I have a 2001 gmc 1500 with a 4.8L engine and around 145,000 miles on it. I have a small problem that for lack of time I have been ignoring for a couple years. There has been no check engine light. but now that the cold weather is back I have to start it twice, the first time it will stutter and stall, and then the second time it starts normal and runs fine. I should add that this only happens when it sits over night. I am hoping someone has seen this before, It will save me a the diagnostic time as I do all of my repairs myself.
What happens when you go from the off position of the ignition switch to the position right before start, do that a couple of times and then start it?
The fuel line is supposed to have pressure on it when it starts. When you rock the switch to that position right before starting, it pressurizes the line. There should be fuel left in the line and the pump briefly running just brings it up to normal pressure.
It could be that this is not happening or that the fuel bleeds into the cylinders over night because one of the fuel injectors is leaking a little.
For starters, try running some Techron fuel additive through the fuel system. If it is a bleeding injector, that may fix it.
That would be the simple cheap thing to try first.
When starting cold, do you make any effort to rev the engine? If not, you might try doing so. Try it and post back.
I have tried revving the engine, and it doesn’t do anything different. I tried this morning turning the key to ignition 3 times before I started it, the fuel pump ran for aprox 2 seconds each time (it was hard to time being so quick) but it didn’t seem to start any better on the first try.
There are several conditions that can develope and cause your starting problem and you can test and inspect to determine which are/is the cause for you But for several different issues a product like Techron can significantly improve the situation for a few dollars and little incomvenience so you might do well to add a bottle to the next few tanks full and note any improvement. Although attempting to rev the engine while starting didn’t seem to help, cleaning the throttle body and idle air control might be beneficial.