need help on a 2005 impala with 3.4

[Silent viewer]

i know this is not a g body but i am at the point of taking the car to the shop and thats a last resort for me. the car started out dieing randomly and hard starts, it has gotten to the point that i cant even keep it running with my foor on the brake and giving it gas. it runs rough and takes me pushing all the way down on the pedal and cranking for 20 seconds before it stutters and starts. i have checked the egr, the iac, fuel pump and the cat. replaced fuel filter, air filter and plugs also. i am leaning at trying a cam sensor and crank sensor at this point... anyone have any ideas or maybe confirm my symptoms to one of those sensors? the car has 80k on it and i bought it for the other half so i wouldnt have to work on a car for her after having several beaters so i would have more time for my projects.... sure enough the warantee ran up in january. i am trying to pick up a lsx 5.3 motor this weekend but my lsx plans may be put on hold if i cant get this car fixed before sending it to the shop on firday 🙁 any help or suggestions are welcome!

 

[beermonkey9417]

check the engine temp sensor. mine went out on my satty and it kept telling the computer that the engine was 0 degrees all the time so it kept dumping fuel in the tb and flooding the engine. get it tested and find a impalla forum for better help.

 

[GP403]

It's not throwing any codes out? I'd find a good obd-ii scanner and see what the computer has to say before tearing into replacing random things.

 

[beermonkey9417]

the scanners tell you what codes have been thrown, but not why. its how you intrepret those codes to find out how everything got started. i had a buddy with a late 90's jetta that was throwing o2 sensor codes and showed 180something missfires in the #3 cylinder. it turned out to be his crank position sensor. so take it to a mech. you KNOW is good.

 

[GP403]

Yeah it isn't perfect, but most of the time it'll give you something to go off of. They are a lot better now since the first ones came out in 96. I had a 96 saturn that would periodically throw 'cam position sensor' codes, even though it didn't have a sensor there(!) and it otherwise ran fine. Should have put a *YMMV* on that one 😀

 

[Silent viewer]

i had codes pulled and it said engine mis fire and maf but the maf was from me pulling it off to see what happend while it was running. from what i read online those 2 sensors are most liekly the cause. if not i have a appointment with a diagnostic machine on friday 🙁

 

[1badbu]

For sure have codes ran.
Almost sounds like a TPS (throttle positioning sensor) if it won't stay running while holding the brake.The TPS acts sorta like a full time choke.From what I was told it works with the map sensor,and fuel metering on the fuel rails.
But I've had a CTS (crank trigger sensor) go bad on a 3800,and it would run fine for a while then just die.Wait about 15-20 mins. and fire right back up.
The TPS's I've had go bad were on 2.5l's ,with throttle bodies and they acted like what your desrcibing.Their cheap and easy to replace.
Good luck :!:

 

[axisg]

naioa.com

Could be any number of sensors from the cam, crank or even the fuel pump or PCM. Great bunch over a www.naioa.com

 

[Pontiac455]

Is it fine when its cold? If so replace the ignition control module... Check yer fuel STFT of the 2 banks on the scanner c if its addin or pullin fuel away? Then we can go from there. Had alot of thease engines that needed injector cleaning. it all depends on the fuel trim...

 

[pontiacgp]

unplug the mass air flow and see what difference that makes..it'll run better if that's the problem