No start when temperature warms up

kozmonot71

My 99 Suburban with 135,000 miles starts great if the outside temp remains consistent. For example, two days ago it's was -2 and it started right up. By the afternoon it was 20 degrees in the sun and it just would not start. It cranks over just fine. Also if I were to start it up on a cold day and drive it to the store, it's hard to start when I come back out after a bit. I can even start it, let it warm up, shut it off for ten minutes and it struggles to start. I usually turn it over twice, wait 30 seconds and repeat usually by the third try it starts. But the outside temp change? It may be days. I've heard distributor to computer. Any ideas.

thecardoc3

The only idea that really will give you an accurate answer. It must be tested while the problem is occurring.

Are you losing spark, injector pulse or both? What is the fuel pressure when the problem occurs? Are there any codes setting? If so what are they? Do you have a scan tool that will display serial data? If so what are the fuel trims and IAC counts when running normally. What are the IAT (intake air temperature) and ECT (engine coolant temperature) sensors reporting when the car is hard to start?

The real list of all of the things that can cause the symptom as described is longer than you want to imagine and the most expensive way to approach this is to just try tossing parts.