It is currently Tue Sep 16, 2014 4:23 am




Post new topic Reply to topic  [ 10 posts ] 
 Cold Start Difficulty/ rough Idle 
Author Message
Speed Limit Obeyer

Joined: Fri Jan 15, 2010 4:09 pm
Posts: 85
Location: texas
Post Cold Start Difficulty/ rough Idle
So car doesnt like to start in the cold and if it does it revs up slowly no power and rough idle but it will die if you dont keep giving it pedal

I am confused when I was home on R&R it ran find but it was warm well my family was going to take it out for me while I am away and this month its been really cold in texas

any help to trouble shoot would be nice I just need to get the thing started so they can get ti back in the shed till im home

gunna wait till it warms up a bit

if you know what it could be I am also curious how pricy are the parts it needs?

_________________
No Replacment for Displacement

1989 Porsche 928 S4 Auto 4spd Black Beauty (Friday Night Cruiser)
1982 Jeep CJ5 Renegade 350 TBI , 5 spd Stick (Toy)
2005 Infiniti G35 Sport Package Auto 5 spd (DD)
2003 Honda VTX 1300 5 spd (Bike)


Sat Feb 04, 2012 9:15 am
Profile
Webmaster
User avatar

Joined: Mon Jan 07, 2008 8:43 pm
Posts: 2297
Location: Sunny San Diego
Post Re: Cold Start Difficulty/ rough Idle
Put your year in your signature, this helps tremendously in troubleshooting as all 928's are not the same. To me, it sounds like your Cold Start Valve isn't working and/or AAV (Aux Air Valve). Take off your Air Box and put a cap full of fuel in directly in the throttle body opening. This should at least get it to start, stay on the pedal till it's warm enough to stay running on it's own. Get it to the shed and troubleshoot there.

_________________
1981 Porsche 928 "Euro" 4.5 Litre Auto Gunsmoke Metallic Flat - Black Interrior
1983 Porsche 928S "US" 4.7 Litre Auto Light Bronze (Copper) Metallic - Brown Interior


Sat Feb 04, 2012 10:16 am
Profile
Speed Limit Obeyer

Joined: Fri Jan 15, 2010 4:09 pm
Posts: 85
Location: texas
Post Re: Cold Start Difficulty/ rough Idle
Its a 1989 s4 Auto

_________________
No Replacment for Displacement

1989 Porsche 928 S4 Auto 4spd Black Beauty (Friday Night Cruiser)
1982 Jeep CJ5 Renegade 350 TBI , 5 spd Stick (Toy)
2005 Infiniti G35 Sport Package Auto 5 spd (DD)
2003 Honda VTX 1300 5 spd (Bike)


Sun Feb 05, 2012 4:07 am
Profile
Webmaster
User avatar

Joined: Mon Jan 07, 2008 8:43 pm
Posts: 2297
Location: Sunny San Diego
Post Re: Cold Start Difficulty/ rough Idle
I'm not too up on the later 928's, but I would think they would have the same system as far as cold starts. Give what i suggested a go to get your car back in the shed. I always hear of the Thermotime Switch always going bad on the S4's.

_________________
1981 Porsche 928 "Euro" 4.5 Litre Auto Gunsmoke Metallic Flat - Black Interrior
1983 Porsche 928S "US" 4.7 Litre Auto Light Bronze (Copper) Metallic - Brown Interior


Sun Feb 05, 2012 8:14 am
Profile
Granny Driver

Joined: Thu Feb 02, 2012 10:03 am
Posts: 33
Location: Eagle, Idaho
Post Re: Cold Start Difficulty/ rough Idle
If you need a cold start valve, i have one dont buy one. I was thinking it was part of my issues I was having and bought a new one. As long as it is the same one as the 16v cars, just pay fot the shipping and its yours.

Ramon

_________________
1982 Porsche 928 "US" 4.5l Auto(soon to be 5spd) Black exterior , tan/brown interior
1986 Porsche 928S "US" 5.0l Auto Black exterior, Black interior


Wed Feb 08, 2012 9:31 am
Profile
Speed Limit Obeyer
User avatar

Joined: Thu Mar 17, 2011 7:37 pm
Posts: 71
Location: Van Nuys, CA
Post Re: Cold Start Difficulty/ rough Idle
could be cold start valve sticking, but to be safe, i would check vacuum on fpr/dampeners and make sure the diaphrams havent busted due to the weather (fuel will be comming into the vacuum line upon suction), then the vacuum line to the ignition computer as the timing might be thrown off due to a leak.

WSM will help alot here :)


Hope this helps,
Jonathan.

_________________
Porsche 928S - 84 (Quartz Grey Metallic)
Automatic
Euro Intake manifold/Cams/Injectors, Headers
Left to do/fix: Sunroof,electric locks,some interior, paint body,replace hood lining, bad gas milage
A little of a fixer upper, but a labor of love!


Wed Feb 08, 2012 1:07 pm
Profile
Granny Driver

Joined: Thu Feb 02, 2012 10:03 am
Posts: 33
Location: Eagle, Idaho
Post Re: Cold Start Difficulty/ rough Idle
Thanks Kelanel! I have been looking for those as well again. You are the man!(or woman) lol

_________________
1982 Porsche 928 "US" 4.5l Auto(soon to be 5spd) Black exterior , tan/brown interior
1986 Porsche 928S "US" 5.0l Auto Black exterior, Black interior


Wed Feb 08, 2012 2:14 pm
Profile
Speed Limit Obeyer
User avatar

Joined: Thu Mar 17, 2011 7:37 pm
Posts: 71
Location: Van Nuys, CA
Post Re: Cold Start Difficulty/ rough Idle
lol im a guy. and any time :D.

_________________
Porsche 928S - 84 (Quartz Grey Metallic)
Automatic
Euro Intake manifold/Cams/Injectors, Headers
Left to do/fix: Sunroof,electric locks,some interior, paint body,replace hood lining, bad gas milage
A little of a fixer upper, but a labor of love!


Wed Feb 08, 2012 5:19 pm
Profile
Webmaster
User avatar

Joined: Mon Jan 07, 2008 8:43 pm
Posts: 2297
Location: Sunny San Diego
Post Re: Cold Start Difficulty/ rough Idle
Ha ha, you "guys"!!

_________________
1981 Porsche 928 "Euro" 4.5 Litre Auto Gunsmoke Metallic Flat - Black Interrior
1983 Porsche 928S "US" 4.7 Litre Auto Light Bronze (Copper) Metallic - Brown Interior


Wed Feb 08, 2012 5:45 pm
Profile
Granny Driver

Joined: Thu Feb 02, 2012 10:03 am
Posts: 33
Location: Eagle, Idaho
Post Re: Cold Start Difficulty/ rough Idle
Damnit! Where is the like button? Lol

_________________
1982 Porsche 928 "US" 4.5l Auto(soon to be 5spd) Black exterior , tan/brown interior
1986 Porsche 928S "US" 5.0l Auto Black exterior, Black interior


Wed Feb 08, 2012 5:48 pm
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 


Who is online

Users browsing this forum: No registered users and 0 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © phpBB Group.
Designed by Vjacheslav Trushkin for Free Forums/DivisionCore.