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

Need some suggestions
Goto page 1, 2  Next
 
Post new topic   Reply to topic    924Board.org Forum Index -> General Discussions
View previous topic :: View next topic  
Author Message
Mudd  



Joined: 27 Aug 2012
Posts: 78
Location: Cincinnati,Ohio

PostPosted: Fri May 03, 2013 5:12 am    Post subject: Need some suggestions Reply with quote

I have been fighting a high idle on my 1978 924. I removed the AAV and cleaned it and bench tested it and it opens and closes as it should. While I had it out I checked that it was getting 12volts to the electric connection with the ignition turned on. I also replaced all of the vacuum lines with Lindsey silicone lines. It is still idleing at 1500 rpm after warm up. Other than the high idle the car runs fine. What can I check next. This car has 18,500 original miles on it and has the original braided type hoses. Would you guys suggest replacing these hoses. Is it a good idea to take the air intake off the throttle and spray throttle cleaner in there. Please excuse my lack of proper terminology, I am an amatuer when it comes to car mechanics.
I thought I had it fixed when I replaced the vacuum lines because it idled at 950rpm in the garage even after it warmed up but jumped up to 1500 after a drive around the block. Any help will be appreciated.
_________________
1978 924
1987 944
Back to top
View user's profile Send private message
fiat22turbo  



Joined: 18 Jan 2006
Posts: 4040
Location: Portland, OR

PostPosted: Fri May 03, 2013 5:42 am    Post subject: Reply with quote

Check the bushings around the throttle shafts in the throttle body. Try to spray some carb cleaner/mist of water in the area to see if the idle changes at all.

Double check the air intake boot between the CIS system (the large box of hoses in the nose of the car) and the intake manifold.

Might check to see if your timing is correct as well. Perhaps the distributor slipped slightly?
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)
Back to top
View user's profile Send private message Visit poster's website
joemac  



Joined: 22 Apr 2013
Posts: 44
Location: SE Pa.

PostPosted: Fri May 03, 2013 8:15 am    Post subject: Reply with quote

Spray some carb cleaner/ether around the injectors while it's idling.
The injector "O" rings are known to dry out over time and lose their sealing properties. If they're leaking, you can have a very erratic idle, usually high when warmed up.
_________________
Race car: my favourite palindrome.
Porsche: my favourite race car.
Back to top
View user's profile Send private message
Mudd  



Joined: 27 Aug 2012
Posts: 78
Location: Cincinnati,Ohio

PostPosted: Fri May 03, 2013 10:01 am    Post subject: Reply with quote

I sprayed carb cleaner on the injectors and two of them caused a change in the idle. Is the injector seal the black donut shaped one I found on Pelican. Is this the only seal or is there more to sealing the injectors. What the process to seal the injectors.
_________________
1978 924
1987 944
Back to top
View user's profile Send private message
fiat22turbo  



Joined: 18 Jan 2006
Posts: 4040
Location: Portland, OR

PostPosted: Fri May 03, 2013 10:20 am    Post subject: Reply with quote

Yup, the O-ring and the plastic housings that screw into the head is all there is that is holding the injectors in place.

Rarely do the plastic housings fail and usually the injector seals or O-rings fail.

The injectors fit in the housings very snugly with the O-rings holding them in place.

BE VERY CAREFUL REMOVING THE INJECTORS YOU CAN BREAK A FUEL FITTING VERY EASILY!

I've not had much success myself, but I've only ever done it once so I'll let the more experienced folks provide tips and tricks to make it less harrowing for you.
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)
Back to top
View user's profile Send private message Visit poster's website
Mudd  



Joined: 27 Aug 2012
Posts: 78
Location: Cincinnati,Ohio

PostPosted: Fri May 03, 2013 10:26 am    Post subject: Reply with quote

thanks for the help guys. My question now is should I also replace the plastic part and what is the best way to get the injectors out and back in without screwing something up.
_________________
1978 924
1987 944
Back to top
View user's profile Send private message
joemac  



Joined: 22 Apr 2013
Posts: 44
Location: SE Pa.

PostPosted: Fri May 03, 2013 11:20 am    Post subject: Reply with quote

Since you asked, the BEST way to remove the injectors is to use the special tool that fits under the base of the injector, and then pry (prise for our British folk) against the head in an upward motion.
They can be stuck in there rather well, since the O rings are hardened from time and thermocycles.

Failing having the correct tool, a pair of Vice-grips snapped onto the injector base and a prybar will get you there.
Wiggle and pry, wiggle and pry.
A short blast of carb cleaner at the injector will offer a short-duration form of lubricant.

You shouldn't have to replace the phenolic inserts.
_________________
Race car: my favourite palindrome.
Porsche: my favourite race car.
Back to top
View user's profile Send private message
Mudd  



Joined: 27 Aug 2012
Posts: 78
Location: Cincinnati,Ohio

PostPosted: Fri May 03, 2013 11:34 am    Post subject: Reply with quote

Thanks joemac that is what I was looking for. Where do you get the special tool..
_________________
1978 924
1987 944
Back to top
View user's profile Send private message
joemac  



Joined: 22 Apr 2013
Posts: 44
Location: SE Pa.

PostPosted: Sat May 04, 2013 7:47 am    Post subject: Reply with quote

http://www.youtube.com/watch?v=TmRlIw9VVZc
_________________
Race car: my favourite palindrome.
Porsche: my favourite race car.
Back to top
View user's profile Send private message
Mudd  



Joined: 27 Aug 2012
Posts: 78
Location: Cincinnati,Ohio

PostPosted: Sat May 04, 2013 12:42 pm    Post subject: Reply with quote

Thanks for the video, I search for two days for anything about pulling the 924 injectors with no luck. I used your vice grip and pry bar method and it worked great. One final question, can I use WD 40 on the O ring and injector when installing it.
_________________
1978 924
1987 944
Back to top
View user's profile Send private message
Mudd  



Joined: 27 Aug 2012
Posts: 78
Location: Cincinnati,Ohio

PostPosted: Wed May 22, 2013 10:43 am    Post subject: Reply with quote

Replaced the injector O rings and checked anything to do with air with carb cleaner. Still a high idle after driving for a mile or so. This is very frustrating. Any suggestions would be appreciated.
_________________
1978 924
1987 944
Back to top
View user's profile Send private message
staticsan  



Joined: 19 Jan 2009
Posts: 450
Location: Sydney, Australia

PostPosted: Wed May 22, 2013 2:07 pm    Post subject: Reply with quote

This might be a long shot, but a mixture that's too rich will cause a high idle, too. Unfortunately, you really need a gas sniffer in the tailpipe to set the mixture right.

The mixture is adjusted by putting a long 3mm allen key down a hole in the metering box beside the fuel distributor.

Wade.
_________________
'82 British NA - Which I think I've been very lucky with!
Back to top
View user's profile Send private message
scriblz7  



Joined: 07 Dec 2008
Posts: 112
Location: kirkland WA.

PostPosted: Wed May 22, 2013 4:02 pm    Post subject: Reply with quote

check your fuel system and control pressures. the warm up regulator may be gummed up and giving you an incorrect control pressure when warm.
_________________
Riley
79 924 n/a with gt body
15 VW GTI
Back to top
View user's profile Send private message
!tom  



Joined: 28 Aug 2006
Posts: 1908
Location: Victoria, BC Canada

PostPosted: Wed May 22, 2013 5:40 pm    Post subject: Reply with quote

staticsan wrote:
This might be a long shot, but a mixture that's too rich will cause a high idle, too.

I thought a well established procedure for setting the mixture in the absense of the correct sniffer equipment was to adjust the mixture for maximum RPM at idle.
_________________
78 924 NA
5-lug
Back to top
View user's profile Send private message Visit poster's website
Rasta Monsta  



Joined: 12 Jul 2006
Posts: 11410
Location: PacNW

PostPosted: Thu May 23, 2013 1:59 am    Post subject: Reply with quote

Has someone fiddled with the throttle stop? Does your car have an idle air bypass circuit, and have you tried adjusting it?
_________________
Toofah King Bad
  • WeiBe (1987 924S) - 931 S3
  • Red (1987 924S) - Pro44/Spec944
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> General Discussions All times are GMT + 11 Hours
Goto page 1, 2  Next
Page 1 of 2

 
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