2004 Monte Carlo SS L67. 194,700 miles.

I have just replaced the LIM gaskets and have new injectors also.
Put it all back together a few days ago and did some limited driving to break everything back in. Sounds great.
Last night, wife and I go get a quick dinner and drive back home. Radio was on and all seemed okay.
While on the interstate, I try to accelerate to pass a big rig and the car seems to "bog" down as I speed
up.
Then the car shuts down and luckily I had enough speed to get to the exit and die on the access road.

Lights and all electronics were working but it would not restart. Engine would crank. Lights dimming severely.
Voltage was showing 11.9 but would drop to 7.6 while trying to start it. Engine temp was about 170 degrees
and I didn't notice anything leaking.
I thought maybe the alt belt had come off but it was all still in place.
Got towed home and left it in the driveway.
Started up fine this morning.
WTF?

I will remove the battery and have it tested today and just ordered a new ALT.

Thoughts?

 

Im currently having a similar issue. Only difference is mine wont crank at all. Ive had this problem for years actually but only THIS time it wont start up the next morning. Im being told its the security system (which probably isnt your issue if you have crank) and have been told that in the past.

More relevant to your issue now, it could be one of the sensors on the TB or the MAF. Could be the crank position sensor. Ive heard once these start acting up, itll give you problems when the engine is up to temp but once it cools off its like the problem was never there.

I should be hearing about my car today (guys had it forever now) and if theres anything I think can help, ill post back.

Im sure someone else with some better info will be around to help shortly.

 

Talked to a mechanic friend of mine and he suggested that it was the fuel pump.

So ... ordered one from OReilly for 157.00 and a new fuel filter.
The fuel pump was a PRECISION brand that is made in China. The one thing they didn't tell me was that I would have to do some rewiring of the pump and get a new lock collar. When I took off the cover I think I found most of the Kansas dirt outside of Kansas.

 

Lol WOW! You got it taken care of tho?

 

Wow, that is a lot of dirt!

 

So MY problem turned out to be an immobilizer was installed in my car. Must have been YEARS ago as the people I bought the car from have no idea about it.