2004 Impala 3.4l stops suddenly while idle or driving, no spark.
Thread Starter
CF Beginner
Joined: Mar 2016
Posts: 1
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2004 Impala 3.4l stops suddenly while idle or driving, no spark.
I have a problem with my 2004 Impala 3400 sfi that I need some help with.
When idling or driving for a length of time that seems to vary, but usually more than 45 minutes, the car will shut off like you just turned the key to the acc position. No check engine light, no stumbling, no drama. All the lights stay on and everything seems normal except for the car is off and won't start again. It won't start for anywhere from 3-10 to ten minutes, and then runs fine again for a while.
I have taken a video that shows that after it shuts off like this, there is no spark (the video is shaking but trust me). I've also seen twice now a good sized puff of white smoke coming from the throttle body area or towards the firewall from there, and a bit of a smell that I can't exactly locate. Also i've noticed a noise that I don't think I've heard before, it occurs about 19 seconds into the video.
I am prepared to do troubleshooting. I have a DVOM and an OBDII interface with Torque Pro for android.
The only thing changed even recently was the fuel pump and relay. I tested the fuel pressure during the no start condition and I appear to be getting fuel, just no spark. I can't get a noid light on the injectors as it looks like the whole upper intake has to come off to get at them.
My wallet is very thin and I cannot afford to take this anyplace so I'm hoping you all can help.
When idling or driving for a length of time that seems to vary, but usually more than 45 minutes, the car will shut off like you just turned the key to the acc position. No check engine light, no stumbling, no drama. All the lights stay on and everything seems normal except for the car is off and won't start again. It won't start for anywhere from 3-10 to ten minutes, and then runs fine again for a while.
I have taken a video that shows that after it shuts off like this, there is no spark (the video is shaking but trust me). I've also seen twice now a good sized puff of white smoke coming from the throttle body area or towards the firewall from there, and a bit of a smell that I can't exactly locate. Also i've noticed a noise that I don't think I've heard before, it occurs about 19 seconds into the video.
I am prepared to do troubleshooting. I have a DVOM and an OBDII interface with Torque Pro for android.
The only thing changed even recently was the fuel pump and relay. I tested the fuel pressure during the no start condition and I appear to be getting fuel, just no spark. I can't get a noid light on the injectors as it looks like the whole upper intake has to come off to get at them.
My wallet is very thin and I cannot afford to take this anyplace so I'm hoping you all can help.
CF Senior Member
Joined: Oct 2006
Posts: 464
Likes: 5
From: Massachusetts
So you say it shuts down after it gets good and hot, like after driving 45 minutes and spark goes away? My 2001 Impala LS with the 3.8L would loose a couple cylinders after 30 minutes of driving. It would run fine when cold. At first I thought it was a bad coil, but when I swapped them on the ignition module, the "bad" coil fired just fine on the cylinders it was connected to then and the one that was working stopped working when put into that position. I know what you mean about throwing parts and money at it. I changed my ignition module and the problem never came back.