I noticed a few days ago that my truck seemed to bog down when it would shift gears. Then yesterday it won't start. It just cranks and cranks. I changed out the fuel filter but it still won't start. I also checked for spark in one cylinder and it does spark.

It's the 6cyl TBI.

Any help will be appreciated.

Thanks.

 

My '94 Is doing the same thing!! I know I am getting fuel, not sure about spark yet. I recently replaced the fuel pump, fuel filter, spark plugs, and air filter. My assumption is that I may have a weak coil pack. Let me know what you come with, seeming as I still have a truck that wont start!

 

Not sure if you fixed the problem but i just bought a 94' s10 pickup and it had a bad fuel pump which made it only crank over and over, when i was replacing the fuel pump i decided to make sure it wasn't the fuel pump relay so i disconnected the fuel lines from the top of the fuel tank so i could see if it was pumping fuel, i then replaced the lines and tried starting it, it ran very rough and sputtering just like most on here have doing, so i replaced the pump and it fired up perfectly, now i just need to resolve my overheating problem, good luck.

 

I have a 94 blazer as well. Mine runs but with issues that I am constantly working on. My grandfather was a mechanic his entire life and tought me one thing from the get. Spark, Compression, Fuel, that is a little check list. A common problem on the 4.3 is the 2 fuel lines inside the upper plenum they crack and cause idle issues at first then issues through the entire rpm range. To see if they are ok the you need to take the upper plenum off and if the right side of the lower plenum is clean that is it. If your left side is clean then it is the fuel regulator. Also if you turn the key to the on positon then you can look to see if anything is leaking. I would check this out first as this seems to be the issue with those motors and the only issue. They run forever as long as you give them fuel.

 

I replaced the fuel pump and sending unit that had a burnt wire. I was then getting fuel to the fuel regulator but it was leaking. Replaced it and still won't start. I can use starting fluid and it will start and then die. Any idea what now?

 

Either bad injectors or they are not getting the signal to turn on.

 

I just had this issue this past weekend and a new fuel pumped resolved my issues. While at the parts shop an employee did mention having a bad injector, this could be your issue if you have a good fuel pump.