I have a 2000 Blazer LT 4x4 with 105K on it. As of lately I have had a starting problem and it has only gotten worse in the last couple of days.

For openers, I brought a 2011 LTZ Nox and the 2000 Blazer had to leave the protection of the garage and I think its been mad at me every since.

I have done all of the checks except the fuel bleed down and pressure check, but I don't think thats the problem, could be, but, I'm leaning away from it, why? The engine gets flooded while trying to start it.

I had replace the plugs about 5K ago and instead of the standard 32 plug, I put the 33 plugs in and that appears when the problems really got worse. I pull the number 1 plug out, the one that can be reach easyly from the top and the plugs were pretty wet with fuel. So I stuck one of the old plugs in there, let it sit for a day and no start at all, so I pull the same plug and it was as dry as a bone. So I squirted some cab cleaner down the throttle body and it started right up. It miss a little at first and had a small back fire then ran fine, took it out for a spin and it ran fine. Came back home turn it off, started it back up, it started fine. Let it sit for about 4 hrs and decieded to make a run to the gas station and put a few gallons of fresh fuel in the tank (The fuel in the tank was about 4-5 months old), Went out to start it, and it gave me a small problem in starting but did and it miss a little then ran fine. I plan on putting the old plugs back in today (They only have 50k on them) and see what happens.

Is there any other suggestions out there? Like I said fuel doesn't dosen't appear to be the issue since it flooded the plugs were soak with fuel. I also replace the cap and roter when I did the plugs. Could it be a firing problem, I'm only one person so I can't check the color of the spark while cranking it. My plug wires are orginal and when I wait for darkiness, I lift the hood take out the bulb and start it up and I see no arking at all any where. Oh, and I only use AC/DELCO parts and the motor is pure stock.

Thanks
Dennis

 

Also would like to add that I check the fuse and relay, (Swap out the relay with the horn relay) and everything was fine there. When I turn the key on I can hear the fuel pump kick in and turn the key off I hear it kick off.

 

Is your tach needle bouncing when you crank?
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Sorry...There really is no substitute for that pressure leakdown test on this system.

And the plugs being wet is not an absolute indication, either, if the mixture isnt rich enough to fire but still carries gas then it still could show wet.

It would help if folks still used the old 'hard starting' drill from carburetor days.. it still works, at least in our cars.

If you think it's flooding, hold pedal to floor right after you start to crank engine.

- When the PCM sees you did this it will cut down the injector cycle, delivering less fuel

If you think it's not getting enough, pump the pedal several times while cranking

- When the PCM sees this it will inject extra gas.

https://blazerforum.com/forum/genera...t-start-64918/

If one of those... or neither.. worked, it would be a good clue.

 

You are correct, I do need to pressure test it with gages. I did replace the 93 plugs with the 92 plugs (What the book calls for) and after sitting for a day. I started it, it took a little coaching (The old carb method, thats what I was using before with the 93 plugs, until it wouldn't start anymore) I even did the foot to the floor, nothing, thats why I change the plugs back. I found it best to push the gas pedal 1/2 way to the floor and it started, it clug a little but started. The engine appears to run better with the stock plugs in it, smoother idle then with the 93 plugs, the 93 plugs it was a little rough of an idle, the tack would bounce around a little with the stock plugs it was steady. I haven't paid any attention to the tack while trying to start, I will do that today. What am I looking for in the tach?
Thanks for the info.

 

For the tach, all you're looking for is that the needle bounces off the peg a little while you are cranking. This means the pickup and ign module are working.
- The tach signal passes through the PCM, no idea whether straight through or relayed, but since the PCM fires the spark, anyway.. doesnt matter. Means the ign circuit works somewhat.

I have no idea why our trucks {or is it Vortec engines} are so sensitive to ignition quirks...except that the engine compression ratio is 9.3:1. And then there's the injection system.
- IMO, this all started with HEI. I only had one car with it. And only one prob, the coil. But it seemed like everyone else did.

Whatever ..it cant hurt to review the whole high voltage side. Start with being sure you have a good cap and rotor. That the rotor mounting end of the dist shaft has no side-side slop and very little rotational slop.
Then the wires:
Start with the Blazin' After Dark test. Raise hood in the dark look for micro- lightning, spark jumping, around the coil and through the wiring runs.
Bravadiva threw a 304.. I moved the wires around. Code went away.. But I could see a faint brown area on the wires where it was happening.

 

Thanks will do, I check the for spark leaks awhile back, I will check again. I replace the cap and rotor appox 5K ago. That should be good to go, but will check again. (Same time I replace the plugs) I haven't tried to start it for a day now, (Football day) will try today...What type of voltage should I be looking for from the coil?
Thanks

 

Well, Did the start thing Monday and it started up with only a little coaching. I 1st turn the key on and heard the fuel pump kick in and waited about 10 seconds with the key on, then turn it off waited about 5 seconds put the gas pedal about 1/2 way down and after maybe two, three tries at it she started right up, thats a big improvement from beore when I would crank and crank and push the gas pedal all the way to the floor, etc. The old carb method of starting. I think just maybe outside of the hotter plugs that were in it and bad gas just might have been my problem. Time will tell...still need to put some gages on the fuel system for a test...
Thanks for all the help, this site is amazing, maybe thats why I have been a member since 2007...Its just chock full of possible solutions..

Thanks again