Club Cobra Keith Craft Motorsports  

Go Back   Club Cobra > Engine Building, Tuning, and Induction > Small Block Talk

Welcome to Club Cobra!  The World's largest non biased Shelby Cobra related site!

  •  » Representation from nearly all Cobra/Daytona/GT40 manufacturers
  •  » Help from all over the world for your questions
  •  » Build logs for you and all members
  •  » Blogs
  •  » Image Gallery
  •  » Many thousands of members and nearly 1 million posts! 

YES! I want to register an account for free right now!  p.s.: For registered members this ad will NOT show

MMG Superformance
Nevada Classics
MMG Superformance
Main Menu
Module Jump:
Nevada Classics
Nevada Classics
Keith Craft Racing
Advertise at CC
Banner Ad Rates
MMG Superformance
Keith Craft Racing
MMG Superformance
August 2018
S M T W T F S
      1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31  
  #1 (permalink)  
Old 08-05-2018, 05:17 AM
CC Member
Visit my Photo Gallery

 
Join Date: Jan 2009
Location: Harrison Twp, MI
Cobra Make, Engine: SPF Coupe #136, 427SR FI
Posts: 152
Not Ranked     
Default Car goes dead while driving but starts back up

Hey Gang,

Need some pointers on what possibly could be causing this problem and where to start looking.

I have a SPF Daytona Coupe with Roush 427sr and Mass-Flo Throttle Body FI (fox based ecu).

On the way home from a long flawless drive yesterday the motor died 4 times in about 10 miles. All about the same interval from each event.

Here's what would happen:
  • While driving the motor would die in an instant.
  • The tach plumeted immediately
  • No coughing...dead
  • All electrical was still functioning

Each time I would hit the starter and the motor would fire back up. I would say it took more cranks than usual and stumbled upon start.

BUT ...

Then would run fine for a few miles until it happened again.

When I got home I started/stopped the car a bunch of times each of which it started fine.

Here's what I have checked:
  • I can hear the electric fuel pump
  • The fuel pressure regulator shows the set pressure
  • No codes thrown from the ECU
  • While running I fiddled with the key to see if vibration would kill the motor - nope

Any thoughts on what this could be and what to check?

Thanks in advance!

Jeff
Reply With Quote
Sponsored Links
Sponsored Links
  #2 (permalink)  
Old 08-05-2018, 09:47 AM
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2007
Location: Colorado Springs, CO
Cobra Make, Engine: FFR, 427W, 8 Stack EFI
Posts: 1,973
Not Ranked     
Default

Usually when it just dies like that it's electrical. Probably ignition. Based on time interval, I would guess that something is getting hot, and getting ready to fail.
Probably not the coil, though. They usually don't fail like that.
__________________
.boB "Iron Man"
NASA Rocky Mountain TTU #42
www.RacingtheExocet.com
Reply With Quote
  #3 (permalink)  
Old 08-05-2018, 10:22 AM
CC Member
Visit my Photo Gallery

 
Join Date: Jan 2009
Location: Harrison Twp, MI
Cobra Make, Engine: SPF Coupe #136, 427SR FI
Posts: 152
Not Ranked     
Default

Quote:
Originally Posted by bobcowan View Post
Usually when it just dies like that it's electrical. Probably ignition. Based on time interval, I would guess that something is getting hot, and getting ready to fail.
Probably not the coil, though. They usually don't fail like that.
Bob - I think you nailed it when you said...looks like something is getting ready to die...

So this morning I pull the car out, check all connections and decided to start and then move wires, connections looking for an issue.

It started and before I could crawl out of the car it died. This time permanently. Would not restart. The ECU light on the dash that illuminates when the key is on indicating the ECU is working is not illuminating.

So I think it is the ECU that failed.

Thanks for the input.

Jeff
Reply With Quote
  #4 (permalink)  
Old 08-05-2018, 10:26 AM
twobjshelbys's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jan 2009
Location: Las Vegas, NV
Cobra Make, Engine: Shelby CSX4005LA, Roush 427IR
Posts: 3,210
Not Ranked     
Default

Check ground esp on fuel pump. If you have a fuel cutoff switch make sure it is ok. My Lucas switch depends developed a flat spot that tripped on bumps and killed the car on the freeway. I jammed a toothpick to keep it away from the trouble spot
__________________
Cheers,
Tony
CSX4005LA
Reply With Quote
  #5 (permalink)  
Old 08-05-2018, 11:02 AM
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2007
Location: Colorado Springs, CO
Cobra Make, Engine: FFR, 427W, 8 Stack EFI
Posts: 1,973
Not Ranked     
Default

Quote:
Originally Posted by jeffgrice View Post

So I think it is the ECU that failed.

Thanks for the input.

Jeff
Do you have a relay for the ECU? I would check that first. Make sure the ECU is getting power. ECU's almost never fail - sometimes, but it's rare. Relays, fuses, fusable links, etc, often fail.
__________________
.boB "Iron Man"
NASA Rocky Mountain TTU #42
www.RacingtheExocet.com
Reply With Quote
  #6 (permalink)  
Old 08-05-2018, 05:41 PM
520SC's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2017
Location: Ewa Beach, HI
Cobra Make, Engine: 1966 Street Beasts Cobra 427 S/C, 502 cid
Posts: 110
Not Ranked     
Default

The fact that the ECU throws no code when the engine dies points to loss of power to the ECU. There's no code for that. So, there's a good chance you have a loose power connection to the ECU.
__________________
Todd
Reply With Quote
  #7 (permalink)  
Old 08-09-2018, 08:07 PM
CC Member
Visit my Photo Gallery

 
Join Date: Aug 2006
Location: Jacksonville, Fl
Cobra Make, Engine: Just a collection of parts right now...
Posts: 273
Send a message via MSN to spl310
Not Ranked     
Default

Are you by chance running an MSD unit?
Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 06:32 PM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: CC Policy
Links monetized by VigLink