99 Suburban stalls - have questions

[SAABurban]

Hi guys and gals. This is my first post. I'm new to this forum. I've been around the 94-96 Impala SS forums as well as SAAB Central. Hopefully someone here can offer up an opinion on a new problem with our 1999 GMC Suburban 4X4. I have used the search feature and have not found anything '99 specific.

Bought used 7 mos ago with 149K on the clock. We've put 20K on it. Essentially we know nothing mechanically about the vehicle. Has needed nothing until now. It is a 5.7L Vortec.

After we bought it, two incidents of stalling making a to-the-lock hard turn in a parking lot. Fired right back up.

Three weeks ago, in Friday afternoon rush-hour traffic in downtown Atlanta (stop and go) it stalled. Fired right back up.

Today while making a deposit at the bank, it stalled while sitting @ the night drop. Fired right back up.

Vehicle stalled while turning out of the parking lot. Coasted 50 yards and called the husband. Said, "might be calling you again." Fired right back up.

Conked out before I made the next parking lot (less than 50 yards) and I coasted into the zippy mart lot. Called the hub who said to pop the hood and he was on his way. He made it there in about 25 minutes, fired that mother right up, and he drove the 15 miles home without incident.

CEL does not come on. Does not lose use of electrical accessories. I read a snippet of something on another forum this evening about the ECT sensor (engine coolant temp) causing this. We don't know when this thing had it's last tune up. Factory spark plug wires. Before we get $100 worth of tune up parts, I was wondering if anyone had similar experience and the fix was the ECT sensor.

Any suggestions? Thanks in advance.

[abaird]

Just because there is no service engine light on doesn't mean there are no codes stored. You will need someone with a scan tool to see what is going on. I will guess that it is not the ECT, that would more likely cause hard starting and stalling when engine is cold. Could be the IAC not responding to changes in engine load. I got rid of my 97 k1500 with that motor when it had 136k on it and I was having problems with the EGR valve sticking closed which only caused an SES light but I suppose if it stuck open that could make it die but I think it would run rough. The bad thing is that there is a hundred things that could cause this, faulty fuel pressure regulator, MAP sensor, ignition coil, O2 sensors,...

Any way, I would suggest you have someone read the codes(if there are some) there are places that do it for free. That will hopefully point you in the general direction. Post back if you find anything out.