Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
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.
 

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
> Stalling at low idle when warmed up, Stalling
tsvo
post Apr 17 2019, 06:44 PM
Post #1


Member
**

Group: Members
Posts: 123
Joined: 30-January 16
From: Chicago
Member No.: 19,616
Region Association: Upper MidWest



I have a 1973, 1.7 with FI still on it. The car is stalling at idle after the engine warms up. Any ideas what to adjust or look for? Things that may be contributing, but not sure. I think there is a vaccum leak. It smells like it is running rich. I recently replaced the fuel pump.

Any help is much appreciated.

Thanks,
Terry
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
mgphoto
post Apr 17 2019, 07:09 PM
Post #2


"If there is a mistake it will find me"
***

Group: Members
Posts: 1,335
Joined: 1-April 09
From: Los Angeles, CA
Member No.: 10,225
Region Association: Southern California



QUOTE(tsvo @ Apr 17 2019, 05:44 PM) *

I have a 1973, 1.7 with FI still on it. The car is stalling at idle after the engine warms up. Any ideas what to adjust or look for? Things that may be contributing, but not sure. I think there is a vaccum leak. It smells like it is running rich. I recently replaced the fuel pump.

Any help is much appreciated.

Thanks,
Terry

Check the MPS, see if it holds vacuum and for how long.
Air leak would cause fast idle.
Check for kinked fuel line?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
tsvo
post Apr 17 2019, 07:11 PM
Post #3


Member
**

Group: Members
Posts: 123
Joined: 30-January 16
From: Chicago
Member No.: 19,616
Region Association: Upper MidWest



QUOTE(mgphoto @ Apr 17 2019, 08:09 PM) *

QUOTE(tsvo @ Apr 17 2019, 05:44 PM) *

I have a 1973, 1.7 with FI still on it. The car is stalling at idle after the engine warms up. Any ideas what to adjust or look for? Things that may be contributing, but not sure. I think there is a vaccum leak. It smells like it is running rich. I recently replaced the fuel pump.

Any help is much appreciated.

Thanks,
Terry

Check the MPS, see if it holds vacuum and for how long.
Air leak would cause fast idle.
Check for kinked fuel line?


Thank you
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Rand
post Apr 17 2019, 09:37 PM
Post #4


Cross Member
*****

Group: Members
Posts: 7,409
Joined: 8-February 05
From: OR
Member No.: 3,573
Region Association: None



(IMG:style_emoticons/default/agree.gif)
Vacuum leaks on Djet usually cause high idle. An exception is the MPS which fails to full rich if it doesn't hold a vacuum (whether via the hose or the diaphragm within).

If you pull the vacuum hose off the MPS while it's running, what changes?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
thelogo
post Apr 18 2019, 07:26 AM
Post #5


Senior Member
***

Group: Retired Members
Posts: 1,510
Joined: 6-April 10
Member No.: 11,572
Region Association: None



Once d jet stops working .
The really problem could be anywhere
And beyond guessing and hopeing
There is no way to test or identifyi the issue or soultion short of replacing or rebuilding all components that are nla

So if it still runs it is in some form of compromised
Performance aka limp mode .

I love it when something that supposed to last 10 years go's strong for 50yrs. And when it fails it fails slowly (Djet)

But

I hate it when cars or planes catch on fire
Don't ignore the warning signs
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Rand
post Apr 18 2019, 10:30 AM
Post #6


Cross Member
*****

Group: Members
Posts: 7,409
Joined: 8-February 05
From: OR
Member No.: 3,573
Region Association: None



Ignore the last post. Djet is a great system. It starts and runs perfectly at all altitudes. Just because someone doesn't understand it doesn't mean it's bad. Sure, he likes carbs (IMG:style_emoticons/default/laugh.gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
phatnine11
post Apr 18 2019, 11:39 AM
Post #7


Member
**

Group: Members
Posts: 286
Joined: 22-March 05
From: Rancho Cucamonga, CA
Member No.: 3,798



Won't idle when the engine warms up? I would check the AAR valve, very easy to do. Use a pair of vice grip pliers and clamp off the hose that runs from the air cleaner to the valve. If the car idles now, the problem is with the valve. I would look up the procedures for testing/ cleaning the valve. Without going into too much detail, this valve needs 12 volts to operate correctly. sometimes they freeze up.
Good luck,
Phatnine11
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
buck toenges
post Apr 18 2019, 11:45 AM
Post #8


Senior Member
***

Group: Members
Posts: 553
Joined: 25-November 03
From: Fort wayne In
Member No.: 1,388
Region Association: None



Does the 1973 1.7 have the air intake temp sensor that hooks into the plenum? It is by the throttle body. The 1973 2.0L has it. If the 1.7L has it, disconnect it from the wiring harness. The pet catalog says that it is part of the 1.7L. That will up the rpms slightly. That is what I did when my 2.0L engine warmed up and started to stumble and lose rpms at idle. Brad Mayeur told me that with these old engines you can't always find the answer on issues and that the tps 1 sensor isn't needed. He says it lowers mpg but the rpms at idle improves.

The part number is 311906081a

Buck
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
914_teener
post Apr 18 2019, 01:31 PM
Post #9


914 Guru
*****

Group: Members
Posts: 5,193
Joined: 31-August 08
From: So. Cal
Member No.: 9,489
Region Association: Southern California



QUOTE(mgphoto @ Apr 17 2019, 06:09 PM) *

QUOTE(tsvo @ Apr 17 2019, 05:44 PM) *

I have a 1973, 1.7 with FI still on it. The car is stalling at idle after the engine warms up. Any ideas what to adjust or look for? Things that may be contributing, but not sure. I think there is a vaccum leak. It smells like it is running rich. I recently replaced the fuel pump.

Any help is much appreciated.

Thanks,
Terry

Check the MPS, see if it holds vacuum and for how long.
Air leak would cause fast idle.
Check for kinked fuel line?



+1


And...


Ignore the Trolls.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
thelogo
post Apr 18 2019, 04:30 PM
Post #10


Senior Member
***

Group: Retired Members
Posts: 1,510
Joined: 6-April 10
Member No.: 11,572
Region Association: None



QUOTE(thelogo @ Apr 18 2019, 06:26 AM) *

Once d jet stops working .
The really problem could be anywhere
And beyond guessing and hopeing
There is no way to test or identifyi the issue or soultion short of replacing or rebuilding all components that are nla

So if it still runs it is in some form of compromised
Performance aka limp mode .

I love it when something that supposed to last 10 years go's strong for 50yrs. And when it fails it fails slowly (Djet)

But

I hate it when cars or planes catch on fire
Don't ignore the warning signs








(IMG:style_emoticons/default/smoke.gif) hey you dont have to trust me
Just listen to what im saying to you

When djet parts and techs are plentful
I will stop being a fan of carbs aka (dead tech)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
tsvo
post Apr 23 2019, 11:29 AM
Post #11


Member
**

Group: Members
Posts: 123
Joined: 30-January 16
From: Chicago
Member No.: 19,616
Region Association: Upper MidWest



QUOTE(Rand @ Apr 17 2019, 10:37 PM) *

(IMG:style_emoticons/default/agree.gif)
Vacuum leaks on Djet usually cause high idle. An exception is the MPS which fails to full rich if it doesn't hold a vacuum (whether via the hose or the diaphragm within).

If you pull the vacuum hose off the MPS while it's running, what changes?


Thank you, I will be working on it this weekend. I appreciate your help.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
tsvo
post Apr 23 2019, 11:29 AM
Post #12


Member
**

Group: Members
Posts: 123
Joined: 30-January 16
From: Chicago
Member No.: 19,616
Region Association: Upper MidWest



QUOTE(Rand @ Apr 17 2019, 10:37 PM) *

(IMG:style_emoticons/default/agree.gif)
Vacuum leaks on Djet usually cause high idle. An exception is the MPS which fails to full rich if it doesn't hold a vacuum (whether via the hose or the diaphragm within).

If you pull the vacuum hose off the MPS while it's running, what changes?


Thank you
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
tsvo
post Apr 23 2019, 11:30 AM
Post #13


Member
**

Group: Members
Posts: 123
Joined: 30-January 16
From: Chicago
Member No.: 19,616
Region Association: Upper MidWest



QUOTE(buck toenges @ Apr 18 2019, 12:45 PM) *

Does the 1973 1.7 have the air intake temp sensor that hooks into the plenum? It is by the throttle body. The 1973 2.0L has it. If the 1.7L has it, disconnect it from the wiring harness. The pet catalog says that it is part of the 1.7L. That will up the rpms slightly. That is what I did when my 2.0L engine warmed up and started to stumble and lose rpms at idle. Brad Mayeur told me that with these old engines you can't always find the answer on issues and that the tps 1 sensor isn't needed. He says it lowers mpg but the rpms at idle improves.

The part number is 311906081a

Buck



Thank you, I will be working on it this weekend. I appreciate your help.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
tsvo
post Apr 23 2019, 11:31 AM
Post #14


Member
**

Group: Members
Posts: 123
Joined: 30-January 16
From: Chicago
Member No.: 19,616
Region Association: Upper MidWest



QUOTE(Rand @ Apr 17 2019, 10:37 PM) *

(IMG:style_emoticons/default/agree.gif)
Vacuum leaks on Djet usually cause high idle. An exception is the MPS which fails to full rich if it doesn't hold a vacuum (whether via the hose or the diaphragm within).

If you pull the vacuum hose off the MPS while it's running, what changes?


Thank you, I will be working on it this weekend. I appreciate your help.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
windforfun
post Apr 23 2019, 02:32 PM
Post #15


Senior Member
***

Group: Members
Posts: 1,771
Joined: 17-December 07
From: Blackhawk, CA
Member No.: 8,476
Region Association: None



I simply raised the idle to about 1,500 rpm when cold. After it warms up, the idle drops to about 1,000 rpm & stays there.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
dr914@autoatlanta.com
post Apr 23 2019, 02:53 PM
Post #16


914 Guru
*****

Group: Members
Posts: 7,811
Joined: 3-January 07
From: atlanta georgia
Member No.: 7,418
Region Association: None



check the dwell angle first, closed points make many assume that they have a fuel injection problem. After that check to see that the engine is running on all four cylinders then check to see if the pressure sensor is leaking vacuum causing too rich a mixture


QUOTE(tsvo @ Apr 17 2019, 05:44 PM) *

I have a 1973, 1.7 with FI still on it. The car is stalling at idle after the engine warms up. Any ideas what to adjust or look for? Things that may be contributing, but not sure. I think there is a vaccum leak. It smells like it is running rich. I recently replaced the fuel pump.

Any help is much appreciated.

Thanks,
Terry
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
tsvo
post Apr 23 2019, 07:15 PM
Post #17


Member
**

Group: Members
Posts: 123
Joined: 30-January 16
From: Chicago
Member No.: 19,616
Region Association: Upper MidWest



QUOTE(dr914@autoatlanta.com @ Apr 23 2019, 03:53 PM) *

check the dwell angle first, closed points make many assume that they have a fuel injection problem. After that check to see that the engine is running on all four cylinders then check to see if the pressure sensor is leaking vacuum causing too rich a mixture


QUOTE(tsvo @ Apr 17 2019, 05:44 PM) *

I have a 1973, 1.7 with FI still on it. The car is stalling at idle after the engine warms up. Any ideas what to adjust or look for? Things that may be contributing, but not sure. I think there is a vaccum leak. It smells like it is running rich. I recently replaced the fuel pump.

Any help is much appreciated.

Thanks,
Terry



Thank you, I will check your suggestions. I appreciate the response.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 19th April 2024 - 08:22 PM