98 5.7 vortec won't start in the cold, crank but no start.

[turnerg5]

When it's about 30 degrees F or lower my 5.7 will crank but not start, above 30 below 40 If I do get it to start it will pitter out for a few cranks, and then might finally grab on spit a little and then run perfect and super strong, no rough idle and no performance issues.

Has new starter, new battery, new alternator, new fuel pump relay and I can hear the fuel pump running. Haven't checked pressure yet but am assuming it's good considering how it runs after starting.

Am thinking either fuel pressure regulator or spark plugs but am not sure and would like second opinions.

 

[Schurkey]

Connect a scan tool. Verify the coolant temp sensor especially, but all the sensors and computer outputs in general.

What is the fuel pressure during the prime cycle when the key is turned from "Off" to "Run"?

How old is the distributor cap, rotor, plug wires, and spark plugs?

 

[turnerg5]

Connect a scan tool. Verify the coolant temp sensor especially, but all the sensors and computer outputs in general.

What is the fuel pressure during the prime cycle when the key is turned from "Off" to "Run"?

How old is the distributor cap, rotor, plug wires, and spark plugs?

Just talked to the previous owner and it sounds like plugs were done a couple months ago. Scan tool didn't show any codes or anything. I don't have time to check the fuel pressure or verify any sensors atm, I imagine cap, rotor and plug wires are original, not sure though.

 

[Schurkey]

Scan tool didn't show any codes or anything.

You're not looking for codes, and you won't be using a cheap piece of crap "code reader". You'd be using a real SCAN TOOL, you're looking for sensor data, the coolant temp in particular--but all of 'em in general.

 

[pitterpat]

Have you tried a new coil?

 

[turnerg5]

Have you tried a new coil?

I got her fixed now, needed a new fuel pump, filter and had a cracked line, don't buy pickups from idiots