Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

Reply
 
LinkBack Thread Tools Display Modes
Old 05-05-2013, 01:38 PM   #1
Registered User
 
Join Date: Apr 2011
Location: Quebec
Posts: 202
What is happening over 4000rpm?

What is happening in our engine over 4000rpm? I'm asking because I have an intermittent problem that I cannot find. When I push a little the engine, I often but not all the time have the engine cuting. I lift the gaz and its ok, run fine. It feels like ignition cutoff. I have change twice the MAF and twice the AOS, but still the same. I have no CEL code, and engine idle smooth and run smooth under 4000rpm. But over, it sometime cutoff, sometime not.

I know the variocam are activated at about 4000rpm, could it be related? How does it work? Could it be something else? Any idea or suggestion?

Model is a 2000 S

Thanks
Chris
wawa is offline   Reply With Quote
Old 05-05-2013, 02:17 PM   #2
Certified Boxster Addict
 
Join Date: Nov 2010
Location: Los Angeles
Posts: 7,470
Your car has the original Variocam which works via a solenoid which changes the tension on the timing chain to alter the valve timing to give more power at high RPM. As such, it is either on or off based on a pre-set RPM controlled by the DME.

Your problem could be Variocam related but high RPM drivability can also be fuel related (fuel filter, fuel pump, or injectors not flowing enough fuel at high RPM).
__________________
1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor
thstone is offline   Reply With Quote
Old 05-05-2013, 02:38 PM   #3
Registered User
 
Join Date: Apr 2011
Location: Quebec
Posts: 202
Fuel filter is change, air filter too and also spark plugs. I put injecter cleaner in last time I fuel up.
Would bad injectors or fuel pump cause a sudden cut of power? It really feel like I'm hitting a fuel cut at high RPM like some car have.

Thanks
Chris
wawa is offline   Reply With Quote
Old 05-05-2013, 08:02 PM   #4
Registered User
 
Bmod986's Avatar
 
Join Date: Nov 2011
Location: North NJ
Posts: 269
Check the coil packs because if they are cracked then your not receiving the proper sparks at the right time. So this could cause this cutoff sensation. I know that for me, my power stopped at 5,000 until I changed one of my badly cracked coil packs and now she runs good. I suggest giving that a shot.
Bmod986 is offline   Reply With Quote
Old 05-06-2013, 03:51 AM   #5
Registered User
 
Join Date: Apr 2008
Location: Southern New jersey
Posts: 1,054
Just a thought, does your car have PSM? Does it do this in all gears?
stephen wilson is offline   Reply With Quote
Old 05-06-2013, 04:03 AM   #6
Registered User
 
Join Date: Apr 2011
Location: Quebec
Posts: 202
Yes it have PSM but it does not feel like it. You think it could have something to do with it? It's random but I have experience it in 2-3-4 for sure.

Thanks
Chris
wawa is offline   Reply With Quote
Old 05-06-2013, 04:29 AM   #7
Registered User
 
Join Date: Apr 2008
Location: Southern New jersey
Posts: 1,054
Well, it doesn't seem likely in 3rd and 4th gear. I had a problem with my PSM kicking in when I increased the air pressure in my non-stock (wider & taller ) front tires .
stephen wilson is offline   Reply With Quote
Old 05-06-2013, 06:52 PM   #8
Registered User
 
Jager's Avatar
 
Join Date: Jul 2010
Location: California
Posts: 1,813
Garage
Have you checked the fuel pressure? Fuel pump might be going out.
__________________
Jäger

300K Mile Club
Jager is offline   Reply With Quote
Old 05-07-2013, 04:50 AM   #9
Registered User
 
Join Date: Apr 2011
Location: Quebec
Posts: 202
That is where I'm heading now. Fuel pump is my next target cause last night the boxster was missing in all gear and at idle. Had a hard time getting back home. Stall a couple time. Start and die seconds later. Sound more and more like fuel pump.

Now, the fuel tank is full and I'm scared to go for a ride to brun fuel. Will have to fine à big container.

Later all
Chris
wawa is offline   Reply With Quote
Old 05-07-2013, 06:49 AM   #10
Homeboy981
 
Homeboy981's Avatar
 
Join Date: Jan 2012
Location: Sherman, TX
Posts: 663
Garage
KennyBoxster had the same problem due to MAF being a "newer" model than what our ECM expected. There is an upgrade to the software, or you can run an older MAF unit.

It took KB 3 MAFs and hours to figure out. There is a report out on it…Kenny transcribed it from German! Now that's devotion to fixing a problem!

Another problem was 2nd gear shifting, slight pause or engine cutout right after shifting. All due to the wrong MAF, or too new for the car to read correctly ALL the time.

We drove around for hours, and it was only intermittent at best. We even unplugged the MAF (do NOT personally recommend that) and it RAN BETTER!

Good luck!
__________________
2002 Porsche Boxtser S - Silver & Chrome - Died from IMS failure AFTER IMS was replaced!
Homeboy981 is offline   Reply With Quote
Old 05-07-2013, 05:06 PM   #11
Registered User
 
Jager's Avatar
 
Join Date: Jul 2010
Location: California
Posts: 1,813
Garage
Quote:
Originally Posted by wawa View Post
That is where I'm heading now. Fuel pump is my next target cause last night the boxster was missing in all gear and at idle. Had a hard time getting back home. Stall a couple time. Start and die seconds later. Sound more and more like fuel pump.

Now, the fuel tank is full and I'm scared to go for a ride to brun fuel. Will have to fine à big container.

Later all
Chris
Bad fuel pump will not necessarily throw a CEL. You now have the same symptoms that I had a few years ago... Bad fuel pump.
__________________
Jäger

300K Mile Club
Jager is offline   Reply With Quote
Old 05-07-2013, 06:48 PM   #12
Moderator
 
Join Date: Feb 2012
Location: DFW
Posts: 782
Garage
Unplug the maf, undo the battery and drive the car around for 10 miles. If it improves, you may have the wrong version of the MAF. The TSB for 2000 year Boxsters can seem ambiguous and conflicting regarding MAFS. PM me if unplugging the MAF improves your situation so I can try and help you find the right version.
Kenny Boxster is offline   Reply With Quote
Old 05-08-2013, 04:51 AM   #13
Registered User
 
Join Date: Apr 2011
Location: Quebec
Posts: 202
Homeboy981 & Kenny boxster, your puting more doubt in my head now. The fuel pump is already order so I will change it anyway. But could you double check if I got the right MAF from pelican parts?

On the box it's says:
986-606-125-01-M14. 2000 from chassis 986YS62041 through 2004, or chassis 980YU625100 through 2004. Boxster S

My serial number is: xxxxx2988YU660299
2000 boxster S

Thanks
Chris
wawa is offline   Reply With Quote
Old 05-09-2013, 06:02 PM   #14
Registered User
 
Jager's Avatar
 
Join Date: Jul 2010
Location: California
Posts: 1,813
Garage
Did you measure the fuel pressure?
__________________
Jäger

300K Mile Club
Jager is offline   Reply With Quote
Old 05-10-2013, 01:49 AM   #15
Registered User
 
smagerstein's Avatar
 
Join Date: Oct 2006
Location: Slovenia
Posts: 161
Hi, I had the same problem last week and apparently it was fixed when they replaced the 'Magnetventil'. (car still with them having some other work done at the same time)

It threw a flashing CEL.

This is what they call it in german, dont know what its called in english. Price was 240€ for the part at the dealer.

Picture of problem part below.
Attached Images
 
__________________
Steven Magerstein
2002 Boxster 2.7 Seal Grey
2008 MB C200k

Past Cars
2006 MB C180k
2005 Peugeot 306
1980 928
2004 Subaru Liberty GT
2000 Nissan Pulsar SSS
smagerstein is offline   Reply With Quote
Old 05-10-2013, 05:19 AM   #16
Registered User
 
Join Date: Apr 2011
Location: Quebec
Posts: 202
That is the impulse sender. How could it be part of my problem?

I have not check fuel pressure. I dont have what it needed for it.

Later
Chris
wawa is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 10:45 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page