(I searched on the forum for all those starting issues and diagnosis, I tried many things and didn't find my issue, so here it is)

So here's the deal..

So a week ago the truck started having misfiring issues, not really bad, and someday it began to be hard to start and it misfired a lot when cold.
So this week, the truck won't even start.

Code present:
- Multiple/random misfire code is present.

I have spark at the coil and at the spark plug. Although, the spark is orange, must admit, I used a screwdriver in the plug of and tested spark near an engine ground.

I have fuel pressure, however, I'm not sure if it's alright. When priming the pressure is 65, as soon as priming stop it drops directly and instantly to 55 and stay's there. I checked after 20 minutes and it was still at 55. While cranking, it seems to stay at about 50-55..

After a while, trying to start it, it began to smell like fuel. I checked the oil and it smells like fuel, but the consistency of the oil seems alright, it's not clear and sticks and is golden/brown in color.


So at first, I thought it could have been the cold and humidity in the distributor, but now, it sounds more like a fuel leak, although, I'm not sure if it's because it's now flooded due to multiple start attempts.

The battery is fully charged.

When I try to start it and as soon as I stop cranking, it sputters a little, 'dieseling' is the correct term I think?


Now I'm not sure what to do, it got spark and fuel and doesn't start.

 

P0300 is almost always caused by a fault in secondary ignition, (plugs, plug wires, distributor cap & rotor, & ignition coil). Low fuel pressure can also cause it, but your pressure and leakdown rate is fine. These engines are real fussy when it comes to ignition parts, especially distributor cap, rotor and plugs. They don't run well with aftermarket parts, use AC Delco only. This could be the cause of the orange, (weak) spark, it should be blue. Make sure to put a dab of silicone dielectric grease on each terminal, inside and out, of the cap.

The "dieseling" when the ignition is turned back, could be a problem with the ignition module or ignition switch. The ignition switch can be bypassed to determine if the ignition switch is the problem. It involves installing several jumper wires to fuel pump prime, ignition coil, ignition module etc. If you need specific instructions, just ask.

The fuel odor in the oil is most likely from cranking, (injectors are squirting fuel) and flooding the engine.

 

When you get it fixed i suggest changing the oil.

 

Ok I opened the distributor cap to see what's going on in there.

These are my observations, and I'll post pictures to the message.

- The rotor can turn about 1 or 2 degrees to take the backlash of the gear, is this normal?
- The contacts are brown in color and to me, they don't look that bad (pictures)
- The center contact on the cap is totally black

- I measured the resistance of the coil.
Input side (12 volts from the ignition module on the coil): 0.4 ohms on 2 pins, pins toward the front and center pin is 0.2 ohms, so looks like this coil is center tapped, to me this is ok, but it's quite a low resitance figure, almost shorted... normal ?

Output side of coil (HV side to distributor) I have 5 KILO ohms.. This is a bit high, but I'd understand that it's higher than input since this side contains a lot of winding. Normal?

The connector that connect to the input side of the coil, I measured the resitance to ground, it's about 1.5 ohms, this connector have 2 pins and is connected to ignition module.



Well, after doing these checks, I use sand paper to clean the contacts, I don't know if this is bad or anything, but I figured I had nothing to loose doing this, then I tried starting the truck with the pedal to the metal, so that air would clean up the cylinders and remove the excess of fuel (I think the truck is solidly flooded, strong smell of gas)

Well it didn't start, but sometimes it would fire up a bit for like 2 seconds then die..




**** Progress (or not progress)
Ok I removed one sparkplug, to my surprise, the sparkplug was finger tight, I removed it with my fingers! .. hmmm..

Then I retested the spark, it's now blue/white, seems good!
However, the sparkplug was very very very wet of fuel, so now I guess my problem is flooded engine.

So I tried starting it up a bunch of times (actually about 5 or 6 times; cranking for 5 seconds max) with floored gas pedal. And I think I finally killed the starter motor.. But I gave it 1 minute every time I tried starting to cool down...

Anyways, now when I turn the ignition to start, the radio light turns off and every lights in the panel turns off except Check engine light and belt light that stays lit up. It doesn't look like it's not getting enough battery power though.

My battery is charged at 100%.

Is that a shorted starter, solenoid starter problem or ignition switch not switching the starter?? .. I'm confused.

Looks like I should take a break before I destroy everything.

*** Btw, did I say that recently I had to change the master cylinder and alternator. I guess every parts are kind of flaky right now.

 

The brown contacts in the cap are burn marks. It was caused by not using silicone dielectric grease when the cap was replaced. Install a new AC Delco cap & rotor and put a dab of silicone dielectric grease on each terminal, inside and out, of the cap. Then check camshaft retard with a capable scan tool, and adjust it if necessary.

Slight movement of the rotor, to remove backlash, is normal. There should be no radial play in the shaft.

Spark plugs: AC Delco #41-993 with a gap of .060"
While the plugs are removed, unplug the fuel pump relay, throttle held wide open, crank the starter for ~15 seconds to unload the engine, (clear the flooding).

Plug wires: Autolite Professional Series #96871 (better specs & cheaper then AC Delco).

When the engine started & died.... did the red "Security" light illuminate on the dash?
Does it come on and go off with the bulb check?

Check all battery cable connections, make sure they are clean & tight. Charge the battery and fire it up.

 

The security light flashes when I open the door, I put the key in the lock it still flashes, I turn to on position it stops flashing and is not lit. I turn to crank and security light doesn't show up.

Thanks for the tips, I'll try that, as soon as I can crank it up! My starter is dead or the ignition switch is dead. There's a click when I try to crank but the starter doesn't turn. I might try the 'wack a starter' thing and see if it tries to turn. Is it really necessary to remove the engine mount to change the starter on the 2000 blazer ?

Also, you said, turn the starter for 15 seconds, well, the max I did was 5 seconds and it's now dead.. Maybe it was already on the edge of dieing tho, since I'm in a streak of failing parts. : Master cylinder, rear left brake flexible line, alternator, 4x4 electronics, distributor cap, rotor and now dead starter!

 

I have 96 which should be the same as your 2000 the starter should easy to remove with out undoing the motor mount.If you manuver it just right it will slide right out inbetween the Y pipe.

 

The security sytem is not causing the problem... just wanted to make sure

Ya know what they say.... "if it ain't one thing it's another" Keep us posted on how it turns out.

 

i am having a similar problem with my 2000 blazer 4.3 vortec, my intake gasket blew, so i replaced intake and head gaskets, no fire. so then replaced coil, still no fire, replaced ignition moduel and still no fire. now the plug that goes into the coil has to wires, i was told one should be constant hot with key turned, and the other will pulsate/flash with test light when turning suv over, i do not have the pulsating side, i have checked all my fuses and cant seem to find the problem, any ideas would be greatly appreciated, i have put alot of money into it this past year and would love to be able to enjoy it, thanks

 

Graigdavis, To avoid confusion, it would be best to start a new thread here:
https://blazerforum.com/forum/newthr...newthread&f=41

You can copy & paste what you have here, that's fine. Thanks.