Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

Studder under load

Thread Tools
 
Search this Thread
 
Old 05-15-2009, 12:29 PM
  #1  
killingmoon65
Racer
Thread Starter
 
killingmoon65's Avatar
 
Join Date: May 2005
Location: South Detroit
Posts: 313
Likes: 0
Received 0 Likes on 0 Posts
Default Studder under load

Okay, I have recently posted a stall out problem on my 78 which I thought I had fixed but now something totally different is happening. The engine used to idle around 1500rpm but now it is around 900. It starts and idles fine but as soon as I get on the gas in gear, it sputters and if I blip the pedal I can actually get it to catch and rev it out and pull away. The mystery to me is that she ran perfect just recently and this just happened after a rain. I have read all the posts I could on the CIS I still I am left confused. I am tempted to pull the top of the intake off to check everything underneath but only as a last resort.
I will take apart the WUR and go from there. The posts I have read already were awesome but I can't find a similar problem so far. I have no gauges to check for line pressures. I can confirm both fuel pumps working and only two years old. Recent tune up bits installed. I have not touched any adjustments screws or messed with any settings yet.
I'm back out there now and will report any findings as they come up.
Old 05-15-2009, 01:26 PM
  #2  
Mrmerlin
Team Owner
 
Mrmerlin's Avatar
 
Join Date: May 2004
Location: Philly PA
Posts: 28,274
Received 2,455 Likes on 1,378 Posts
Default

whoa , try looking into the hot post connection, disconnect the battery first and clean all of the battery connections, some cars will leak water onto the ground connection in the rear of the car.
Then clean the hot post and open the 14 pin connector and look for corrosion if you dont have a hot post cover then get one a cover from a 88S4 will work, if the hot post gets wet then it will cause other things to fail.
Also check the connection at the brain remove the connector.
also check the connections of the coil wire and the green wire .
also remove the cap and see if has water in it.
also check the CE panel for water tell tales, pull some of the fuses out and see if they have corrosion if so then the blower box needs a reseal
Old 05-15-2009, 02:41 PM
  #3  
123quattro
Drifting
 
123quattro's Avatar
 
Join Date: Nov 2006
Location: Farmington Hills, MI
Posts: 2,973
Likes: 0
Received 1 Like on 1 Post
Default

This sounds like spark. Cap, rotor, and plugs will run you less than $100. Probably worth changing all of them anyway.
Old 05-15-2009, 03:26 PM
  #4  
sharknoob
Pro
 
sharknoob's Avatar
 
Join Date: Jun 2008
Location: Buffalo N,Y
Posts: 632
Likes: 0
Received 0 Likes on 0 Posts
Default

In your other post you said you found some bare wires, How did you fix them and if that was the green wire I would start there.
Old 05-15-2009, 05:26 PM
  #5  
killingmoon65
Racer
Thread Starter
 
killingmoon65's Avatar
 
Join Date: May 2005
Location: South Detroit
Posts: 313
Likes: 0
Received 0 Likes on 0 Posts
Default

I just replaced the cap, rotor, plugs and air filter. Ran like a champ but only until the first rain. It definitely feels like a fule starvation problems as there is no misfiring or backfiring. I will get back out there and have a look at the battery box as I have not been in there since I replaced the battery 6 years ago. Ground strap from engine to chassis was just cleaned up when I did the tune up so I can rule that out too.
MrMerlin, thanks for the list. I will go through it and see. Thanks all.
Old 05-15-2009, 06:52 PM
  #6  
Mrmerlin
Team Owner
 
Mrmerlin's Avatar
 
Join Date: May 2004
Location: Philly PA
Posts: 28,274
Received 2,455 Likes on 1,378 Posts
Default

6 years is a long time to not see your battery.......WOW.
Pretty strong chance the battery ground wire is not a s clean as it was 6 years ago, remove every connection and clean with a pink eraser
Might be a good idea to check and see if you might have water in the gas,
Check the locking cap and pull off the line to the pump and let some fuel drain into a big can and check



Quick Reply: Studder under load



All times are GMT -3. The time now is 05:25 PM.