Looking for some advice. I have a 2000 blazer. The other morning it got really cold out and the truck would not start. It cranks, has 58-60psi of fuel pressure, i've tried spraying fuel, brake parts cleaner and ether in the upper plenum and the motor will not light off. I pulled all the wires off the cap and rotor and stuck another wire with a spark plug on it off each spot on the cap. All I got was a faint yellow spark. I figured maybe the coil was going bad so I bought a new coil and nothing. Something changed overnight sitting in the cold. Any ideas?

 

Make sure the battery is fully charged.
Fuel pressure is borderline low: Must be 60psi to 66psi. May be due to a low battery. Orange/yellow spark is a problem. Could also be due to a low battery. When was the last time it had a new AC Delco distributor cap & rotor? How old, how many miles, are the plug wires?

 

I put a new cap and rotor on last year. battery is charged and is on a charger while I was cranking all this time. I know the injectors are firing because the oil smells fueld down while i've been trying different things, checking plug wires for spark ect. wires have been on for about 20k miles. I pulled one off the drivers side that was easy to get to and the sparked looked the same on that one vs a wire with a plug attatched to it off the rotor as well

 

What brand was the cap & rotor that you installed? These things are fussy when it comes to tune up parts. Aftermarket caps don't last, especially if camshaft retard is not within specs.

 

I had the same problem (brand new aftermarket cap and rotor would not start if cold or raining). Was the cap and rotor. My Blazer will not start good if I use aftermarket parts. Put AC Delco cap and rotor and it starts and runs fine.

 

delco. I tried a new coil didn't help. I took my ICM to the parts store and had a friend test it and it failed but then 2 more failed off the shelf their machine was messed up. I put a new one on and the engine acted like it wanted to fire. Gave it a shot of ether and it lit right off. It sat over night (15-20 deg) I just tried it again and lit off just fine on its own. I'm not fully convinced that ICM was the problem

 

The module testers at the auto parts stores, as you found out, are worthless. Best to troubleshoot them on the vehicle with a DVOM.

If it fires up after a shot of carb cleaner, it indicates a lack of fuel. Avoid using ether, it's far too dangerous for bystanders and for the engine. Recheck fuel pressure with a fully charged battery. Ignition ON, engine OFF, fuel pump running: pressure must be 60psi to 66psi and it must remain above 55psi for at least 10 minutes after the pump shuts off. Post your results.