Help With Cold Starting Issues...

[goat19642004]

My 1999 Tahoe with 5.7 engine does not want to start when temps. drop below 40 degrees. The engine cranks without any signs of firing then finally stumbles to a stable idle. When temps are above 40 degrees it starts without any hesitation. I checked the fuel pressure and it is 62 psi when the key is on and 55 psi while running. I also monitored the pressure after I shut the key off and noticed no drop in pressure after 1/2 hour.

 

The distributor and wires were replaced along with plugs, fuel filter and air filter. The truck has 86,000 miles on it and also has a Wait for me tune.

 

Can anybody point me in another direction?

[minibike132]

Might start with a fuel sample as long as you have the gauge out? Put some of your gas in a glass jar and set aside for awhile to make sure there is no water separation.

[goat19642004]

Might start with a fuel sample as long as you have the gauge out? Put some of your gas in a glass jar and set aside for awhile to make sure there is no water separation.

 

I've had this problem since winter started. I have even tried other brands of gas and additives.

[goat19642004]

TTT

[fixitmann]

John, does it smoke signifigantly after it starts,From like excess fuel? IF it does most likely electrical like maybe sluggish oil pressure switch not giving pump current till pressure from cranking overcomes resistance or maybe ECT malfunction not allowing cold start fuel enrichment.If it dont I would put my money on a fuel issue. Kinda hard to diagnose without more info.Scan it first make sure no codes.MIL could be activated with no light on.