Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Engine rhythmically cutting out

Recommended Posts

I have a '97 Boxster, with the base engine & 5 speed transmission. I have done several things to it in the past year attempting to fix missing/rough running issues; replaced the plugs, all the coil packs, MAF sensor, and the 2 front O2 sensors. Ran great for a few days this last time (one of the new coil packs went bad; reinstalled one of the old ones that I was pretty certain was still good and reset the ECU by disconnecting the battery).

Now it has started doing something completely different; it has never done this before.... you can hold the RPM's at a steady 2k for instance, and the engine will rhythmically cut out for just a moment, just as if you had turned the engine off and then back on.... on, off, on, off, on, off and so on. The dash stays the same however, other than the RPM gauge following the revs. It started doing this for a few minutes (embarrassing when driving thru town), then stop, and then do it again the next day and stop, but now the issue seems here to stay. So far it hasn’t thrown a CEL.

I sure would love to be able to drive it and enjoy being topless before the snow flies... any ideas?

Link to comment
Share on other sites

I have no idea when the fuel filter was changed, I just bought it nearly 2 years ago now, I guess. That is something I oughta do, anyway. It's so rhythmic that I can't really see it being a fuel filter, but could be the fuel pump going on/off I guess. It may be the crank sensor … but I’m worried it may be the ECU doing it, since it is so well timed & repeated. It may be turning the coil pack feeds off, turning off the fuel injectors or any number of things… either by itself or as a result of a faulty input.

It will be fun to track down. Maybe it’s a good excuse to buy a Durametric analyzer?...lol

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.