View Single Post
billjam billjam is offline
Certified User
 
billjam's Avatar
 
Join Date: Aug 2007
Location: Perth, Western Australia
Posts: 1,939
Garage
4000rpm on starter!

It looks like the electrical gremlins are at work in my 930.
I recently replaced a dead PermaTune CDI with a Bosch unit. At the same time, I checked out all the wiring (including the dreaded green one) and the voltage regulator and couldn't find any problems that might have fried the CDI, but in the two weeks since then, the car has started running very roughly when cold and when I crank the engine, the tacho reads 3-4000 revs

When it is warmed up, it runs fine and is still really strong on boost. Keep in mind that "cold" here is about 20*C, not F.

I am going to launch into this today to try and find the problem, but any hints would be appreciated.
Surely someone out there can join the dots for me:
  • tacho reads 4000 when cranking (but stable otherwise)
  • very rough running when cold
  • plenty of power once boost comes in
  • AFRs when running rough are 13-14 (I would have expected much lower if ignition is misfiring)
__________________
Bill
1988 Carrera - 3.6 engine (with ITBs, COPs, MS3X) and a whole set of turbo body panels waiting in the attic.
Day job ... www.sspowdercoat.com.au
Memories: '68 912, '72 911T, '80 911SC, '84 911, '85 930, '86 930, '87 911
Old 01-07-2012, 07:56 PM
  Pelican Parts Technical Article Directory    Reply With Quote #1 (permalink)