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 Forums > Porsche Forums > Porsche 924/944/968 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
What would Darth Vader do
 
Gordon Rankin's Avatar
 
Join Date: Feb 2001
Location: Orange, California
Posts: 1,324
Send a message via Yahoo to Gordon Rankin
Missing At High Speed

My car is missing at high speed. I am not sure if it is electrical or fuel related as it only happens at higher speeds.. 65+
Ive replaced fuel filter and have run Chevron exclusively and used a bottle of Techron to no avail. Has new plugs, air filter and cap, rotor. Any ideas?
Starts to crap out at 70 and then feels (if I floor it) like one cylinder is kicking in.
__________________
1983 944 (2002 to now)
3-924's (Sold)
1967-912 (Traded)
NEVER put a used water pump in your car...
Old 06-05-2004, 07:31 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
bearone2's Avatar
 
Join Date: Jun 2003
Location: Phoenix, AZ
Posts: 1,327
don't go fast
__________________
87 951, K27/6, Almond Beige, 17" Turbotwist
87 944S, alpine white, 5sp died a violent death
84 944, silver/brown, auto, gone but not forgotten

"may the force be with you"
Old 06-05-2004, 07:45 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
SoCal Driver's Avatar
 
Join Date: Feb 2002
Location: Costa Mesa
Posts: 8,587
Garage
Need to check the sensors. Have to do the front axle on the wifes car tomorrow morning.
__________________
Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 06-05-2004, 11:02 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Mar 2004
Location: Kansas City
Posts: 45
what rpm's are you experiencing this at, and does it always occur at the same rpm's or does it vary?

Regards,
__________________
Scott Harrison
'82 928 Wife's car
'83 944 track car
'84 944 daughters car now...
'87 951 the Gen'l Sherman
'92 968 cab Garage Queen
www.kcws.org member
Old 06-06-2004, 11:34 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
What would Darth Vader do
 
Gordon Rankin's Avatar
 
Join Date: Feb 2001
Location: Orange, California
Posts: 1,324
Send a message via Yahoo to Gordon Rankin
my tach is non op. Happens when I am cruising in 5th gear
__________________
1983 944 (2002 to now)
3-924's (Sold)
1967-912 (Traded)
NEVER put a used water pump in your car...
Old 06-07-2004, 12:27 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Burn the fire.
 
Brando's Avatar
 
Join Date: May 2003
Location: Orange County, CA
Posts: 6,061
Garage
That would be... like 1800 RPMs? I'm not sure...

I believe fourth gear at 60 is 2200 RPMs... ?
__________________
[x] Working | [_] Broken: 2017 Victory Octane
[x] Working | [_] Broken: 2005 Ram 1500 SLT w/5.7L Hemi

"Drive it like you stole it."
Old 06-07-2004, 12:46 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered User
 
Join Date: Mar 2004
Location: Kansas City
Posts: 45
I'd want more details about your problem before I could make anything more than suggestions, but I'd start with the simple stuff first, make sure the plugs/wires/cap and rotor are in decent shape, and make sure that the fuel filter is fresh. You'd be amazed at how often folks (including plenty of pro shops) head straight for the most difficult, complex and expensive repairs first, before ruling out the easy stuff.

Post more details and we'll see if we can't help narrow it down for you. For what its worth, I doubt its fuel related, or I would think you'd feel it more than just at highway speeds.

Regards,
__________________
Scott Harrison
'82 928 Wife's car
'83 944 track car
'84 944 daughters car now...
'87 951 the Gen'l Sherman
'92 968 cab Garage Queen
www.kcws.org member
Old 06-07-2004, 06:28 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
SoCal Driver's Avatar
 
Join Date: Feb 2002
Location: Costa Mesa
Posts: 8,587
Garage
Broken tach. Forgot about that. Disconnect it and see if that stops the missing.
__________________
Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 06-07-2004, 10:44 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
What would Darth Vader do
 
Gordon Rankin's Avatar
 
Join Date: Feb 2001
Location: Orange, California
Posts: 1,324
Send a message via Yahoo to Gordon Rankin
Please review my original post. covered those points-


Quote:
Originally posted by sh944
I'd want more details about your problem before I could make anything more than suggestions, but I'd start with the simple stuff first, make sure the plugs/wires/cap and rotor are in decent shape, and make sure that the fuel filter is fresh. You'd be amazed at how often folks (including plenty of pro shops) head straight for the most difficult, complex and expensive repairs first, before ruling out the easy stuff.

Post more details and we'll see if we can't help narrow it down for you. For what its worth, I doubt its fuel related, or I would think you'd feel it more than just at highway speeds.

Regards,
__________________
1983 944 (2002 to now)
3-924's (Sold)
1967-912 (Traded)
NEVER put a used water pump in your car...
Old 06-07-2004, 07:44 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered User
 
SoCal Driver's Avatar
 
Join Date: Feb 2002
Location: Costa Mesa
Posts: 8,587
Garage
Yeah! Even replaced the radiator! Still misses.

Disconnect the bad tach and report back.
__________________
Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 06-07-2004, 08:38 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registered User
 
Join Date: Mar 2004
Location: Kansas City
Posts: 45
um.. oops! my bad! I don't know how I missed it...

SoCal, is it due to a function of the upshift light that you are suggesting he disconnect the tach?

Regards,
__________________
Scott Harrison
'82 928 Wife's car
'83 944 track car
'84 944 daughters car now...
'87 951 the Gen'l Sherman
'92 968 cab Garage Queen
www.kcws.org member
Old 06-07-2004, 08:51 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered User
 
SoCal Driver's Avatar
 
Join Date: Feb 2002
Location: Costa Mesa
Posts: 8,587
Garage
His tach jumps around about twice per second. All early 944 tachs connect directly to the coil wire from the DME. Bad tach could be shorting the coil wire to ground.

If Gordon's tach was working correctly I wouldn't have questioned it.
__________________
Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 06-07-2004, 09:21 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
What would Darth Vader do
 
Gordon Rankin's Avatar
 
Join Date: Feb 2001
Location: Orange, California
Posts: 1,324
Send a message via Yahoo to Gordon Rankin
Ahha!



Quote:
Originally posted by SoCal Driver
His tach jumps around about twice per second. All early 944 tachs connect directly to the coil wire from the DME. Bad tach could be shorting the coil wire to ground.

If Gordon's tach was working correctly I wouldn't have questioned it.
__________________
1983 944 (2002 to now)
3-924's (Sold)
1967-912 (Traded)
NEVER put a used water pump in your car...
Old 06-07-2004, 10:25 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
What would Darth Vader do
 
Gordon Rankin's Avatar
 
Join Date: Feb 2001
Location: Orange, California
Posts: 1,324
Send a message via Yahoo to Gordon Rankin
updated:::
Replaced tach and voila, no more missing at high speeds!!!
I dont quite understand it but for some reason the non op of my tach affected the running of my car...Strange!!
__________________
1983 944 (2002 to now)
3-924's (Sold)
1967-912 (Traded)
NEVER put a used water pump in your car...
Old 06-14-2004, 01:04 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Registered User
 
SoCal Driver's Avatar
 
Join Date: Feb 2002
Location: Costa Mesa
Posts: 8,587
Garage
Not strange. Tach and coil have same wire in common. Bad tach = bad ignition.
__________________
Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 06-14-2004, 08:49 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
Registered User
 
Join Date: Apr 2001
Location: UK
Posts: 358
once again ure da man so cal - great diags and fix - taking my hat of 2 you so cal
Old 06-14-2004, 11:15 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Registered User
 
SoCal Driver's Avatar
 
Join Date: Feb 2002
Location: Costa Mesa
Posts: 8,587
Garage
Don't applaud -- just throw money!

Actually I've been working with Gordon on this for weeks. Forgot all about the flaky tach.
__________________
Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 06-14-2004, 01:54 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #17 (permalink)
What would Darth Vader do
 
Gordon Rankin's Avatar
 
Join Date: Feb 2001
Location: Orange, California
Posts: 1,324
Send a message via Yahoo to Gordon Rankin
MANY thanks to Hugh for the help!!
__________________
1983 944 (2002 to now)
3-924's (Sold)
1967-912 (Traded)
NEVER put a used water pump in your car...
Old 06-14-2004, 05:33 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #18 (permalink)
 
Registered User
 
Don 944 LA's Avatar
 
Join Date: Nov 2003
Location: Downtown LA CA / North Texas
Posts: 1,175
Thumbs up

you da man !!!!!


now why do I miss at 4500 in 5th after accelerating rather quickly through the gears, as it hits 4500, it blogs momentarily.

I would say the speed is about 60-70. It only does it from dead stop up through gears. Also, I'm runnin 87 gas and the FQS is back to position 0.

any thoughts ??

Should I move the FQS for 87 octane ??
__________________
944 85.0 Kalahari Beige -- Dead/Gone/NotForgotten (Ran Like a Raped Banshee) 944 85.5 Guards Red
Current Stable 944 83 Kalahari Beige manual rack, short 5th gear951 86 Guards Red, pristine TurboYou must not anger the Porsche Gods - you MUST leave one small item unrepaired, lest the Stuttgartians smite thine car with bad Ju-Ju-AF Juvat
Old 06-14-2004, 08:10 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #19 (permalink)
Registered User
 
SoCal Driver's Avatar
 
Join Date: Feb 2002
Location: Costa Mesa
Posts: 8,587
Garage
Vacuum leak or air flow sensor or both. Check the large rubber duct to the throttle body.
__________________
Hugh - So Cal 83 944 Driver Person
NOT a 'real' Porsche -- Its Better!!!!
When was the last time you changed your timing and balance belts and/or cam chain and tensioner?
New Users please add your car's year and model to your signature line!
Never break more than you fix!
Old 06-14-2004, 09:37 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #20 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 11:07 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization 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
 

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