987 Cuts out Briefly Under Acceleration.

[darkstormvx]

Hey Guys,
2005 987 S 178,000 miles.
I'm having an issue during acceleration from stops and on the highway. This occurs at any engine temperature. Usually occurs after a stop sign or light. I will accelerate moderatly, like you would to pull into the street, and as the RPMs build and I accelerate I will lose engine power for a brief moment. Maybe 2 or 3 seconds, and then the power jumps back like nothing happened. When I lose power, the RPMs drop slightly, but never below idle, and there is a distinctive jerk every time it happens, like the power gets reversed for a second. This happens usually on main streets but also on the highway while cruising, albeit while crusing its just brief second or so. It happens more since it's colder.

It's been going on a few months and I figured it's the fuel pump, since I've been having trouble starting the car a lot for several months. It always started but took several revs. Now, I've replaced the fuel pump, and it starts like a champ, but I still get these moments of lost power. I figured the pump was the cause for both problems since cutting out is a symptom of a bad pump, but I'm not sure now. It happens after I hit sizeable bumps on the highway too.

I think it may be the fuel pump relay or throttle body needing cleaning. Ive run thru fuel system cleaner a while ago, and I lost the AOS almost a year ago, which required some cleaning and replacement if that makes a difference.

If anyone has an opinion it would be appreciated before I goto the dealership. No CELs. No weird smoke or sounds. Spark plugs mostly new, around a year and a half old. Thx.