'07 Intermittent Hot Start Problem

[compyelc4]

Anyone experienced this problem? Recently purchased '07 LS3 roadster with 7,500 miles. Starts and runs great except sometimes cranks for 3-4 seconds before startup when allowed to sit for a couple of hours when ambient temp is around 90 degrees F. It does not do this for every cold-soak start but it seems to be doing this more frequently now that it's been in the 90's for a few weeks. Leaking injector, fuel pressure loss. I can't find a tech bulletin for this problem.

If I have an injector leakage or other fuel pressure problem is a fix at a dealer going to cost me my first born? I'm new to C6's. Still have my '95 C4 and it has been bullet-proof. Not use to problems with a Vette.

Also I've noticed my idle is 500 RPM when warmed up. Is this about normal? Seems a little low but engine idles pretty smoothly just the same.

Thanks,

 

[tim414]

Anyone experienced this problem? Recently purchased '07 LS3 roadster with 7,500 miles. Starts and runs great except sometimes cranks for 3-4 seconds before startup when allowed to sit for a couple of hours when ambient temp is around 90 degrees F. It does not do this for every cold-soak start but it seems to be doing this more frequently now that it's been in the 90's for a few weeks. Leaking injector, fuel pressure loss. I can't find a tech bulletin for this problem.

If I have an injector leakage or other fuel pressure problem is a fix at a dealer going to cost me my first born? I'm new to C6's. Still have my '95 C4 and it has been bullet-proof. Not use to problems with a Vette.

Also I've noticed my idle is 500 RPM when warmed up. Is this about normal? Seems a little low but engine idles pretty smoothly just the same.

Thanks,

I had a '09 LS3 and did same thing....I am NOT saying it had to crank allot, but it did turn a couple extra times when in that condition. Never developed into any problem. I sold the car with 8200k mi and got a '10 LS7....it does the same thing and has 865 miles now....might want to run some fuel injector cleaner through tank gas.....I use and I think allot of guys aqlso reccomend Chevron's Techron....that stuff works good in my Vette and Yukon....oh and yes, mine both idle and idled (post '09) the same at around 450 rpm

 

[PeterG]

This evening when it was about 82 degrees out, after driving for 30 minutes, I shut my '07 off for 10 minutes. The restart was weaker sounding and took longer than usual.

This was with my two-week old battery that has been starting it with a solid-sounding crank not taking as long to start as it did this evening.

I attribute this weaker and slower start to the hot engine. The water temperature was 224 degrees and oil 226 degrees.

For now I call this "normal" or, at least, nothing to worry about.

 

[tim414]

This evening when it was about 82 degrees out, after driving for 30 minutes, I shut my '07 off for 10 minutes. The restart was weaker sounding and took longer than usual.

This was with my two-week old battery that has been starting it with a solid-sounding crank not taking as long to start as it did this evening.

I attribute this weaker and slower start to the hot engine. The water temperature was 224 degrees and oil 226 degrees.

For now I call this "normal" or, at least, nothing to worry about.

I do not know if cranking "slower" is correct. I do not think mine crank slower. You might want to have checked out and ensure the negative (grounds) are all secured. There are a couple that are real important to my understanding. Maybe C4C5specialist will see this and chime in.

C4C5Specialist....see this????

 

[compyelc4]

Corrected: '07 Intermittent Hot Start Problem

I got lucky and corrected this. Poured in 1 container of Lucas Fuel Injection Cleaner. Problem fixed in less than 1 day.

 

[c4c5specialist]

HI there,

It would be suggested to use top tier fuels to prevent this type of concern.

Lucas will not fix the concern that fast, what was done was a change to the fuel entering the combustion chamber.

Allthebest, c4c5

 

[compyelc4]

Yeah, it really surprised me too. I purchased the car out-of-state with 7,700 miles on it. I don't know what type of fuel the previous owner used but I suspect the BMW dealer from which I purchased the car did the fill up. I did not notice a problem until about a 1,000 miles later By then I had run about 3+ tanks of Shell Premium through her. She was getting pretty low on fuel so I added about 15 gal. of Shell Premium and a container of the Lucas.

Sooo, I was running Premium blend fuel when I noticed the "leak down". In the back of my mind I suspected a hang-up in the tank anti-drain-back valve, or whatever it is called. Well, this one is a real mystery then.

Thanks for the the feedback though.