Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > 911 / 930 Turbo & Super Charging Forum


Reply
 
LinkBack Thread Tools Rating: Thread Rating: 4 votes, 3.25 average.
Author
Thread Post New Thread    Reply
Certified User
 
billjam's Avatar
 
Join Date: Aug 2007
Location: Perth, Western Australia
Posts: 1,986
Garage
Brian,
It seems many of us have "been there" with this damn green wire. I had similar symptoms and a new "green" wire fixed it.

I couldn't source any coax wire the same size as the green wire so I used some shielded twisted pair cable left over from knock sensor wiring on my project 3.6 engine (from RadioShack).
I joined the two core wires at each end to effectively give me a total core wire size of 0.6mm2. The shield was only 0.3 so I beefed it up with a extra 0.5mm2 single wire heat-shrinked in parallel and it works just fine.

Initially, I made up a complete separate harness from CDI to coil and distributor and ran the car that way for a few months. Once I was happy it was OK, I stripped the old wires from the engine harness and made my temporary CDI harness permanent with a 2 pin connector into the engine harness for 12V supply and tach signal.
I figured that if I had problems with it again, it would be much simpler to deal with the CDI and dizzy wiring if it wasn't embedded in the main harness.
The CDI harness is blue, engine harness is grey.

__________________
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 11-27-2012, 02:47 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #441 (permalink)
Crotchety Old Bastard
 
RarlyL8's Avatar
 
Join Date: Jan 2000
Location: Huntsville, AL
Posts: 13,723
Garage
Nice diagram, thank you!

The fuel pressures are in spec when the issue occurs, both warm and system.
__________________
RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 11-27-2012, 09:33 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #442 (permalink)
Crotchety Old Bastard
 
RarlyL8's Avatar
 
Join Date: Jan 2000
Location: Huntsville, AL
Posts: 13,723
Garage
Well we have some interesting data today.

I stole an hour and changed the spark pug wires. The old ones appeared to be in pretty bad shape as the connectors that plugged into the dizzy were corroded.





Replaced with a nice new perfect wires.





Fired the engine and you guessed it, NO CHANGE.

Ran rough above 1500rpm until the warm pressure reached spec then smoothed out a little. Let the emgine idle for a few minutes while I checked a few things.
Shut the engine down and after 5 min fired up again. This time it ran a bit rough at idle as well.

Here is where we get another clue.
Put the car in gear and started down the driveway - and the engine DIED. An attempt at cranking fired once then no more.

> Gages went wacko when key turned to 2nd detent, did NOT hear CDI box.

My son and I pushed the car into the garage and I hit the key again for fun and this time the gages did not go wacky and the CDI box whistled as it should.

OK electrical gurus, what do we have here?

I no longer think the green wire is the culprit. Now I'm thinking relays or ignition switch.
Tell yu one thing, once this problem is solved the SOB is gonna run like a scalded cat with all this new ignition rear!!
__________________
RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 12-08-2012, 02:39 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #443 (permalink)
Registered User
 
oilonly's Avatar
 
Join Date: May 2008
Posts: 1,148
Just throwing this out there , Voltage regulator?
__________________
'87, Modified WUR, Billet valve, 965 downpipe, Kokeln intercooler, GHL headers, Garrett T04B K27 hybrid, Tial w/.8 bar, WEGO IV, RarlyL8 dual out, LSD
Old 12-08-2012, 03:15 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #444 (permalink)
Forced Induction Junkie
 
WERK I's Avatar
 
Join Date: Jan 2003
Location: Wisconsin
Posts: 3,291
Garage
Brian,
Could you remove a couple of spark plugs and inspect the electrodes just after the engine dies?
IMHO, this seems more of a fueling issue than ignition.

Why? Ignition woes get worse when engine loads increase (i.e. RPM/Boost). I may be way off base, but so what else is new?
__________________
Dave
'85 930 Factory Special Wishes Flachbau
Werk I Zuffenhausen 3.3l/330BHP Engine with Sonderwunsch Cams, FabSpeed Headers, Kokeln IC, Twin Plugged Electromotive Crankfire, Tial Wastegate(0.8 Bar), K27 Hybrid Turbo, Ruf Twin-tip Muffler, Fikse FM-5's 8&10x17, 8:41 R&P
Old 12-09-2012, 05:00 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #445 (permalink)
Aircooled Breakfast
 
Join Date: Dec 2007
Location: Wyoming
Posts: 605
I think Oilonly may be on to something. Have you checked system voltage when all of this is going on? When my alternator died my car would run great when the battery was fully charged (via trickle charger) but after driving a few minutes it would get progressively worse - missing and backfiring - until it would finally die. If you don't have one, get one of those voltage gauges that plug into the cigar lighter socket.

Quote:
Originally Posted by oilonly View Post
Just throwing this out there , Voltage regulator?
Old 12-09-2012, 06:33 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #446 (permalink)
Registered User
 
Join Date: Jul 2006
Location: S. Florida
Posts: 7,289
I can't remember if you have a wideband AFR gauge running in this car. If there is one what does it say when all this funky stuff is going on?

If there isn't one then.. well... whatever....
Old 12-09-2012, 07:10 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #447 (permalink)
Crotchety Old Bastard
 
RarlyL8's Avatar
 
Join Date: Jan 2000
Location: Huntsville, AL
Posts: 13,723
Garage
This is definitely an electrical issue. Remember the gages all went wacky after the engine died and I attempted a re-start. When the engine died it did so abruptly, as if turning off the key. When attempting to re-start the gages pointers all flew everywhere back and forth.

Quote:
Have you checked system voltage when all of this is going on? When my alternator died my car would run great when the battery was fully charged (via trickle charger) but after driving a few minutes it would get progressively worse - missing and backfiring - until it would finally die.
This may be a clue that I did not pay enough attention to.
I noted when using the LM1 to measure AFR's that the voltage registered on the meter was 10.5V and not 12-12.5V as it should have been. I dismissed this as old wiring to a corroded cigarette lighter. I checked the battery at that time and it was 12V so assumed the alternator was working properly.

So how/where do I test voltage regulation?
__________________
RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 12-09-2012, 07:16 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #448 (permalink)
Registered User
 
Join Date: Jul 2006
Location: S. Florida
Posts: 7,289
Maybe you just need to clean all the fuse contacts with electrical contact cleaner from a spray can.
Then pull off every electrical spade teminal you can find and squeeze the female terminal together with needle nose pliers a little so it fits tighter on the male terminal if it's a little loose. Spray it with contact cleaner first and see if it gets any better.

Then theres a bunch of those round rubber electrical plugs with the split male terminals in the car. One of them comes off the ignition switch and plugs into a rubber socket plug around 8 inches away in the chassis leading to the other side into the front trunk. Look up under the dah and you'll see it nearby the back side of the ignition switch.
If you unplug that one, even partially, the car won't start or run so it's one of many that need to be checked and the split male pins can be spread a little with a knife blade so they contact the metal in the female plug pin holes better.
Old 12-09-2012, 07:41 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #449 (permalink)
Aircooled Breakfast
 
Join Date: Dec 2007
Location: Wyoming
Posts: 605
Quote:
Originally Posted by RarlyL8 View Post
This may be a clue that I did not pay enough attention to.
I noted when using the LM1 to measure AFR's that the voltage registered on the meter was 10.5V and not 12-12.5V as it should have been. I dismissed this as old wiring to a corroded cigarette lighter. I checked the battery at that time and it was 12V so assumed the alternator was working properly.

So how/where do I test voltage regulation?
Check voltage at the battery with a digital VOM. You need to be seeing 13.5-14VDC when the engine is running at anything over idle speed. You may still have the external regulator which is on the relay panel in the engine compartment unless your alternator has been replaced with an internally regulated model at some point.

John
Old 12-09-2012, 10:07 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #450 (permalink)
Crotchety Old Bastard
 
RarlyL8's Avatar
 
Join Date: Jan 2000
Location: Huntsville, AL
Posts: 13,723
Garage
Thanks Jim for the tips, I planned to do that when we ripped out the alarm system. Unfortunately this problem came up right before that task was to be done.

My car is an '85 Euro John, I assumed the regulator was integral with the alternator. What year did they switch over?
__________________
RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 12-09-2012, 04:19 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #451 (permalink)
Aircooled Breakfast
 
Join Date: Dec 2007
Location: Wyoming
Posts: 605
I think they switched to internal regulators in '82(?). Have you had a chance to check voltage?

Quote:
Originally Posted by RarlyL8 View Post

My car is an '85 Euro John, I assumed the regulator was integral with the alternator. What year did they switch over?
Old 12-09-2012, 04:40 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #452 (permalink)
Crotchety Old Bastard
 
RarlyL8's Avatar
 
Join Date: Jan 2000
Location: Huntsville, AL
Posts: 13,723
Garage
Engine no longer fires so now it's on to tracing wires, jumping relays, and testing the alternator. Our mechanic Wayne is a master at all things electrical so it is really time to turn this lovely adventure over to an expert. Martin's shop is crammed full right now so it may be a while. In the mean time I may do some late night relay jumping ...
__________________
RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 12-09-2012, 06:32 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #453 (permalink)
Wide body, molester.
 
H20 LOL's Avatar
 
Join Date: Dec 2011
Location: San Antonio, Tx
Posts: 153
Good luck man, chasing electrical gremlins is high on my list of least favorite ways to spend time with my car.
__________________
91- 964T, It's upkeep treats me like a skinny white kid in prison, but it does give me a reach around every now and then by letting me drive it. That's not so bad.
Old 12-09-2012, 07:12 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #454 (permalink)
Crotchety Old Bastard
 
RarlyL8's Avatar
 
Join Date: Jan 2000
Location: Huntsville, AL
Posts: 13,723
Garage
He he, yes me too. I'm a true electri-tard. We're all too busy to mess with it now which is really the issue. These things take time to think about logical next steps so you don't make matters worse and the problem harder to find. That parasitic alarm system is a concern as it really complicates troubleshooting. We may end up removing it and fix everything properly along the way.
I do appreciate the help from you all and really miss driving my car!
__________________
RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 12-10-2012, 03:54 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #455 (permalink)
I've gone native
 
Tt surgeon's Avatar
 
Join Date: Sep 2011
Location: Long Island, NY
Posts: 1,697
Gotta be related to that alarm. Keep plugging away!
C
Old 12-11-2012, 03:00 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #456 (permalink)
Registered User
 
Join Date: Sep 2002
Location: Westchester County, NY
Posts: 1,727
Garage
Too bad we're such a small market. Over in muscle car land, Painless and American Autowire make some paint-by-numbers modern-fused harnesses that just nuke the electrical gremlin problem.
We're stuck with pocket knifes spreading male posts on relays under flashlight illumination at the side of a road. Every time my car starts I must admit I feel a wave of relief!
__________________
1986 930, 1969 Mach1, 2003 540 Sport, 2016 R1200RS
Old 12-11-2012, 06:57 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #457 (permalink)
Registered User
 
baloo's Avatar
Quote:
Originally Posted by gsxrken View Post
Every time my car starts I must admit I feel a wave of relief!
Well said and undeniable. The moment it doesn't catch on first crank, my mind is troubleshooting possible causes, and I can't help but think the worst-case scenarios first. The wife thinks of things like "gas" or "battery" or "tire" -- I'm thinking hidden ground wire, black box failure, buried frozen relay.
Old 12-12-2012, 01:45 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #458 (permalink)
Registered User
 
Join Date: Apr 2007
Location: Seattle
Posts: 1,816
Just wondering why you haven't replaced the green dizzy wire ? If it's not the problem it should be done anyway as it inevitably will fail, and probably not in the driveway.
Anyway, I hope you resolve it soon so you can get to driving the wheels off that bad boy.
Good luck.
__________________
81 Pacific Blue 930 Euro coupe slicktop on a strict diet, Rarlyl8 headers, Blowzilla turbo, Tial waste gate, Full bay I/C, Home made center out exhaust, Leask WUR, MSD 6AL, PLX wideband
Wevo shifter, LSD. Next up, Cams, Heads and port work
Old 12-12-2012, 09:05 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #459 (permalink)
Crotchety Old Bastard
 
RarlyL8's Avatar
 
Join Date: Jan 2000
Location: Huntsville, AL
Posts: 13,723
Garage
Wanted to do one thing at a time as we are documenting this. The green wire was next, however with the last chain of events we will move to the delay relay and ignition switch. I now have the parts to make a plug for the green wire and do plan to add that if for no other reason than making it a bunch easier to remove the distributor!
__________________
RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 12-12-2012, 09:31 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #460 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 09:24 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.