The good news - my Bonneville did an 8000 mile cross country trip no problem.

The bad news, she recently started giving me stalling problems. It started as throwing a code stating that I had a hose cracked, cracked UIM, or bad MAF, etc. The UIM is dorman (full change out, blah blah), checked the torque and for cracks - negative. Checked all hoses - negative. MAF under microscope -negative.

Since... the car has been starting up and idling rough usually, either increasing the rpm automatically or by me, until it settles down to a good idle. When driving down the road or highway speeds, the car is perfect. When I begin to brake the rpms drop to almost stall, recover, and repeat (oscillate) until it usually stalls out. Starts again with usually no problem (until the next stop light).

-Doesn't matter if engine is hot or cold
-Intermitent - does not do it all the time, but is usually frequent when does
-Braking slower or shifting into neutral seems to have some positive effect (keep from stalling)
-Sounds like a hose issue I know, but meticulously checked.

Thoughts?

Have you tried cleaning your MAF?

Also check out your TPS. (Throttle Position Sensor) There is a write up here in the tech info for testing it.



You may also have a slow responding IAC (Idle Air Control Valve) some may tell you to try to clean this but really the only fix for this sensor is to replace it.

Check for a vacuum leak at the EGR tube.

I did clean the MAF with no help. Ill check the TPS and for a leak at the EGR tomorrow when I get home.

Thoughts on possibly a coil? Ill be checking those too.