2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

S5 Tii Fuel Cut Hackjob and weird decel issue

Thread Tools
 
Search this Thread
 
Old 12-22-14, 03:34 PM
  #51  
Rotary Enthusiast

Thread Starter
iTrader: (5)
 
djSL's Avatar
 
Join Date: Feb 2012
Location: Vancouver, WA
Posts: 1,047
Received 71 Likes on 49 Posts
The old tps wouldn't stay within the appropriate voltage range.

New tps still gives me a code but has the same problem to a lesser extent. Could it be the boost sensor?
Old 12-22-14, 04:06 PM
  #52  
Moderator

iTrader: (1)
 
satch's Avatar
 
Join Date: Jun 2005
Location: tulsa,ok.
Posts: 11,738
Received 12 Likes on 11 Posts
Boost sensor should not affect the idle.
Old 12-22-14, 04:11 PM
  #53  
Rotary Enthusiast

Thread Starter
iTrader: (5)
 
djSL's Avatar
 
Join Date: Feb 2012
Location: Vancouver, WA
Posts: 1,047
Received 71 Likes on 49 Posts
So then somehow, when I hit the accelerator, the tps is getting thrown off and getting different readings. It only seems to set it off under moderate throttle.
Old 12-22-14, 05:32 PM
  #54  
Rotary Enthusiast

Thread Starter
iTrader: (5)
 
djSL's Avatar
 
Join Date: Feb 2012
Location: Vancouver, WA
Posts: 1,047
Received 71 Likes on 49 Posts
Could an exhaust leak at the turbo/downpipe flange throw off the readings some how? I have a pretty bad one at the downpipe gasket.

Clearing the codes and setting the tps makes the problem go away until I touch the accelerator with moderate pressure and it trips the check engine light and the surging idle comes back in as well as the hesitation.

I may be grabbing at straws here but I have no other ideas.
Old 12-26-14, 07:34 PM
  #55  
Rotary Enthusiast

Thread Starter
iTrader: (5)
 
djSL's Avatar
 
Join Date: Feb 2012
Location: Vancouver, WA
Posts: 1,047
Received 71 Likes on 49 Posts
Figured out the 3k sticking issue. The intercooler wasn't bolted on tight enough and came loose causing a vacuum leak under pressure. Still having the same problem with the CEL and hesitation though.
Old 12-26-14, 08:16 PM
  #56  
Rotary Enthusiast

Thread Starter
iTrader: (5)
 
djSL's Avatar
 
Join Date: Feb 2012
Location: Vancouver, WA
Posts: 1,047
Received 71 Likes on 49 Posts
Late Edit:

Could it be the blitz bov running vented causing the TPS or MAF to be off?
Old 12-27-14, 09:31 PM
  #57  
Rotary Enthusiast

Thread Starter
iTrader: (5)
 
djSL's Avatar
 
Join Date: Feb 2012
Location: Vancouver, WA
Posts: 1,047
Received 71 Likes on 49 Posts
Blocked off the BOV and the car ran much better. Still a slight hesitation (nowhere near as bad) and the cel still trips under acceleration.
Old 12-28-14, 05:15 PM
  #58  
Rotary Enthusiast

Thread Starter
iTrader: (5)
 
djSL's Avatar
 
Join Date: Feb 2012
Location: Vancouver, WA
Posts: 1,047
Received 71 Likes on 49 Posts
Would the fact that the car is using a JDM engine harness be the cause of random CEL tripping? I wonder if I should just pick up a USDM harness and see if that fixes things.
Old 12-28-14, 07:51 PM
  #59  
Moderator

iTrader: (1)
 
satch's Avatar
 
Join Date: Jun 2005
Location: tulsa,ok.
Posts: 11,738
Received 12 Likes on 11 Posts
Don't believe the JDM harness is plug and play unless there were some alterations made.
Old 12-28-14, 08:38 PM
  #60  
Rotary Enthusiast

Thread Starter
iTrader: (5)
 
djSL's Avatar
 
Join Date: Feb 2012
Location: Vancouver, WA
Posts: 1,047
Received 71 Likes on 49 Posts
Well, I am unsure which harness was used. However, the issue is fixed! (mostly). As stated before, I noticed the BOV was set to vent to the atmosphere. This is typically a no no on MAF based cars, so I made a crappy plastic block off plate and the car seemed to run a little better. I then set about the task of making a recirculation adapter since BLITZ doesn't carry one for this model in the last 4 years :/

Went to Home Depot and bought a 3/4 ID piece of pipe that has a threaded end, threaded in a brass barb 3/8 to 1/2 fitting and attached a section of vacuum hose to the intake elbow.




Car idles much smoother, I just need to set the TPS one last time and lower the idle and it should be done!

I am still completely bewildered as to why the CEL keeps tripping out, but for now I am not that concerned.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
alphawolff
1st Generation Specific (1979-1985)
17
11-17-15 05:57 PM
The Shaolin
2nd Generation Specific (1986-1992)
9
09-14-15 07:50 PM
armans
3rd Generation Specific (1993-2002)
5
08-15-15 09:08 PM



Quick Reply: S5 Tii Fuel Cut Hackjob and weird decel issue



All times are GMT -5. The time now is 04:21 AM.