Sorry to hear that the Blazer has seized up, but in reading your posts of terrible gas mileage, I'm surprised no one mentioned that you could have a faulty/failed/ruptured Fuel pressure regulator. Take a peek into the upper intake plenum (through the throttle body hole, with a mini-maglite you can see if one side is clean and the other side is sludged up, then the FPR is leaking. Replacing the fpr usually restores the fuel mileage to a better number than 7 mpg. The Blazer, while not a stellar performer in the mpg range, 18 to 21 mpg's should not be unrealistic. I'm getting just shy of 20 mpg's out of my '96.

 

well it's a bit more than I had expected but I found another 4.3 vortec with only 67,000 miles it $900 still a bit cheaper and faster than a fresh rebuild tho (plan to rebuild mine and swap em out when its finished and a little warmer outside). Will keep you all posted on progress.

Ryck

 

Before you go dropping coin on that engine....

Do you smell gas in the oil?
Hows your oil level, too full?
If your FPR is dumping fuel it will stop your engine from cranking over. Liquids dont compress. Took me almost a week to figure that out. Teh parts store had the wrong FPR in the box. The box was correct, it just ahd the wrong part in it. It was dumping gas big time and locked my engine up. I could spin it by hand, after the gas drained into the oil pan.

A new FPR is like $70.

 

Thanks alot yes the oil does smell a bit like gas and yes it was a little over full will try this first (worst case i put the new fpr on the engine I have to buy if it doesnt fix this one) won't have time til this weekend but will let ya know how it works out, thanks again for the heads up much appreciated.

 

Now that the engine has sat for some time, go see if you can crank it over by hand on the crank bolt agian. If you still have too much resistence, take all the spark plug out and try again. If oyu get gas out of hte spark plug hole at least you know your rings are sealling great,a nd the better news is your gas is ending up in the chamber. Could be leaking spider assembly too, although you will be able to tell once you take the upp intake plenum off.

Another test, leave teh spark plugs out ans see if it will crank over by the starter, remember to pull the coil to distributor cap wire. If the engine cranks, you knwo its not locked up.

Simple tests that cost nothing other then time.

 

well I decided to skip class tonight and go screw with my truck instead (of course I didnt even get off work til 30 mins after class started and its a 1 hour drive from work to there so made my choice easy lol) drained the oil out, pulled the plugs and it turned normally by hand so I then proceeded to pull the upper plenum off and lo and behold a one inch deep pool of fuel on the passenger side (of course part stores closed now my luck is great) so soon as I get off work tomorrow its getting a new FPR, new plugs (again), fresh oil change and should be golden (I hope) thanks again for the help saved me a ton of cash I didnt really have to sink into my truck atm and I really appreciate it.

Ryck

 

I cannot say it enough thank you all for your help, got my truck all back together today and it's running better than it has as long as i've owned it, every problem in my initial post is gone and a 30 mile trip yielded gas usage of 1/8 of a tank vs the 1/2 tank it was using before.
again thank you all!