2002 Chevy Trailblazer LTZ 4.2L 183,000 miles.
Hey everybody, my Trailblazer dies when I come to a stop. Sometimes immediately and sometimes only after I'm stopped for 4 or 5 seconds. It started about 3 weeks ago and has gotten progressively worse. It doesn't do it every time but about 4 out of 5 times now. when it'* idling and not dying it'* very smooth, it'* just like the key is turned off. I can restart it and it starts right up.
but when I accelerate from a dead stop it hesitates for a second like it wants to die and then takes off. At speed everything seems normal. It has done the hesitation for over a year now, I haven't been able to fix that.
I had a P1440 code evap leak for the past year but could not find the problem, check engine light was on the whole time until about a month ago, then light went out and code is gone. go figure. Then this problem starts.
Check engine light is off, I have 3 codes.
B1480 Battery run down protection circuit
B1850 and B1860 Lumbar horizontal and vertical circuit sensor malfunction.
battery is at 12.5v engine off and 13.8v engine running. starter does seem to crank slow.
all lumbar functions work.
let me know what you think,
thanks.

I forgot something. most of the time I come to a stop, the tach goes down to 700rpm and then the engine just shuts off. But yesterday as I was coming to a stop I got to about 10 mph and the tach dropped really fast and it felt like the engine was going to die and a warning message popped up on the IP that said "turn engine off". I reached for the key but just that fast the engine'* rpm went up to 7 or 800 and the message disappeared. the tach had dropped down to about 400 when this happened. that'* the only time this has happened.

I'd look at the throttle body to see if it is gummed up, then look at fuel pressure.

throttle body is very clean. I put a new fuel pump and fuel filter in it 4 days ago. I will check the pressure tomorrow. about a year and a half ago I took the throttle body off and cleaned it. I've never seen an electronic throttle before. is it ok to manually open the throttle plate on it to clean it?

I was checking data streams on my scan tool and everything looked normal except my fuel trims were all over the place.
I can't remember LTFT'* but the STFT'* were going from +8 down to -20 when I revved it up.

How old is the battery?

How many miles on the spark plugs?

What other repairs have you done to it? . . . and when?

I bought 18 months ago. it had been sitting for 2 years. It had 178,000 miles on it. 183,700 on it now. when I bought it I replaced plugs, coils, fuel filter, air filter, 2 O2 sensors, and cam actuator valve, took off and cleaned the throttle body, put new valve cover and intake and exhaust gaskets on it. kept getting code for large Evap leak. thought I found the problem and fixed leaking hose. didn't fix it. replaced vent valve, purge valve and Evap pressure sensor in gas tank, mostly in summer of 2022. didn't fix it. check engine light has been on for last year, but it went out 3 weeks ago.
last week I replaced the evap canister and fuel pump.
Tonight the check engine light came back on. only code is 1440 Evap system problem.
I know I've been throwing parts at it but I don't think it was taken care of by previous owner and I plan on keeping it for a long time. When I bought it the spark plugs were a nub, probably original. when I replaced the gas filter I cut open the old one and it looked like it had mud in it it was so dirty!
could it possibly be a gummed up cam actuator valve? or variable valve actuator sprocket? when I changed the valve cover gasket the engine looked very dirty like the oil hadn't been changed regularly.
I know it'* hard to diagnose stuff over the internet but you guys are way more experienced than me! Thanks for any input! I'll keep you posted. BTW haven't had time to check fuel pressure. I'll let you know what I find.

I mention the actuator valve and VVT sprocket thinking if they aren't working right the ECM doesn't know what or where to set the timing so when I come to a stop it dies.

Thanks for the info. I'm looking forward to knowing the fuel pressure, especially at the the it dies if possible.

If the cams were ending up too far different than what is commanded, there'd be a code set for it.