 Cylinder Head Temperature Sensor, Disconnect Scenario? |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
  |
| JawjaPorsche |
 Nov 12 2018, 04:05 PM
Post
#1
|
|
Advanced Member  Group: Members Posts: 3,463 Joined: 23-July 11 From: Clayton, Georgia Member No.: 13,351 Region Association: South East States  |
My 73 1.7 FI engine starts normally. The AAR works great then my engine really runs rough until the engine warms up: usually three miles of driving. Especially bad in cold weather. A friend who also has a 914 suggested I disconnect the Cylinder Head Temperature Sensor to see if that would help and maybe isolate the problem.
Was wondering what to expect if I disconnect it. Needless to say, your input would be greatly appreciated. Thank you in advance. |
   |
 
|
| BeatNavy |
Nov 12 2018, 04:21 PM
Post
#2
|
|
Certified Professional Scapegoat Group: Members Posts: 2,924 Joined: 26-February 14 From: Easton, MD Member No.: 17,042 Region Association: MidAtlantic Region 
|
QUOTE(JawjaPorsche @ Nov 12 2018, 06:05 PM)  My 73 1.7 FI engine starts normally. The AAR works great then my engine really runs rough until the engine warms up: usually three miles of driving. Especially bad in cold weather. A friend who also has a 914 suggested I disconnect the Cylinder Head Temperature Sensor to see if that would help and maybe isolate the problem. Was wondering what to expect if I disconnect it. Needless to say, your input would be greatly appreciated. Thank you in advance. No, your engine will flood almost immediately with CHT disconnected. It may not even start. He's probably talking about (or may be thinking about) disconnecting the T1 (ambient air sensor). Disconnecting that will richen the mixture a little through the whole warm-up range. That's probably a useful test, but it's not a great long term fix. Better option is to get a CHT spacer from 914LTD. That will slow down the CHT warm up and give you a richer mixture longer while your engine warms up. |
|
|
|
| JawjaPorsche |
Nov 12 2018, 04:31 PM
Post
#3
|
|
Advanced Member Group: Members Posts: 3,463 Joined: 23-July 11 From: Clayton, Georgia Member No.: 13,351 Region Association: South East States |
QUOTE(BeatNavy @ Nov 12 2018, 06:21 PM) QUOTE(JawjaPorsche @ Nov 12 2018, 06:05 PM) My 73 1.7 FI engine starts normally. The AAR works great then my engine really runs rough until the engine warms up: usually three miles of driving. Especially bad in cold weather. A friend who also has a 914 suggested I disconnect the Cylinder Head Temperature Sensor to see if that would help and maybe isolate the problem. Was wondering what to expect if I disconnect it. Needless to say, your input would be greatly appreciated. Thank you in advance. No, your engine will flood almost immediately with CHT disconnected. It may not even start. He's probably talking about (or may be thinking about) disconnecting the T1 (ambient air sensor). Disconnecting that will richen the mixture a little through the whole warm-up range. That's probably a useful test, but it's not a great long term fix. Better option is to get a CHT spacer from 914LTD. That will slow down the CHT warm up and give you a richer mixture longer while your engine warms up. What a cool idea! I will check out the CHT spacer! Thanks! |
|
|
|
| TheCabinetmaker |
Nov 12 2018, 07:06 PM
Post
#4
|
|
I drive my car everyday Group: Members Posts: 8,300 Joined: 8-May 03 From: Tulsa, Ok. Member No.: 666 |
It won't run with it disconnected. Sounds more like an aar symptom.
|
|
|
|
| pilothyer |
Nov 12 2018, 08:47 PM
Post
#5
|
|
Member Group: Members Posts: 838 Joined: 21-May 08 From: N. Alabama Member No.: 9,080 Region Association: South East States |
QUOTE(TheCabinetmaker @ Nov 12 2018, 07:06 PM) It won't run with it disconnected. Sounds more like an aar symptom. |
|
|
|
| JawjaPorsche |
Nov 13 2018, 04:08 AM
Post
#6
|
|
Advanced Member Group: Members Posts: 3,463 Joined: 23-July 11 From: Clayton, Georgia Member No.: 13,351 Region Association: South East States |
QUOTE(TheCabinetmaker @ Nov 12 2018, 09:06 PM) It won't run with it disconnected. Sounds more like an aar symptom. I have an extra AAR so I will swap it out to see if that helps. Thank you for your input. |
|
|
|
| jim_hoyland |
Nov 13 2018, 06:55 PM
Post
#7
|
|
Get that VIN ? Group: Members Posts: 9,260 Joined: 1-May 03 From: Sunset Beach, CA Member No.: 643 Region Association: Southern California
|
The AAR is easily bench tested... (IMG:style_emoticons/default/smile.gif)
|
|
|
|
| Jamie |
Nov 13 2018, 07:23 PM
Post
#8
|
|
Senior Member Group: Members Posts: 1,025 Joined: 13-October 04 From: Georgetown,KY Member No.: 2,939 Region Association: South East States
|
QUOTE(jim_hoyland @ Nov 13 2018, 04:55 PM) Testing by what method Jim? I suspect this part might be a factor in my continuing idle searching problem. (IMG:style_emoticons/default/confused24.gif) |
|
|
|
| jim_hoyland |
Nov 14 2018, 06:45 AM
Post
#9
|
|
Get that VIN ? Group: Members Posts: 9,260 Joined: 1-May 03 From: Sunset Beach, CA Member No.: 643 Region Association: Southern California
|
QUOTE(Jamie @ Nov 13 2018, 05:23 PM) QUOTE(jim_hoyland @ Nov 13 2018, 04:55 PM) Testing by what method Jim? I suspect this part might be a factor in my continuing idle searching problem. (IMG:style_emoticons/default/confused24.gif) Remove the AAR from the car. At ambient temp, or lower, the orifice will be open or partially open; the window shade inside is the moving part that regulates the air flow. Then attach a 12 volt source to the AAR's spade connectors, and note the time. A working AAR's window shade ( inside the AAR ) will being to close. Mine closes in 1 1/2 minutes. Thats it. |
|
|
|
|
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 25th April 2024 - 03:01 AM |
Invision Power Board
v9.1.4 © 2024 IPS, Inc.