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 > Porsche 911 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Jun 2010
Location: Omaha
Posts: 7
Garage
My car won't start!

Any help troubleshooting would be greatly appreciated! It's '84 911 Cabrio, stock, with 50K miles. It's always run perfectly (at least since I've owned it 5 yrs), one day just wouldn't start. Turns over fine, no spark. Any ideas?

Old 06-23-2010, 08:19 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
<insert witty title here>
 
Christien's Avatar
 
Join Date: Nov 2004
Location: Hamilton, Ont.
Posts: 6,988
Garage
Do a search for no-start. Not to sound like a smart-ass search nazi, but I know this has come up here a billion times. It's either fuel or spark you're missing, and checking to determine is fairly straightforward.
__________________
Current: 1987 911 cabrio
Past: 1972 911t 3.0, 1986 911, 1983 944, 1999 Boxster
Old 06-24-2010, 06:08 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
Drisump's Avatar
 
Join Date: Sep 2009
Location: Galiano, BC
Posts: 1,404
Garage
I don't want to sound like a one hit wonder but an easy place to start is your DME relay located under your drivers seat. If you (or your cars previous owners), haven't already done this, it's time anyway (about $35). Cheers
Old 06-24-2010, 06:21 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
83 911 Production Cab #10
 
JJ 911SC's Avatar
 
Join Date: Jun 2009
Location: Ottawa, Ontario, Canada
Posts: 11,064
Garage
Porsche Crest

Quote:
Originally Posted by Christien View Post
... It's either fuel or spark you're missing, and checking to determine is fairly straightforward.
Unplug one of your spark plug, plug a good spark plug into the lead, ground it, have someone start the car and check for a spark.

This will either eliminate or point to an ignition problem.
__________________
Who Will Live... Will See

83 911 Production Cab #10, Slightly Modified: Unslanted, 3.2, PMO EFI, TECgt, CE 911 CAM Sync / Pulley / Wires, SSI, Dansk Sport 2/2, 17" Euromeister, CKO GT3 Seats, Going SOK Super Charger
Old 06-24-2010, 06:25 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
83 911 Production Cab #10
 
JJ 911SC's Avatar
 
Join Date: Jun 2009
Location: Ottawa, Ontario, Canada
Posts: 11,064
Garage
Porsche Crest and don't forget...

... to introduce yourself properly with photos.

Welcome to the board.

P.S. 3 Canucks replie in a row!!!
__________________
Who Will Live... Will See

83 911 Production Cab #10, Slightly Modified: Unslanted, 3.2, PMO EFI, TECgt, CE 911 CAM Sync / Pulley / Wires, SSI, Dansk Sport 2/2, 17" Euromeister, CKO GT3 Seats, Going SOK Super Charger
Old 06-24-2010, 06:28 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Nov 2008
Location: Crystal Lake, IL
Posts: 75
When you say no spark, have you pulled a plug and verified that it isn't sparking? Can you smell gas as it is cranking?
Agree with the above about the relay being a good place to start. Plus it is good to have one with you just in case you die by the side of the road.
If you have spark but no fuel check the fuel pump, jump the fuse for it to a live contact and verify that you can hear it spin up as a quick check. I just had to deal with one of them myself a month or so ago.

Welcome to the board and to beat the rush how about a pic of your ride so we can all drool.
__________________
88 Carrera Targa
04 Volvo XC-70
58 Harley Duo-Glide
96 BMW K-1100 LT
Old 06-24-2010, 06:31 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered
 
86 911 Targa's Avatar
 
Join Date: Jun 2009
Location: Manhattan Beach, California. Factory Delivery-Original owner-Retired engineer
Posts: 5,070
Quote:
Originally Posted by drisump View Post
i don't want to sound like a one hit wonder but an easy place to start is your dme relay located under your drivers seat. If you (or your cars previous owners), haven't already done this, it's time anyway (about $35). Cheers
+1

Also, perhaps the flywheel sensors?

Good luck,

Gerry
__________________
1986 911 Targa.
Per Road and Track magazine:
Only in L.A.:
In the window of a bar in Hermosa Beach, California.
"Happy Hour prices during all car chases."

Last edited by 86 911 Targa; 06-24-2010 at 10:25 AM..
Old 06-24-2010, 07:57 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered
 
scottb's Avatar
 
Join Date: Jul 2002
Location: Southern California
Posts: 5,038
Quote:
Originally Posted by Drisump View Post
I don't want to sound like a one hit wonder but an easy place to start is your DME relay located under your drivers seat. If you (or your cars previous owners), haven't already done this, it's time anyway (about $35). Cheers
I replaced mine before the old one failed, and then I tossed the old one into the glove box as a spare. Cheap insurance!
__________________
1984 Targa
Old 06-24-2010, 11:41 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered User
 
Join Date: Jun 2010
Location: Omaha
Posts: 7
Garage
I haven't had a chance to log on in few days. Thanks for the replies; I did pull a plug wire and grounded a new plug, had my wife turn it over, no spark. There is a fuel odor in the exhaust after turning over so I'm pretty sure it's an ignition problem. Sounds like a replacement DME relay is the best place to start.

Thanks again for the advice!!
Old 06-26-2010, 09:37 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered User
 
Hodgey's Avatar
 
Join Date: Dec 2009
Location: Kyle, TX
Posts: 591
Garage
JDale442

How you doooooin?????.....you just couldn't wait for me to get back to you could you mate?
Anyway, the relay is under the drivers seat as you originally thought.......just so you know!!!!

Stacey is the cutest troubleshooter you're ever gonna have Mr.........

BTW, my baby may be back with me this week....will send you pics!!!

Mill B'Stard
__________________
Neil

1987 Carrera, Grand Prix White, 2009 Carrera C4S, Meteor Grey Metallic
(X) [B] 2011 BMW X5[B]
'Success is not final, failure is not fatal. It is the courage to continue that counts'
Old 06-28-2010, 04:35 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registered User
 
Hodgey's Avatar
 
Join Date: Dec 2009
Location: Kyle, TX
Posts: 591
Garage
......oh and John........it's courtesy to post pictures of your little babies to introduce them to us all........
__________________
Neil

1987 Carrera, Grand Prix White, 2009 Carrera C4S, Meteor Grey Metallic
(X) [B] 2011 BMW X5[B]
'Success is not final, failure is not fatal. It is the courage to continue that counts'
Old 06-28-2010, 04:37 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered User
 
dsmithwc04's Avatar
 
Join Date: Jun 2010
Location: Indy
Posts: 107
Garage
I had the same problem. It was one of the red fuses (3rd or 4th from the left when facing the fuses) that had slipped out caused by the lead wire screws becoming loose. Check this and you may have a fix. Since you have a fuel smell probably not the fuel pump being stuck.
__________________
'82 911 SC track car - SOLD
'86 944 NA - SOLD
'01 Boxster S
Old 06-29-2010, 11:52 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
Registered User
 
Join Date: Jun 2010
Location: Omaha
Posts: 7
Garage
OK, I replaced the DME relay tonight, no change. I did notice that the tach stays on zero when cranking over. Any more ideas?
Old 07-02-2010, 08:53 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Registered User
 
Drisump's Avatar
 
Join Date: Sep 2009
Location: Galiano, BC
Posts: 1,404
Garage
Examine coil and power to it, lead from coil to distributor, cap and rotor..... other than those, it may be more involved....I'm not sure of all the conditions the DME needs to see before allowing power to go to the coil. If your starter is turning, you would think your engines grounding would be fine, but you should probably have a look. Sorry buddy, It is likely a very small issue, but I realize your 911 times a-wasting!
Old 07-02-2010, 10:11 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
83 911 Production Cab #10
 
JJ 911SC's Avatar
 
Join Date: Jun 2009
Location: Ottawa, Ontario, Canada
Posts: 11,064
Garage
Porsche Crest Been there...

Quote:
Originally Posted by jdale442 View Post
OK, I replaced the DME relay tonight, no change. I did notice that the tach stays on zero when cranking over. Any more ideas?
I had a similar problem and it turn out to be a broken (not blown) fuse in the engine compartment.

Before finding the actual problem, I end up putting 12 Volts (from the the rear fuse panel) directly to the coil and ran with that for a week.

Post pictures... of you car, it always help to get more help.
__________________
Who Will Live... Will See

83 911 Production Cab #10, Slightly Modified: Unslanted, 3.2, PMO EFI, TECgt, CE 911 CAM Sync / Pulley / Wires, SSI, Dansk Sport 2/2, 17" Euromeister, CKO GT3 Seats, Going SOK Super Charger

Last edited by JJ 911SC; 07-03-2010 at 02:39 AM..
Old 07-03-2010, 02:34 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
Registered
 
ischmitz's Avatar
 
Join Date: May 2002
Location: Santa Barbara, CA
Posts: 4,633
Garage
Send a message via Skype™ to ischmitz
jdale442,

if you get fuel but no spark you have effectively narrowed things down to the ignition system or maybe the flywheel sensors.

Make sure the coil shows +12V at both sides when the ignition is ON but you don't crank. This will rule out a fuse. check the resistance of the secondary with an Ohmmeter. Also verify the rotor and distributor are in good shape.

I suspect your DME could be damaged. When you crank the DME (not the DME relay) provides GND to one side of the coil for several milliseconds at a time. This generates the spark. You need an oscilloscope to verify this. I suggest you find a fellow Porsche owner close to you (where are you located?) who lets you swap your DME into his car or vise versa. Any 3.2 will do. This quickly tells you whether the DME is the culprit.

Ingo
__________________
'74 Targa 3.6 (not stock ) - '01 C4 (almost stock) - '00 ML430 (stock)

I repair/rebuild Bosch CDI Boxes and Porsche Motronic DMEs
Porsche "Hammer" or Porsche PST2 - I can help!!
How about a NoBadDays DualChip for 964 or '95 993
Old 07-03-2010, 06:11 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Registered User
 
Hodgey's Avatar
 
Join Date: Dec 2009
Location: Kyle, TX
Posts: 591
Garage
John

I think you can discount the fuel pump....this is from a post about a guy whose car wouldnt stay running when starting....


"First, the fuel pump is not supposed to run with the key to ON. It only runs when you crank or when the flywheel rotates with more than 200RPM. So no worries there."

Mill B'stard
__________________
Neil

1987 Carrera, Grand Prix White, 2009 Carrera C4S, Meteor Grey Metallic
(X) [B] 2011 BMW X5[B]
'Success is not final, failure is not fatal. It is the courage to continue that counts'
Old 07-04-2010, 09:34 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #17 (permalink)
Registered User
 
Join Date: Jun 2010
Location: Omaha
Posts: 7
Garage
Thanks for the info on the fuel pump Mr. Neil. I'm going to check the coil as suggested; sounds like with ignition on, either terminal should have 12V. to ground. Anybody know what the correct resistance should be on the secondary?
Old 07-05-2010, 09:17 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #18 (permalink)
Registered User
 
Join Date: Jun 2010
Location: Omaha
Posts: 7
Garage
OK, I checked the coil terminals with the ignition on, but not cranking over. I got a little over 12 volts on each terminal. I pulled the distributer cap, there was some minor corrosion but overall it looked really clean. I'm having some diffculty getting the cap back on, but i think it just takes patience.
Old 07-05-2010, 10:30 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #19 (permalink)
Registered User
 
Hodgey's Avatar
 
Join Date: Dec 2009
Location: Kyle, TX
Posts: 591
Garage
John
I should get my little baby back this week complete with Bentley Manual.
When I do, let's get to troubleshooting this thing and put it to bed!!!!!

M B

__________________
Neil

1987 Carrera, Grand Prix White, 2009 Carrera C4S, Meteor Grey Metallic
(X) [B] 2011 BMW X5[B]
'Success is not final, failure is not fatal. It is the courage to continue that counts'
Old 07-05-2010, 01:35 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #20 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 06:11 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2020 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.