If it was the ignition switch, would I still get this problem when I remote start it ? Cause It won't start with the remote starter either when the problem occurs.
Danyboy

 

The remote starter should bypass the entire ignition switch so that does lead you away from that being the cause.

 

Swartlkk,
All right, ignition switch possibility tossed away. Now, you answered blazerWOOD, who seemed to have a similar problem recently, that his 'bypass module' might be the problem. What exactely is this bypass module ? Anything to do with this remote starter and anti-theft system installation ?
Danyboy

 

OK. Drove for a while again, came back home, turned it off, couldn't restart it (just fuel pump noise for 2 seconds again, nothing else. Tried with the remote starter as well, nothing.
Moved the wires close to the park/neutral switch again and tried with the remote starter from underneath, nothing.
Open the hood, heard same signal as when you open driver's door with the key still in the ignition ??? Checked this anti-theft open hood switch. Whenever hood is open, it buzzed. Removed it, sanded where it contacts the body real well, screwed back in. Tried to start the engine, it works. Seems that it will key start or remote start even if the wire connector to this switch is plugged off !
So, I imagine that driving for a while would cause a certain vibration and this connecvtion would somehow become loose and prevent from starting it again. Just a guess. Will drive the blazer all day to see how it goes.
Danyboy

 

While I was up in the artic working, a buddy took it to my mechanic and he found a faulty relay. Replaced it and everything fine and dandy. I love my Blazer again !
danyboy

 

Which relay did he replace? I just finished up replacing my LI gaskets along with the MFI upgrade and it won't start to save my ***. This is killing me...

 

You have 3 relays (little inch and a half square black plastic box) under the hood, passenger side, on the firewall. There seems to be room for a 4th one but I only got 3. The mechanic replaced the middle one. Didn't take long for him to find it. He charged me $40 including the labor so this part isn't expensive. Hope this helps you.
Happy Holidays,
Danyboy

 

I tested all of the relays and they worked fine. I pulled the #5 spark plug and found a weak looking spark. After talking to my brother who has my old blazer and my old 4.3 silverado, he asked me to replace the coil and even the ignition control module for good measure. The coil was $36 and ICM was $70 from Autozone. It was good money spent as she fired right up!

The old coil was basically destroyed an sick looking. After reading various posts on other forums it appears that if the coil gets any moisture inside of it (most likely via a crack), it will short out and not fully energize. That probably explains why it would have trouble starting on very high humid days.