2003 Chevy Astro Van - 4.3L V6
Hi Scotty, I recently discovered and subscribed to your amazing YOUTube Channel. I have quick question: I've owned a 2003 Chevy Astro Van 4.3L V6, 120k Miles on it for about 10 years. Recently I discovered that now when I get on the Freeway and have to punch it the engine starts to shake and loose power along with a funky smell. If I let off the throttle and feather it for a minute or 2 it starts to run fine again, as long as I don't have to get on it. Otherwise around town it runs like a champ. The problem only rears its head when I have to really accelerate. Same thing everytime. Any ideas on what is going on? and how to fix the problem? Any help is much appreciated Thanks - Anon
You don't need to repeat your reply four times. We can all see it.
So what do you mean the codes are "vague". Diagnostic codes are usually pretty precise with what they're reporting. Please tell us what they are.
A flashing malfunction light is desperately trying to get your attention because you're probably ignoring a major problem. It means "hey you! Stop!". you've probably got a bad misfire and should address it before causing more damage.
Thank You, New here, but appreciate the education...
Well if you get a funky smell it could be the catalytic converter is starting to clog up when you accelerate really fast. It'll make it act up but if you go slower it won't. I would start my checking that
Thank You Scotty, I will check the catalytic converter. Someone suggested it could be a Engine misfire? Does that make any sense to you?
Codes are vague at best, Forgot to mention the check engine light starts flashing when this whole scenario plays out when trying to accelerate hard at freeway speeds. Once I stop accelerating and feather the gas pedal for 30 seconds or so the engine stops shaking the funky smell goes away and the CEL goes off like nothing happened... It's the only time I've ever seen the CEL flash at all, usually if there is any other problem the CEL goes on and stays on until whatever issues is fixed.
Someone suggested it could be a Engine misfire?
Did that "someone" also mention that if you had misfires it would show up when the vehicle is scanned for codes and data? Has that been done?
Codes are vague at best, Forgot to mention the check engine light starts flashing when this whole scenario plays out when trying to accelerate hard at freeway speeds. Once I stop accelerating and feather the gas pedal for 30 seconds or so the engine stops shaking the funky smell goes away and the CEL goes off like nothing happened... It's the only time I've ever seen the CEL flash at all, usually if there is any other problem the CEL goes on and stays on until whatever issues is fixed.
Do you have any codes stored, represented by the Check Engine Light? If your CEL is on, there are codes stored.
Even if the light is not on there can be pending codes stored.
Codes are vague at best, Forgot to mention the check engine light starts flashing when this whole scenario plays out when trying to accelerate hard at freeway speeds. Once I stop accelerating and feather the gas pedal for 30 seconds or so the engine stops shaking the funky smell goes away and the CEL goes off like nothing happened... It's the only time I've ever seen the CEL flash at all, usually if there is any other problem the CEL goes on and stays on until whatever issues is fixed.
t's the only time I've ever seen the CEL flash at all
When the check engine light is flashing it means "stop driving immediately" to avoid damage, frequently due to heavy misfires. You need to dig into the live data.
Thank You!
2003 Chevy Astro Van - 4.3L V6
Hi Scotty, I recently discovered and subscribed to your amazing YOUTube Channel. I have quick question: I've owned a 2003 Chevy Astro Van 4.3L V6, 120k Miles on it for about 10 years. Recently I discovered that now when I get on the Freeway and have to punch it the engine starts to shake and loose power along with a funky smell. If I let off the throttle and feather it for a minute or 2 it starts to run fine again, as long as I don't have to get on it. Otherwise around town it runs like a champ. The problem only rears its head when I have to really accelerate. Same thing everytime. Any ideas on what is going on? and how to fix the problem? Any help is much appreciated Thanks - Anon
Did you check or replace your spark plugs in 10 years? Under heavy acceleration, the spark plugs must work harder and they require precise sparking, or the engine will misfire.
symptoms seem like a clogged cat, but obviously, you would need to verify, as it could be something else.
Codes are vague at best, Forgot to mention the check engine light starts flashing when this whole scenario plays out when trying to accelerate hard at freeway speeds. Once I stop accelerating and feather the gas pedal for 30 seconds or so the engine stops shaking the funky smell goes away and the CEL goes off like nothing happened... It's the only time I've ever seen the CEL flash at all, usually if there is any other problem the CEL goes on and stays on until whatever issues is fixed.
Frustrated Update: Checked for clogged cats as suggested, That was Not the problem, but thank you for the suggestion. Fuel pressure checks out as normal while driving. After researching about the factory fuel injectors for this make and model I found a lot of problems related to the oem fuel injectors and found several references to an updated version available. Running out of ideas I decided to replace the fuel injectors and (Spider) with the All new updated version. Unfortunately after all that the same problem still persists with hard acceleration from 50 - 70mph. The CEL flashes, stutters, loses power, and a funky smell, and I have to feather the throttle for a few seconds and it will recover and drive normally until I need to hit the throttle again hard for passing etc. and it all happens again... I'm fresh out of ideas. any thoughts or help is much appreciated.
any thoughts or help is much appreciated.
We're still waiting for those codes. Thanks.
Also live data as Chuck mentioned. Fuel trims, etc.
You should be focusing on that rather than throwing random parts at the problem.
also, have you checked out the misfire troubleshooting in our FAQ?
I asked my mechanic about codes, and he said that there were no codes. Despite all the fireworks. The CEL stops flashing and goes out after a few minutes of normal driving, and acts as normal. when he plugs into my vehicle it has no stored code. It's very weird.
I asked my mechanic about codes, and he said that there were no codes. Despite all the fireworks. The CEL stops flashing and goes out after a few minutes of normal driving, and acts as normal. when he plugs into my vehicle it has no stored code. It's very weird.
So, have your mechanic drive with you while getting on the highway. If you can reliably trip codes, do it with a mechanic sitting next to you. He can also give you more insight to your problem, if he's a true mechanic.