1998 Suburban Starting Issue

[rl_sd]

ok @Jeremy airjer W..... Here is a new one for you.

 

I have a 1998 suburban that I picked up a few years ago. It has started flawlessly the past two winters, but started acting up this winter. If it is warm out (+25°) it was popped right off. When it gets down to the single digits though, it will just crank and crank. The motor seems like it is spinning over plenty fast, but it won't fire. If I plug in the block heater for a few hrs it pops right off. I change the fuel filter and replaced the fuel pump in Nov 2016. I have 60 psi at the rail, so I don't think that it is fuel delivery issue. My question is.... Does the computer do anything goofy with the injection system depending on air temp and/or coolant temp? It has the 5.7 with the spider injectors. The one trick that I have learned to get it to pop off everytime is to let it turn over for half a second... stop ... turn over half a second... stop.. and on the third time it pops off and idles perfectly no matter how cold. Thoughts?

[Jeremy airjer W]

Put your fuel gauge on in the night before. Then check your fuel pressure in the morning when you try to start it. I suspect that your fuel pressure is a tad to low to get the mechanical poppets to open. As little as 1 psi below the minimum is enough to cause a no start.

 

Also when it does not start try adding a couple of quick shots of carb spray into the throttle body. It it pops off and continues to run you just verified it is a fuel issue. 

[rl_sd]

13 hours ago, Jeremy airjer W said:

Put your fuel gauge on in the night before. Then check your fuel pressure in the morning when you try to start it. I suspect that your fuel pressure is a tad to low to get the mechanical poppets to open. As little as 1 psi below the minimum is enough to cause a no start.

 

Also when it does not start try adding a couple of quick shots of carb spray into the throttle body. It it pops off and continues to run you just verified it is a fuel issue. 

 

Ill give that a shot.... any idea why it starts right up when it is plugged in? I wouldn’t think having a warm block would change my fuel pressure at all