Intermittant Stalling

[madisonguy]

I've seen others having this same issue. 2000 Bonneville SSIE with just over 200,000 miles. It randomly stalls (doesn't seem to make a difference cold/hot, highway/idle, etc.). It normally starts right back up, but sometimes might need to crank for 5 seconds or so. I've replaced the fuel filter and spark plugs, with no change. Cleaned the MAF sensor and throttle body, and it seems to be better after that, but has still stalled a couple times.

I checked the fuel pressure at the rail. Just turning the key on (car not running), the pressure is at 8 psi. I started the car without touching the gas, pressure stayed at 8 psi. After a few minutes, I revved the engine a few times, fuel pressure went to 40-45. I also noticed the fuel pressure goes up with rpm. As I rev the engine, the pressure will vary from 40-55, then settle back to just over 40.

Is the fuel pressure supposed to vary with engine rpm? If this is not normal, would this be fuel pump or regulator?

[01bonneSC]

I've seen others having this same issue. 2000 Bonneville SSIE with just over 200,000 miles. It randomly stalls (doesn't seem to make a difference cold/hot, highway/idle, etc.). It normally starts right back up, but sometimes might need to crank for 5 seconds or so. I've replaced the fuel filter and spark plugs, with no change. Cleaned the MAF sensor and throttle body, and it seems to be better after that, but has still stalled a couple times.

I checked the fuel pressure at the rail. Just turning the key on (car not running), the pressure is at 8 psi. I started the car without touching the gas, pressure stayed at 8 psi. After a few minutes, I revved the engine a few times, fuel pressure went to 40-45. I also noticed the fuel pressure goes up with rpm. As I rev the engine, the pressure will vary from 40-55, then settle back to just over 40.

Is the fuel pressure supposed to vary with engine rpm? If this is not normal, would this be fuel pump or regulator?

Pull the vacuum tube of the FPR, if you can smell gas, FPR is bad.

[madisonguy]

I didn't smell gas in the FPR, so I ended up changing the fuel pump and haven't had a problem with it since. Thanks for the help. Since replacing the fuel pump, my displayed gas mileage on the DIC is off. It reads about 10MPG higher than actual (before it was right on). What sends the computer the information on how much fuel is being burned?