u/FWbmw801

I have a 2002 Impala LS with the 3.8L engine and I am stumped on what the issue is. It has an intermittent stall issue and I've tried multiple things. I'll go over the recent events. It started out not starting and then after multiple primes it would start. I assumed fuel pump and replaced it. But then it wouldn't start the next day followed by it restarting only to die mid drive. I thought maybe fuel filter was clogged and changed it also but the issue persisted with it stalling out mainly during idle. I then changed the ignition pack and module. Still, it idled weak and would stall so I changed IAC. Here is when I noticed the first improvement. It idled better and I took it for 2 short trips with zero stalls. However next day it stalled after a few mins idling. I then cleaned the throttle body. Still it continues to stall and even worse, now it sometimes runs really rough sounding like a warbird engine if you know that sound. I'm thinking it's some kind of vacuum or fuel related issue but I'm really not sure. I asked a pro mechanic friend and he suggested a manifold gasket leak and that it needs to be smoked. I hesitate cause I'm broke and worried about driving it to the shop. I also got a Bluetooth scanner and ran some live diagnostics. From what I see the MAF is running normal but the long term fuel trim is showing -15 to -20. I think that means it's running rich which is the opposite of a vacuum issue. It runs better with more throttle though, 1500 rmp runs smoother than idle and even turning on ac improves it slightly.

When it dies its usually like a struggle where it shudders and rpm jumps around before death though a couple times it just straight died.

I'm really sorry if you read all that but any input on what you think it is could be is helpful. I'm hoping someone recognizes these symptoms and knows the fix so I don't have to go to the shop. Thanks so much

I have a 2002 Impala LS with the 3.8L engine and I am stumped on what the issue is. It has an intermittent stall issue and I've tried multiple things. I'll go over the recent events. It started out not starting and then after multiple primes it would start. I assumed fuel pump and replaced it. But then it wouldn't start the next day followed by it restarting only to die mid drive. I thought maybe fuel filter was clogged and changed it also but the issue persisted with it stalling out mainly during idle. I then changed the ignition pack and module. Still, it idled weak and would stall so I changed IAC. Here is when I noticed the first improvement. It idled better and I took it for 2 short trips with zero stalls. However next day it stalled after a few mins idling. I then cleaned the throttle body. Still it continues to stall and even worse, now it sometimes runs really rough sounding like a warbird engine if you know that sound. I'm thinking it's some kind of vacuum or fuel related issue but I'm really not sure. I asked a pro mechanic friend and he suggested a manifold gasket leak and that it needs to be smoked. I hesitate cause I'm broke and worried about driving it to the shop. I also got a Bluetooth scanner and ran some live diagnostics. From what I see the MAF is running normal but the long term fuel trim is showing -15 to -20. I think that means it's running rich which is the opposite of a vacuum issue. It runs better with more throttle though, 1500 rmp runs smoother than idle and even turning on ac improves it slightly.

When it dies its usually like a struggle where it shudders and rpm jumps around before death though a couple times it just straight died.

I'm really sorry if you read all that but any input on what you think it is could be is helpful. I'm hoping someone recognizes these symptoms and knows the fix so I don't have to go to the shop. Thanks so much.