Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

Idle surge after Plug Change

Thread Tools
 
Search this Thread
 
Old Oct 21, 2004 | 05:47 PM
  #1  
dave1200's Avatar
dave1200
Thread Starter
Pro
 
Joined: May 2004
Posts: 581
Likes: 0
From: Charlotte
Default Idle surge after Plug Change

Hi all. I have a strange question.
On the 88 32 Valve engine. It had a slight idle surge after it got to temp, not bad, but hunting a little. I put new plugs in, and it started surging very fast up down up down. Sounded like someone was in the car reving it. I triple checked all the vaccume connections to make sure I didnt knock something off.

Thats the only change I made:
The plugs I removed were all carboned up.

Why would it do this just because of a plug change? It didnt do it while it was in gear. only Park or Neutral. The car was ALOT morte responsive with the new plugs

Thanks for any insight to this strange problem.

Dave
Reply
Old Oct 21, 2004 | 05:55 PM
  #2  
Gretch's Avatar
Gretch
Range Master
Pepsie Lite
Lifetime Rennlist
Member
 
Joined: Apr 2002
Posts: 54,283
Likes: 1,236
Default

You have either a vacuum leak or your idle stabilizer is gummed up. Prolly the idle stabilizer. Do a search on it and give it the WD40 treatment......
Reply
Old Oct 21, 2004 | 05:59 PM
  #3  
whall's Avatar
whall
Pro
 
Joined: Jul 2004
Posts: 743
Likes: 0
Default

Dave,

I had the exact same thing happen to me. I asked here and was told to check vacuum. Bought a vacuum tester, found the leak way under the back, replaced the hoses and fixed the problem.
Reply
Old Oct 21, 2004 | 05:59 PM
  #4  
dave1200's Avatar
dave1200
Thread Starter
Pro
 
Joined: May 2004
Posts: 581
Likes: 0
From: Charlotte
Default

where exactly is teh idel stabilizer on these cars? WHat does it look like? What general location would it be?
Reply
Old Oct 21, 2004 | 06:04 PM
  #5  
marton's Avatar
marton
Drifting
 
Joined: Nov 2001
Posts: 2,233
Likes: 1
From: zürich, switzerland
Default

take a carefull look at any vacuum lines near theactual plugs, maybe one got knocked off during the plug change?
Reply
Old Oct 21, 2004 | 06:08 PM
  #6  
Gretch's Avatar
Gretch
Range Master
Pepsie Lite
Lifetime Rennlist
Member
 
Joined: Apr 2002
Posts: 54,283
Likes: 1,236
Default

here is a picture. it is under the intake manifold. DO A SEARCH.
Reply
Old Oct 21, 2004 | 06:10 PM
  #7  
dave1200's Avatar
dave1200
Thread Starter
Pro
 
Joined: May 2004
Posts: 581
Likes: 0
From: Charlotte
Default

Thanks...got it!!!
Reply
Old Oct 21, 2004 | 08:56 PM
  #8  
dave1200's Avatar
dave1200
Thread Starter
Pro
 
Joined: May 2004
Posts: 581
Likes: 0
From: Charlotte
Default

I put the old plugs back in..no more surge. The new ones were NGK's ????
Very strange.....
Reply
Rennlist Stories

The Best Porsche Posts for Porsche Enthusiasts

story-0

9 Vehicles Porsche Helped Engineer that Aren't Porsches

 Verdad Gallardo
story-1

9 Features and Characteristics That Only Porsche People Understand

 Verdad Gallardo
story-2

I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

 Joe Kucinski
story-3

10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

 Verdad Gallardo
story-4

Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner

 Joe Kucinski
story-5

This Builder Is Turning Heads With Its Slantnose 911 Creation

 Verdad Gallardo
story-6

Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture

 Verdad Gallardo
story-7

Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look

 Verdad Gallardo
story-8

10 Porsche Colors That Have More Personality Than Most People

 Verdad Gallardo
story-9

Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod

 Verdad Gallardo
Old Oct 22, 2004 | 11:42 AM
  #9  
Gretch's Avatar
Gretch
Range Master
Pepsie Lite
Lifetime Rennlist
Member
 
Joined: Apr 2002
Posts: 54,283
Likes: 1,236
Default

I will say that is strange.................Try AC platinum plugs..................I have had great results with them. Bosch are also quite good, and actually cheaper. This is because the platinum center piece is considerably smaller......
Reply
Old Oct 22, 2004 | 11:54 AM
  #10  
Mark's Avatar
Mark
Addict
Rennlist Member

 
Joined: Jan 2003
Posts: 3,537
Likes: 1
From: Mountains of GA!
Default

Recent thread on spark plug selection - Others (like the AC's mentioned by Gretch) are ok, but general consensus - Bosch Super's (STAY AWAY FROM THE MULTI ELECTRODES!).

It could be that the NGK's are the incorrect heat range....AND - there is likely an underlying reason that the old ones were "carboned up"
Reply




All times are GMT -3. The time now is 09:13 PM.

story-0
9 Vehicles Porsche Helped Engineer that Aren't Porsches

Slideshow: Long before engineering consulting became trendy, Porsche was quietly helping other automakers build everything from supercars to economy hatchbacks.

By Verdad Gallardo | 2026-05-15 12:44:44


VIEW MORE
story-1
9 Features and Characteristics That Only Porsche People Understand

Slideshow: Some brands build cars. Porsche builds traditions, obsessions, and a few habits that stopped making sense decades ago but somehow became part of the charm.

By Verdad Gallardo | 2026-05-13 18:46:13


VIEW MORE
story-2
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

Slideshow: Six years and 500 Rennlist articles later, these are the biggest changes at Porsche.

By Joe Kucinski | 2026-05-11 09:52:55


VIEW MORE
story-3
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

Slideshow: Some Porsches exist for very specific reasons-others feel like they were built just to see if anyone would notice.

By Verdad Gallardo | 2026-05-06 18:00:32


VIEW MORE
story-4
Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner

Slideshow: Choosing between the 911 GT3 S/C and 718 Spyder RS in 10 key categories to determine one surprising winner.

By Joe Kucinski | 2026-05-05 12:51:46


VIEW MORE
story-5
This Builder Is Turning Heads With Its Slantnose 911 Creation

Slideshow: A small Polish tuner has reimagined the Porsche 911 Slantnose for the modern era, blending 1980s nostalgia with widebody tuning culture and serious performance upgrades.

By Verdad Gallardo | 2026-05-01 10:49:43


VIEW MORE
story-6
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture

Slideshow: Porsche has created a Japan-only 911 GT3 Artisan Edition that blends track-ready hardware with design cues inspired by traditional Japanese craftsmanship.

By Verdad Gallardo | 2026-04-28 19:37:40


VIEW MORE
story-7
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look

Slideshow: Porsche's latest electric Cayenne Coupe blends dramatic styling with supercar acceleration, turning the brand's midsize SUV into a 1,139-horsepower flagship.

By Verdad Gallardo | 2026-04-27 19:39:30


VIEW MORE
story-8
10 Porsche Colors That Have More Personality Than Most People

Slideshow: Porsche's wildest paint colors aren't just shades-they're full-blown personalities on four wheels.

By Verdad Gallardo | 2026-04-27 19:38:13


VIEW MORE
story-9
Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod

Slideshow: The last of the Speedsters doesn't just close a chapter, it makes quite the bold, air-cooled statement.

By Verdad Gallardo | 2026-04-22 17:55:04


VIEW MORE