Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 914 & 914-6 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Bruce Allert's Avatar
 
Join Date: Jun 2002
Location: Boring, Oregon
Posts: 917
Exclamation Idles better w/o Cold start Valve HELP!

Just installed new TPS on 73 1.7 EB (Calif) but car still would not want to run after AAR closed. Had to keep bumping throttle. No adjustment helped until I unplugged the cold start valve. Why? What's my problem? I drove it to town to see how it reacted to this condition and it was kinda sluggish and had a slight buck or suttle miss. I read various posts but couldn't come up with anything. Read about the thermotime switch in one post but it was said only the 75-76's had that.
HELP PLEASE
bruce
__________________
Sit'n here
Hav'n a beer.
Punkin's gone
(sniff)
Gotta mow the Lawn...
Old 12-26-2002, 05:34 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Administrator
 
Dave at Pelican Parts's Avatar
 
Join Date: Dec 1969
Location: Silly-Con Valley
Posts: 14,062
Garage
Send a message via AIM to Dave at Pelican Parts Send a message via Yahoo to Dave at Pelican Parts
Did you just unplug the electrical connector? If that changed anything, then I think your CSV is mis-wired.

The CSV should have zero effect on the car while it is running.

The valve needs two things to open up. It needs power on one pin of its connector, and it needs ground on the other pin. The ground is provided by the thermo-switch, which grounds its input if the temperature is "low enough". (How low? Not sure.) The power is hooked into the yellow wire that goes from the key to the starter. It only gets power when the starter motor is cranking. Not at any other time.

So the CSV should open up only when the starter is cranking, if it is also "cold enough".

If you mean that you clamped the hose going to the valve and things got better (or worse!), then I would say that the CSV is leaking fuel.

--DD
__________________
Pelican Parts 914 Tech Support

A few pics of my car: http://www.pelicanparts.com/gallery/Dave_Darling
Old 12-26-2002, 08:06 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
Bruce Allert's Avatar
 
Join Date: Jun 2002
Location: Boring, Oregon
Posts: 917
Yes, all I did was unplug it. (I unplugged what I think is the cold start) It is directly opposite of the TPS plug correct? This started happining after I switched the injector boots (plug ins) because mine weren't "black in back" as I had read so I switched them to see if it made a difference in the way it ran... it was worse, so I put them back. After I did that it went down hill from there. I'd though I may have turned the pressor sensor plug around so I tried plugging it in after turning the plug a full 180. That didn't help either.
This really all began after I disconnected the decel valve and plugged the fitting to the air intake distributor.
bruce
__________________
Sit'n here
Hav'n a beer.
Punkin's gone
(sniff)
Gotta mow the Lawn...
Old 12-26-2002, 09:16 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
Bruce Allert's Avatar
 
Join Date: Jun 2002
Location: Boring, Oregon
Posts: 917
A light just went on!!! I bet I'm unplugging the thermo switch! and, if I am, does that mean the switch is bad since it runs better w/o it?
bruce
__________________
Sit'n here
Hav'n a beer.
Punkin's gone
(sniff)
Gotta mow the Lawn...
Old 12-26-2002, 09:24 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
hardflex's Avatar
 
Join Date: Sep 2002
Location: dfw tx
Posts: 3,952
your cold start valve is at the front of the throttle bodytowards the right. It has fuel lines connected to it also, so you can't miss it.

On my 1.7 djet, I have the decel valve removed, the aar plugged, so the only large vacuum lines hooked are the mps and the egr hose going to the oil fill. you could do worse for testing than to do the same.

the cold start valve can leak and richen the mixture, don't know if that's the case with yours or not. you'd probably see black soot coming out the exhaust if that was the case

What happens when you unplug one injector at a time, does the engine slow? by the way, when I switched my plugs front to back, it made very little difference at idle.

I'll look for more answers for you
__________________
72 914 2056: 74 9146 2.2: 76 914 2.0
Old 12-26-2002, 10:36 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
hardflex's Avatar
 
Join Date: Sep 2002
Location: dfw tx
Posts: 3,952
have you opened the idle adustment screw. If you had vacuum leaks before, it might be closed down too much to run after the vacuum leaks are gone
__________________
72 914 2056: 74 9146 2.2: 76 914 2.0
Old 12-26-2002, 10:47 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
Registered User
 
Bruce Allert's Avatar
 
Join Date: Jun 2002
Location: Boring, Oregon
Posts: 917
I went out last night at 10 to look at what I'd been unplugging and, sure enough, it's been the thermo switch. I feel really stupid . So, now I have another avenue to go down. I will look for posts regarding this switch and how to test it. I have another on the engine sitting on the floor. Hopefully it's ok. I will change the cold start injector also if need be. It's been having trouble starting cold lately too. THAT should'a told me what direction to look to. Guess I wasn't think'n far enough outside the box!
bruce
__________________
Sit'n here
Hav'n a beer.
Punkin's gone
(sniff)
Gotta mow the Lawn...
Old 12-27-2002, 05:35 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
pbanders's Avatar
 
Join Date: Jan 2001
Location: Phoenix, AZ
Posts: 1,113
Garage
Send a message via Yahoo to pbanders
Did you say it was opposite of the TPS? Are you certain it's the thermoswitch?

If what you unplugged was a two-pole connector on the wiring harness that goes to a sensor that's on top of the plennum (air box), then you unplugged your air temperature sensor. By doing so, you richened the mixture by about 10%. This "trick" often makes some cars that were previously a bit lean run better.

Maybe you could take some pictures of it and post them, it's pretty hard for us to figure out stuff from descriptions some times.
Old 12-27-2002, 07:39 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered User
 
Bruce Allert's Avatar
 
Join Date: Jun 2002
Location: Boring, Oregon
Posts: 917
Stupid & stupider-r-r-r

uh-huh, ya, that's right
Thanks Brad, you've painted the correct picture. It is a 2 pole connector directly opposite the TPS. I looked at the pictures in the on line catalog and found what the cold start valve looks like. It stands to reason that it would be close to the cold start injector.
Now, back to the air temp sensor. This must be what is refered to as the #1 temp sensor and the #2 is the head temp sensor?? I'll look for posts regarding the testing of the air temp. I have a new head temp unit to install since the wire is brittle.
bruce
__________________
Sit'n here
Hav'n a beer.
Punkin's gone
(sniff)
Gotta mow the Lawn...
Old 12-27-2002, 10:25 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 12:10 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - 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.