Ok group an update on this thread,i still haven't got this engine or trans to run or shift like it should.Everything Ive read tells me to do a engine relearn.Ive read that the engine will run as it did before if it was running bad before a swap and also the trans is shifting correctly and that a relean is neccesary to restore the shift points back in the trans.Can somebody confirm this?

 

My 2 cents

If you have a felt misfire but no SES light, then the misfire detection system is not working. You may have some luck working that angle, and that may (or may not) have something to do with the crank sensor. However, please be advised that lack of a crank sensor relearn should not cause a misfire, and shift points are part of the PCM programming that doesn't change. If you have a felt misfire and malfunctioning misfire detection, I really doubt if anyone will be able to get a crankshaft relearn to actually trigger. Seems there are a lot of prerequisites to be met in order for the procedure to begin and you would probably be subjecting your engine to 4500+ RPM repeatedly + shop time with no result. If you have never had a crank relearn done since switching the engine, that will definitely need to be done for the misfire detection to work correctly. If you disturb or change the crank sensor at this point, you will need to do the crank relearn again. So first I think you will need to get rid of the miss and verify all is OK with the system before worrying about that kind of stuff.

For a cylinder to fire it needs the correct amount of fuel/air, adequate compression, and a good spark at the right time. There are your basics. Electrical problems are far more common than fuel problems. If anyone still had oscilloscopes in shops it would be much easier to diagnose ignition problems on these Blazers.

I would start by checking for spark through each plug wire and the coil wire with an inductive tester. This can be very revealing if spark is missing or not steady. I used to have a really cheap one that looked like a pen and you just laid the end on the plug wire and a bulb in a window would glow when the electricity went through the plug wire. Same thing as a timing light would do when clamped around a wire. Here is such a tester. Note that steady spark through the coil wire implies the crank sensor is working fine, as well as the primary side of the ignition and the coil itself.

http://www.denlorstools.com/home/dt1...re_tester.html

If nothing apparent I would checking spark plug routing. You might have switched a couple. Cylinder number should be labeled on the cap. Inspect both terminals inside the boots on each end of each wire for corrosion (shine a pen light in there). Inspect the length of the plug wire for damage of any kind. Check resistance of each plug wire with an ohm meter. All should be well under 10K ohms.

Remove the distributor cap and rotor and inspect carefully for corrosion, cracks in plastic, carbon tracking, etc.

Pull the spark plugs and keep them in order. Inspect the porcelain for cracks and color, both ends of the spark plug. Note the gaps and any that look different from the rest. Take the steering column loose from the box if you can't get that #3 plug out without breaking it. This plug would be particularly suspect for prior damage.

Check compression (with all spark plugs out and a fully charged battery). Write down the numbers for each cylinder. You should be at least 110psi or so on each. Cylinders have a hard time firing below 60psi.

If that doesn't reveal your problem, come back and we can continue with the fuel system. You will need a scanner that can live monitor your O2 sensor readings.

 

I know its been a while but thanks for replying with the info you shared.
Let me start back with that I used all ac delco parts on the ignition system cap,rotor,plugs and wires.
Checked all the boots make sure the metal connectors are snapped good and tight on the ends of the spark plugs.
Fresh gas and starts as soon as I hit the key.Like the engine doesn't even make 1 revolution before it starts.For the most part it fairly smooth but not perfect as a brand new engine should.
The spark is strong for the coil to the distributor,I will check the spark from the each point on the distrib to each sparkplug as I haven't done that.
I do know that the engine is running very rich,the smell or odor of exhaust fumes is very strong.I also have a vacuum leak somewhere and I think its one of the lines going to 3 hole connection that goes to rear transfer case.I have plans on checking those things just haven't had time yet.Stay tuned I will report back with my findings