04 Trailblazer stalls at red lights

Hi,

Once last summer and now twice this summer, our 04 Trailblazer LT has stalled when sitting at red lights. The car just shuts off. Turning the key to the off position and starting the car again works fine.

It only seems to happen in hot 90° weather after driving around for a while.

Any thoughts?

Many things can cause this, I'd start with cleaning the throttle body.

Many things can cause this, I'd start with cleaning the throttle body.

Thanks dude. That's probably it. The throttle bore was nasty.

was this issue resolved? I too have this problem and as common as it is, finding the solution is very difficult. I have changed the clutch fan and the "cam sensor". The next step is the o2 sensor and/or the throttle body.
If anyone have a solution for the stalling at idle, i would greatly appreciate the help.

That is what i want to know. I have cleanded my throttle body. It worked for a few months, but then it started stalling again while at red lights. Now it even stalls while its is in PARK. It all started when at night i noticed when i got off the gas when coming up to a red light and the headlights and dashboard would go dim and brighten back up and then dim again. while this is going on, the rpms is dropping and shooting back up.

Bet this is your problem,
My brother-in-law brought me his 2004 Trailblazer that had an extremely rough idle and would die if ya thought about the air conditioner and all! So he had replaced the cam sensor DIDNT HELP, he replaced the spark plugs DIDNT HELP, he replaced the fuel filter DIDNT HELP, so he asked me about it says alot of people are having a rough idle problem so after more searching on the problem I ran across a fella talking about the CAM ACTUATOR SOLENOID and explained all about what to look for and such and low and behold new solenoid later purrrrrs like a new one!!! In case anyone wonders where it is look right above the power steering pump there is a plug in the side of the engine there with electric wires running to it. One of the signs of being bad is oil inside that 2 wire plug just pull it off and look in it. Now to remove it you will have to take the power steering pump loose so it will move back out of the way so you can pull the solenoid out of the engine if ya get it out look on the end there are grooves running around it with little screens on them see if any are gone or coming apart, this usally sets a P0016 code which is stuff interfering with the sensors inside. If there is any oil in the plug or any screens missing then it will have to be replaced, if you are experiencing a rough idle but runs fine usally otherwise then 9 out of 10 this is your problem expecially after pulling all your hair out and replacing half the engine....LOL well good luck L8terrrrrrrrrrrrrrrrrrrrrrrr

Good info but as usual proper diagnosis will usually find the root cause, a full scan for pending or present codes would have pointed to the solenoid..

He had it scanned and ...Nothing... all it showed were the P0016 code. It said nothing about the solenoid and half the mechanics didnt know about it either until after the fact.

i would check the idle air control (IAC) valve. sometimes these things get crud on them and restricts the air flow when you let of off the gas. every time i see this, i just clean the vlave and its seat and the problem is fixed. just a thing to check on.

0016 points to a cam synch problem, they just didn't research to usual cause of this code, it was right there.

0016 points to a cam synch problem, they just didn't research to usual cause of this code, it was right there.

Oh I agree I am just saying we had to track down this problem we couldnt rely on the mechanics here at the dealer they didnt know (or didnt care) about squat.

I also have an 04 Trailblazer which is experiencing pretty much the exact same thing being described by others in this forum. My TB's SES light came on over the weekend & has begun to stall at stops after anything more than 5-10 mins of driving. TB will run just fine after start up initially or even a re-start, until you drive about another 5-10 mins, then the issue seems like it creeps back up. When issue occurs the engine begins to shake & you can feel it get worse as you come to a stop. Acceleration is very shaky as well as though the engine is sputtering. Additionally, my A/C & circulation button will not stay lit, instead they flash a couple of times once pressed then go back out....I took TB to AZ & my codes were P0134 & P0130. AZ seemed to think that those codes pointed to o2 sensor but based on symptoms tough to believe that my root cause

DTC P0130 HO2S Circuit Closed Loop (CL) Performance Bank 1 Sensor 1
DTC P0134 HO2S Circuit Insufficient Activity Bank 1 Sensor 1

Usually, these DTC's indicate a lazy or inoperable O2 sensor, which means the PCM is unable to control fuel trim in closed loop.