3800 Starts then shuts off

I have a 1997 Pontiac Grand Prix GT, I just intalled a 3800 from a Monte Carlo. Engine Code is K, and it is a L36

Last night I turned the key and it started !!!!!!! But then it immediately shut off. I did this about 15 times, every time I had the same exact result.

And ideas?

What happens when you give it some gas?

Have you tried unplugging the MAF?

Are you sure there are no vacuum leaks?

I gave it gas one time and it seemed to back fire - had a pop like back firing. I was sitting in the driver seat, touching the pedal.

It was late, I was in the garage by myself, my son, my help was in bed.

I did not unhook anything, nor did I see any vacuum leak.

I was happy it started, sad that it did not stay running though. It was time for me to goto bed...

Check for vacuum leaks, especially the big vacuum hose for the brake booster where it hooks to the upper plenum. Your symptom is classic for a major vacuum leak.

That big Vacuum hose could be the problem, it was unhooked, my son was looking at it...hmmm....I would think he hooked it up but sitting here at my desk at work does not help.

Now if the clock would just start ticking faster.

Thanks Richtazz !!!!!!!!!!!!!!

The big vacuum hose for the brake booster where it hooks to the upper plenum was the problem !!!!!!!!!!!

We, my son and I, think possibly when we rolled the engine forward to install the power steering pump, exhaust, last bolt into the trans that this make have popped off the plenum. Or someone may have just not gotten it connected.

He drove the car to school today, last time he drove it was February 20th.

Thanks again for the advise!

No problem you're very welcome, that's what we're here for. Thank you for letting us know your issue was resolved, as it may help someone in the future doing a forum search with the same problem