Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Technical BBS > 1- Porsche Technical Forums > 911 / 930 Turbo & Super Charging Forum

Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Jul 2009
Posts: 98
89 911 turbo Loosing power at 100mph

Hi guys ,

After replacing both fuel pumps , fuel pump relay , overboost switch & the yellow relay , i experienced another problem . The car can accelerate fast and freely revs until redline , but it seems its loosing power when it hits 100 MPH at 5th gear the car feels its loosing boost or fuel . It looses speed w/o shutting down . I try to regain speed by down shifting to second gear and it accelerate's hard from gears 2nd to 4th gear . But when it reaches 100 mph at 5th gear the problem arises again .

Thanks in advance,

Tdh888
Old 10-30-2017, 07:04 AM
  Pelican Parts Technical Article Directory    Reply With Quote #1 (permalink)
Registered User
 
T77911S's Avatar
 
Join Date: Oct 2006
Location: MYR S.C.
Posts: 8,818
squeeze the rubber elbow from the AFM to the down pipe. if it is soft it is collapsing and restricting air flow. they are not that expensive.
it may be that yours is just starting to go.
when they are really bad it cuts out in lower gears once on boost.
__________________
86 930 42kmiles [__] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD
88 BMW 325is 200K+ [__] RUNNING: [__] NOT RUNNING:
05 BMW 330CI 130K:: [__] RUNNING: [__] NOT RUNNING:
08 VOLVO V70 190K:: [__] RUNNING: [__] NOT RUNNING:
90 B2200[] RUNNING:[_] NOT RUNNING:__2000 MER E320 WAGON [_] WRECKED:[]RUNNING:
Old 10-30-2017, 07:13 AM
  Pelican Parts Technical Article Directory    Reply With Quote #2 (permalink)
Registered User
 
Join Date: Mar 2012
Location: NC
Posts: 1,157
Does it exhibit the same issues in 4th gear at say, 80mph?
__________________
Cheers,
Patrick
'78 930 #441
'87 951
Old 10-30-2017, 11:03 AM
  Pelican Parts Technical Article Directory    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Jul 2009
Posts: 98
Hi guys ,

Thank you very much for your reply . Patina it does not happen at 4th gear at 80MPH . T77911S if its not much of trouble pls post a picture of the specific rubber elbow from the down pipe . The car does not loose boost at lower gear it accelerates like a scalded cat .
Anymore suggestions/ comments from other fellow members .

Thanks in advance.

Tdh888
Old 10-30-2017, 12:33 PM
  Pelican Parts Technical Article Directory    Reply With Quote #4 (permalink)
Registered User
 
Jeff NJ's Avatar
 
Join Date: Nov 2013
Location: NW NJ
Posts: 1,083
Do you have an AFR gauge or boost gauge that works well? (many stock ones are iffy)

if so, what do those numbers show?
__________________
1988 930 Venetian Blue
Old 10-30-2017, 12:37 PM
  Pelican Parts Technical Article Directory    Reply With Quote #5 (permalink)
Registered User
 
Ken911's Avatar
 
Join Date: May 2005
Location: Loxahatchee, florida
Posts: 2,480
Sounds like you need to measure the fuel flow. There are steps in the manual for that. You could either have a bad pump, clogged filter, or clogged fuel tank strainer. The other problem with loosing fuel at peak load could be detonation and all the subsequent issues with that. If it's a boost leak check the recirc valve that plugs into the same elbow meantioned above. It's plasic and somewhat unreliable. most people replace them with a billet version.
__________________
88 turbo Guards red Targa slant nose, and yes I am a horsepower junkie, 3.4liter,7.5 to 1 JE pistons, Adjustable WUR, Imagine fuel head, 1 bar waste gate headers,allthe cis toys. Now apart to become the next EFI monster. fabbing my own intake, headers Individual throttle bodies, MS-3, pauter rods, Xtreme twin plugged heads, gt-2 evo cams cop's.
05 Cayenne S lapis blue
Old 10-30-2017, 12:42 PM
  Pelican Parts Technical Article Directory    Reply With Quote #6 (permalink)
Registered User
 
Join Date: Jul 2009
Posts: 98
Hi ,

Sorry I dont have an AFR gauge or another boost gauge Jeff , will try to look for one. Ken911 i have a new fuel filter , both fuel pumps are brandnew as well . Hi Ken if its not that much trouble can you post a picture of the recirc valve that plugs in to the elbow .
By the way my car is bone stock .

Thanks in advance,

Tdh888
Old 10-30-2017, 12:51 PM
  Pelican Parts Technical Article Directory    Reply With Quote #7 (permalink)
Registered User
 
Ken911's Avatar
 
Join Date: May 2005
Location: Loxahatchee, florida
Posts: 2,480
I dont have a pic of that your car is a 964 turbo which is set up differently than mine. If you look at the rubber elbow that goes from the air flow meter. It has a little black plastic valve with a vacuum line attached. I believe thats the one.
__________________
88 turbo Guards red Targa slant nose, and yes I am a horsepower junkie, 3.4liter,7.5 to 1 JE pistons, Adjustable WUR, Imagine fuel head, 1 bar waste gate headers,allthe cis toys. Now apart to become the next EFI monster. fabbing my own intake, headers Individual throttle bodies, MS-3, pauter rods, Xtreme twin plugged heads, gt-2 evo cams cop's.
05 Cayenne S lapis blue
Old 10-30-2017, 12:56 PM
  Pelican Parts Technical Article Directory    Reply With Quote #8 (permalink)
Registered User
 
Join Date: Mar 2012
Location: NC
Posts: 1,157
Quote:
Originally Posted by Ken911 View Post
I dont have a pic of that your car is a 964 turbo which is set up differently than mine. If you look at the rubber elbow that goes from the air flow meter. It has a little black plastic valve with a vacuum line attached. I believe thats the one.
89 is not a 964.
__________________
Cheers,
Patrick
'78 930 #441
'87 951
Old 10-30-2017, 01:02 PM
  Pelican Parts Technical Article Directory    Reply With Quote #9 (permalink)
Registered User
 
Ken911's Avatar
 
Join Date: May 2005
Location: Loxahatchee, florida
Posts: 2,480
Quote:
Originally Posted by patina View Post
89 is not a 964.
Oh ok I thought that's when they changed to the different recirc valve.
Old 10-30-2017, 02:24 PM
  Pelican Parts Technical Article Directory    Reply With Quote #10 (permalink)
Registered User
 
Ken911's Avatar
 
Join Date: May 2005
Location: Loxahatchee, florida
Posts: 2,480
Quote:
Originally Posted by patina View Post
89 is not a 964.
Oh ok I thought that's when they changed to the different recirc valve.
Old 10-30-2017, 02:31 PM
  Pelican Parts Technical Article Directory    Reply With Quote #11 (permalink)
Registered User
 
Join Date: Jul 2009
Posts: 98
Quote:
Originally Posted by Ken911 View Post
Oh ok I thought that's when they changed to the different recirc valve.
Hi Ken , Patina

Patina , Ken is right . Thanks for the picture Ken , may I ask were the recirculating valve is in the picture ?

Thanks in advance ,

Tdh888
Old 10-30-2017, 03:31 PM
  Pelican Parts Technical Article Directory    Reply With Quote #12 (permalink)
 
Now Available for Ordering:   101 Projects For Your BMW 3 Series 1982-2000  [more info]
Registered User
 
Ken911's Avatar
 
Join Date: May 2005
Location: Loxahatchee, florida
Posts: 2,480
ok sorry for the sideways picture for some reason when they get posted from my phone they come out that way. on a 930 the recirc valve is that large magnesium block with the blue rag in it. Whick shouldnt be a problem since your car is not a 964. the elbow in question is in the lower left of the picture coning from the AFM to the recirc valve.
__________________
88 turbo Guards red Targa slant nose, and yes I am a horsepower junkie, 3.4liter,7.5 to 1 JE pistons, Adjustable WUR, Imagine fuel head, 1 bar waste gate headers,allthe cis toys. Now apart to become the next EFI monster. fabbing my own intake, headers Individual throttle bodies, MS-3, pauter rods, Xtreme twin plugged heads, gt-2 evo cams cop's.
05 Cayenne S lapis blue
Old 10-31-2017, 07:08 AM
  Pelican Parts Technical Article Directory    Reply With Quote #13 (permalink)
Registered User
 
somoney311's Avatar
 
Join Date: Jun 2013
Location: Beaufort, SC
Posts: 89
Garage
pictures...worth a thousand words


The red circle is the elbow they are talking about the white circle is the recirculating valve.
__________________
James
1989 Slate Grey 930...still tinkering
Old 10-31-2017, 07:51 AM
  Pelican Parts Technical Article Directory    Reply With Quote #14 (permalink)
Registered User
 
Join Date: Oct 2003
Location: Central Fla
Posts: 1,379
Have you looked at the intake manifold to intake port nuts, they will loosen up.
Mike Bruns
__________________
The two most useless things to a driver are the braking distance behind you and nine-tenths of a second ago.
Old 10-31-2017, 08:30 AM
  Pelican Parts Technical Article Directory    Reply With Quote #15 (permalink)
Registered User
 
T77911S's Avatar
 
Join Date: Oct 2006
Location: MYR S.C.
Posts: 8,818
the one in red above.
just make sure its not soft before you start down other roads.

just thinking with the longer pull in 5th that it may have enough time to collapse. lower gears on boost time is shorter and it may not be soft enough to collapse.

fuel flow would be next on my list. flow more so than pressure. needs to be checked at the return side or out of the FD.
1500cc/ 30 sec I do believe
__________________
86 930 42kmiles [__] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD
88 BMW 325is 200K+ [__] RUNNING: [__] NOT RUNNING:
05 BMW 330CI 130K:: [__] RUNNING: [__] NOT RUNNING:
08 VOLVO V70 190K:: [__] RUNNING: [__] NOT RUNNING:
90 B2200[] RUNNING:[_] NOT RUNNING:__2000 MER E320 WAGON [_] WRECKED:[]RUNNING:
Old 10-31-2017, 09:29 AM
  Pelican Parts Technical Article Directory    Reply With Quote #16 (permalink)
Registered User
 
Join Date: Jul 2009
Posts: 98
Thank you guys for the replies and comments , will just update you to what the mechanic found out .

Best regard ,

Luigi
Old 11-01-2017, 02:21 PM
  Pelican Parts Technical Article Directory    Reply With Quote #17 (permalink)
Registered User
 
Join Date: Jul 2009
Posts: 98
Quote:
Originally Posted by T77911S View Post
the one in red above.
just make sure its not soft before you start down other roads.

just thinking with the longer pull in 5th that it may have enough time to collapse. lower gears on boost time is shorter and it may not be soft enough to collapse.

fuel flow would be next on my list. flow more so than pressure. needs to be checked at the return side or out of the FD.
1500cc/ 30 sec I do believe
Hi guys ,

How can you say if the elbow is hard or soft . Is it normal if one can pinch it or if itís new you canít pinch it .
I checked the elbow of my car and you can pinch it specially at the angle of the bend .

Thanks in advance ,

Luigi
Old 11-03-2017, 06:07 AM
  Pelican Parts Technical Article Directory    Reply With Quote #18 (permalink)
Registered User
 
Ken911's Avatar
 
Join Date: May 2005
Location: Loxahatchee, florida
Posts: 2,480
It should be pretty stiff
Old 11-04-2017, 07:42 AM
  Pelican Parts Technical Article Directory    Reply With Quote #19 (permalink)
Registered User
 
T77911S's Avatar
 
Join Date: Oct 2006
Location: MYR S.C.
Posts: 8,818
Mine is a few years old and I can squeeze it but I can't squeeze it closed with one hand.
__________________
86 930 42kmiles [__] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD
88 BMW 325is 200K+ [__] RUNNING: [__] NOT RUNNING:
05 BMW 330CI 130K:: [__] RUNNING: [__] NOT RUNNING:
08 VOLVO V70 190K:: [__] RUNNING: [__] NOT RUNNING:
90 B2200[] RUNNING:[_] NOT RUNNING:__2000 MER E320 WAGON [_] WRECKED:[]RUNNING:
Old 11-04-2017, 01:19 PM
  Pelican Parts Technical Article Directory    Reply With Quote #20 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 01:38 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2016 Pelican Parts - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.