Parts Catalog Accessories Catalog Tech Info Tech Forums
 
  Search our site:    
 Cart  | Project List | Order Status | Help    
  We salute a legendary member of the community.
Thank you for selflessly sharing your wisdom with us...
Go Back   Pelican Parts Technical BBS > 1- Porsche Technical Forums > Porsche 911 Technical Forum

Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Apr 2013
Posts: 18
Intermittent Skipping / Choking

Guys - I'm loving my new 89 911 but getting a little frustrated with some small issues.

Once the engine is warmed up, the car will choke or skip, almost like I've hit a wall or a giant pothole. I've noticed it happens most often around 3k rpm when driving a consistent speed. On an hour drive on the highway it happened 3-4 times.

I took the car in a few weeks ago and my mechanic changed out all the wires as well as the distributor cap / rotor. The problem has either stayed the same or gotten a little worst since then.


I know I owe you guys some pictures - i promise to post on 8/10 after i give it a good detail. I'm not great with a wrench but I kill it with a buffer!
Old 07-30-2013, 04:49 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #1 (permalink)
Registered User
 
Discseven's Avatar
 
Join Date: Oct 2012
Location: Miami
Posts: 822
Garage
When's the last time the fuel filter was changed RG?

(LOL on the buffer!)
__________________
Karl ~

Current: '80 Targa w /'85 3.2
Prior: '74 Carrera. '79 Silver Turbo. '79 Black Turbo.
Old 07-30-2013, 11:47 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #2 (permalink)
Registered User
 
Roger 911's Avatar
 
Join Date: Dec 2002
Location: Chicago
Posts: 642
Garage
Could be a lot of things. How's your idle, steady, or does it fluctuate? Does it only happen at 3K, or do you get some sputtering poor drivability at other (lower) engine speeds?

I was getting some low engine speed issues with my 84 motor. It turned out to be an overly lean mixture. I adjusted this (for free) and it made a huge improvement.

This thread explains the procedure;

Idle Hunting -- The problem continues!!

But again, your problem could be different, and it may not be something your comfortable tinkering with.

Roger
__________________
'72 911 3.2
'86 951
'04 VW Phaeton
'07 Audi Q7
Old 07-30-2013, 12:12 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Apr 2003
Location: Gainesville FL
Posts: 951
Garage
Here's a very simple test - when it skips, does the Tach drop rapidly? If so, it could be traced to either the speed/reference sensors or the DME relay, or the DME itself. If it doesn't drop, then I'd suspect something else, perhaps the common groove worn in the air flow meter sensor.

HTH,
Chuck.H
'89 TurboLookTarga, 361k miles
Old 07-30-2013, 12:18 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Apr 2013
Posts: 18
Thanks for the responses guys -

Car is perfect otherwise, no Idle hunting and no poor driveablity at low speed at all!

I don't notice that the tach drops rapidly - after reading previous threads I had been watching for this. To describe the issue differently, its as if i jabbed the brakes quickly and then went right back to the gas.

I will go through the records tonight and find out when the fuel filter was last changed.

Perhaps starting with the Air Flow meter sensor is the best bet?
Old 07-30-2013, 02:23 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #5 (permalink)
Registered User
 
Roger 911's Avatar
 
Join Date: Dec 2002
Location: Chicago
Posts: 642
Garage
There is some interesting info on this forum regarding cracked solder joints on the DME circuit boards. My be worth reading.

Good luck.

Roger
__________________
'72 911 3.2
'86 951
'04 VW Phaeton
'07 Audi Q7
Old 07-30-2013, 02:48 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #6 (permalink)
 
Now Available for Ordering:   101 Projects For Your BMW 3 Series 1982-2000  [more info]
Registered User
 
Join Date: Apr 2013
Posts: 18
Fuel filter was changed in March right before i bought it. I'll do some reading on the solder joints on the DME today! Thanks again
Old 07-31-2013, 03:17 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Apr 2003
Location: Gainesville FL
Posts: 951
Garage
The most common crack is on the coil transistor, the disc shaped one that stands up on the board and is attached to the heat sink.

BTW, I have found a new method to search for cracked solder joints that has worked for me - take high resolution photos of the circuit board (using a tripod or stand for stability) and blow the images up on your computer screen.

Chuck.H
'89 TurboLookTarga, 361k miles
Old 07-31-2013, 04:02 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #8 (permalink)
Old 07-31-2013, 04:02 AM
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 07:43 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 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.