the key, the thing purrs like a kitten, revs great, idles smooth and runs great down the road.
This makes me wonder how many injectors and spider assembleys have been thrown away when they could have just had a slightly stuck ball in the poppet?

Anyway, my only conclusion was that sitting there for a number of weeks caused the fuel to dry up on both sides of the poppets and they were just stuck? I drove this thing home 85 miles when i bought it and other than a dead mis at idle and lacking power at highway speeds, you couldnt tell anything was wrong!

This was definitely a wierd one for me so i thought i would share in case anyone ever runs into this problem in the future, if i didnt have the tools and diagnostic skills that i do, i would probably be here looking for answers! So i hope this helps someone out.
Happy Wrenching!!

 

All I can say is "Job Well Done!"

 

Nice job! 95 and older CMFI poppets each fire 6 times for each two crankshaft revolutions, so they don't have a chance to get varnished up. 96 through 2002 CSFI, the poppets only fire once per two crankshaft revolutions so they tend to varnish up. That's the reason for the TSB involving the injector upgrade for 1996 through 2002, which totally eliminates the poppets. Poppets rely on fuel pressure to open them, the injector nozzles are opened by a solenoid... much more reliable, dependable, and accurate.