Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

'83 931 idles like a dog when cold - It's fixed!
Goto page Previous  1, 2, 3  Next
 
Post new topic   Reply to topic    924Board.org Forum Index -> 931 Tech.
View previous topic :: View next topic  
Author Message
knobby  



Joined: 23 May 2011
Posts: 33
Location: Cincinnati,Ohio

PostPosted: Fri Aug 11, 2017 3:17 am    Post subject: Reply with quote

I noticed that the vacuum diagrams you posted all include the frequency valve .If only USA spec has frequency/LAMBDA then it would seem that more than likely there are also differences with the vacuum line routing and therefore maybe the diagram you are using is a USA spec.
_________________
81 RED 931 S2(daily driver),81 WHITE 931 S2(not currently drivable).
Cincinnati,Ohio
Back to top
View user's profile Send private message
Dutch924-racer  



Joined: 23 Jul 2007
Posts: 1000
Location: The Netherlands

PostPosted: Fri Aug 11, 2017 4:19 am    Post subject: Reply with quote

I run this vacuum line setup. Just forget K/7/11; purge valve, etc.

I also have a cis tester that i might sell.



_________________
937 trackday car
Series 2 engine
951S turbo and intercooler
937 DITC
Fast road camshaft
Forge recirculation valve + boost controller


Last edited by Dutch924-racer on Thu Aug 17, 2017 3:30 am; edited 1 time in total
Back to top
View user's profile Send private message
Johann  



Joined: 07 Aug 2016
Posts: 163
Location: Netherlands

PostPosted: Mon Aug 14, 2017 5:50 pm    Post subject: Reply with quote

Thanks, I will reroute those lines when I get into the CIS in a week or two. I might also take you up on your CIS Parts Dutch924-racer.

I have now ordered a CIS Tester, New correct pump( this time specifying the Bosch part number as well). Within a couple of days I should have all the required parts to fix this problem once and for all.
Back to top
View user's profile Send private message AIM Address
morghen  



Joined: 21 Jan 2005
Posts: 7806
Location: Romania

PostPosted: Mon Aug 14, 2017 7:13 pm    Post subject: Reply with quote

Good luck...but I think the best investment is a wide band sensor and gauge.
Even if your WUR and CIS is working as it should be, you may be overfueling when cold and with the "right" spark plugs you may get the effect you're having.

When overfueled my 924s also run like crap cold...but once they warm up its all good and smooth. Try leaning out the mixture 1/4 turns or 1/2 turns and see if it fires up better when cold.
_________________
red 924 and not red 924
Back to top
View user's profile Send private message Visit poster's website Yahoo Messenger MSN Messenger
Johann  



Joined: 07 Aug 2016
Posts: 163
Location: Netherlands

PostPosted: Tue Aug 15, 2017 8:02 am    Post subject: Reply with quote

Thanks Morghen, I would love to install a wide band sensor, but I do not want to add any gauges to my car. My 931, other than my 911, is bone stock and I want to keep it looking this way.

If there is a wide band sensor out there that works with Bluetooth or something similar that would be the perfect solution.
Back to top
View user's profile Send private message AIM Address
morghen  



Joined: 21 Jan 2005
Posts: 7806
Location: Romania

PostPosted: Tue Aug 15, 2017 8:28 am    Post subject: Reply with quote

I'm sure there is a bluetooth capable system out there.
But you dont have to alter its looks in any way, i did not want an ugly christmas tree gauge in my 924 either so i just tossed the gauge in the place of the central speaker. Its covered modt of the time so not visible unless i take the cover off.
_________________
red 924 and not red 924
Back to top
View user's profile Send private message Visit poster's website Yahoo Messenger MSN Messenger
Johann  



Joined: 07 Aug 2016
Posts: 163
Location: Netherlands

PostPosted: Tue Aug 15, 2017 11:48 pm    Post subject: Reply with quote

I found this and seems exactly like what I need....tempting
Back to top
View user's profile Send private message AIM Address
Dutch924-racer  



Joined: 23 Jul 2007
Posts: 1000
Location: The Netherlands

PostPosted: Thu Aug 17, 2017 3:29 am    Post subject: Reply with quote

Nice find!
_________________
937 trackday car
Series 2 engine
951S turbo and intercooler
937 DITC
Fast road camshaft
Forge recirculation valve + boost controller
Back to top
View user's profile Send private message
Johann  



Joined: 07 Aug 2016
Posts: 163
Location: Netherlands

PostPosted: Thu Aug 17, 2017 4:50 am    Post subject: Reply with quote

OK, now I am confused

Today I received my new fuel pump directly from Porsche, and guess what...they sent me Bosch 0 580 464 126.

I already have this pump under my car and only paid a third of the price Porsche charged me for the one they sent me today. The new one is going back, so in the end I am no poorer, but now I am a little lost.

According to my parts dealer Bosch 0 580 464 126 = 911.608.102.02

Please share your wisdom.
Back to top
View user's profile Send private message AIM Address
morghen  



Joined: 21 Jan 2005
Posts: 7806
Location: Romania

PostPosted: Thu Aug 17, 2017 5:51 am    Post subject: Reply with quote

there are two types of pump, long neck and short neck...

Here is the long neck one..i have this on my 931, it came like this from the factory.
0 580 254 982


_________________
red 924 and not red 924
Back to top
View user's profile Send private message Visit poster's website Yahoo Messenger MSN Messenger
Dutch924-racer  



Joined: 23 Jul 2007
Posts: 1000
Location: The Netherlands

PostPosted: Thu Aug 17, 2017 6:20 pm    Post subject: Reply with quote

I run a 6.5 bar Pierburg pump for 5 years now. Works great, cis tests pressures are exactly like in the manual.
_________________
937 trackday car
Series 2 engine
951S turbo and intercooler
937 DITC
Fast road camshaft
Forge recirculation valve + boost controller
Back to top
View user's profile Send private message
Johann  



Joined: 07 Aug 2016
Posts: 163
Location: Netherlands

PostPosted: Thu Aug 17, 2017 10:30 pm    Post subject: Reply with quote

I have spoken to my parts supplier and he says that up to 1980 Porsche specifies Bosch 0 580 254 984, but from 1980 Porsche specifies Bosch 0 580 464 126 . My search on the internet has told me that the alternative pump runs at 6.5 Bar, delivers 255 Liters Per Hour and has the long neck.



This looks like the pump Morghen has and has 6.5 bar like Dutch924-racer's pump.

This will not be the first time Porsche PET is incorrect, so I want to be 100% sure I get the correct pump.

Is there a spec difference for S1 and S2? Does the S2's system run on lower pressure? Can someone point me to some literature?
Back to top
View user's profile Send private message AIM Address
morghen  



Joined: 21 Jan 2005
Posts: 7806
Location: Romania

PostPosted: Thu Aug 17, 2017 10:58 pm    Post subject: Reply with quote

The only difference between all these pumps is when they were produced and where. Their specs are identical..it does not matter which pump you use..it will work perfectly. In the years of production some part numbers were replaced by others as suppliers changed their production site to save money and avoid taxes...and so on.
Just make sure the interface to your car will match and fit to the pump you're buying, it really does not matter from a performance point of view which pump you're using(out of those 3 part numbers).
_________________
red 924 and not red 924
Back to top
View user's profile Send private message Visit poster's website Yahoo Messenger MSN Messenger
Johann  



Joined: 07 Aug 2016
Posts: 163
Location: Netherlands

PostPosted: Wed Aug 30, 2017 12:34 am    Post subject: Reply with quote

Last week Friday I took all the components of the K-jetronic system to a local CIS guru for diagnostics. I not only took the parts coming of my car, but also the spare parts I have collected over the past year. My goal was to build a working and balanced set and rebuild components where necessary.

Early Saturday morning the first results came in...

De distributor delivered equal amounts of fuel across the four injector ports. However, system pressure was only 5.3 Bar. After playing around with shims he managed to get the system pressure up to the required 5.7 Bar



Then he started testing the WUR's. De WUR coming out of the car was, as I suspected, blocked. Luckily my backup WUR is ok and will be going into my car.


The WUR's were tested when cold (10℃) and warm as well as monitoring the warming cycle. Added to this they were also tested under boost when cold and hot. Now at leats I know the car will be getting the correct amount of fuel and the WUR and Distributor are balanced together.

The next tests were done on the injectors.

The old injectors were worthless. They opened way below 2 bar, the misting was terrible and one injector could not manage more than a couple of drips.


The new injectors are nicely balanced with a nice mist and delivering equal amounts of fuel. The only problem is that they open at 2.8 bar and according to the spec sheet this should be 3.3 bar. For now I am going to live with it since the information on this site tells mee anything above 2.5 bar is ok


Tonight I will be picking up all my components again and then I have the challenge to get the car running again before Saturday morning
Back to top
View user's profile Send private message AIM Address
morghen  



Joined: 21 Jan 2005
Posts: 7806
Location: Romania

PostPosted: Wed Aug 30, 2017 12:46 am    Post subject: Reply with quote

Nice, I hope you have a wideband sensor to tune the mixture right.
_________________
red 924 and not red 924
Back to top
View user's profile Send private message Visit poster's website Yahoo Messenger MSN Messenger
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> 931 Tech. All times are GMT + 11 Hours
Goto page Previous  1, 2, 3  Next
Page 2 of 3

 
Jump to:  
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 vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group