Club Cobra

Club Cobra (http://www.clubcobra.com/forums/)
-   Classic Roadsters II (http://www.clubcobra.com/forums/classic-roadsters-ii/)
-   -   Wring - Engine Stopped suddenly (http://www.clubcobra.com/forums/classic-roadsters-ii/142794-wring-engine-stopped-suddenly.html)

Manx69 09-18-2019 12:19 PM

Wring - Engine Stopped suddenly
 
I have a CR Sebring: Ford 5.0 HO 9189 fuel injected and stock, 5-speed, 8.8 4-link rear. the engine just dies suddenly while diving in 4th gear at about 50 mph. This car has the GM steering column and ignition switches, fuse panel by driver's left knee. Here's what I know:
I replaced the TFI ignition module . wasted $60, should have done proper troubleshooting.
Engine cranks over nicely.
There is no voltage (actually 0.6 VDC) to ignition coil or EEC relay.
all other electrical components work perfect: fuel pump, lights, horn, flashers, etc. Amp light comes on and amp meter on dash reads strong voltage but less than 12 (~11.5). DVM measures 12.5 VDC at battery.
The "gost" voltage (0.6 VDC) at coil and EEC relay are the same so i think there is continuity between them.
So, seems to me that somewhere between the ignition switch and the coil there is a break in the circuit.
The build manual I have does not seem to match my car so I don't know how the output from the ignition switch goes to the coil. The engine wiring harness seems correct for the engine with all wires colored as in the ford harness.
Any ideas?
Does anyone have a build manual with wiring diagram/instructions for a CR Cobra or Sebring from that era - 1989?
Thanks.
Keith

HighPlainsDrifter 09-18-2019 02:20 PM

Check if you have 12 v at the coil with key on. A coil needs 12v constant on positive side and an interrupted on- off ground to fire.
Perry

Manx69 09-18-2019 07:58 PM

Thank you.
There is no voltage to coil nor the relay that activates the computer. Ford wiring harness shows that as a single circuit directly off of the ignition switch with a fusible link in the line.
I don’t know where to start looking for the problem but it clearly resides between the ignition switch and coil. I just don’t know how to locate where and follow that wire.

HighPlainsDrifter 09-18-2019 09:41 PM

fuse link
 
Hi,
the fuse link is a 10 ga wire from the starter solenoid, yellow probably. you can check there for 12 v but will probably have to cut and replace that fuse link at the starter solenoid.(disconnect battery 1st)
"The ignition switch gets power from the two yellow wires that are supplied power by a fuse link located in the wiring harness that connects to the starter solenoid."
Perry.:MECOOL:

Cruisin428 09-19-2019 03:13 AM

Pull the eec relay (also, disconect the coil wire from the coil), check for 12v coming to the relay, jumper a wire across and check 12v past it at the eec (might want to disconect the eec. Having a loose ground , loose 12v, corrosion in a wire or at a plug or a relay that has burnt contacts could give you a low voltage

Also, With the power OFF, use your OHMs setting on the meter and check continuity of the wire itself from one end to other. Set it to the diode setting if you have it, and the meter will give you a strong beep?? Sound if you have continuity. You may have to disconect the wires from where they go! As in pulling the eec or its relay, disconect the coil wire from the coil etc. this will also check the fuse links (just noticed you stated 0 v at the eec and coil and i am not looking at a wiring diagram at the moment, so parts of the above it seems you already know!)
You could jumper 12v to the eec relay and see if you have 12 v at the coil then you know its a wire under the dash and not engine compartment for the coil!

Manx69 09-19-2019 02:44 PM

Thanks for some great advice. Pretty much where i was going next. I'll let you now how it turns out.

twobjshelbys 09-19-2019 05:13 PM

Quote:

Originally Posted by HighPlainsDrifter (Post 1466832)
Check if you have 12 v at the coil with key on. A coil needs 12v constant on positive side and an interrupted on- off ground to fire.
Perry

Alot of this is not correct if you have a capactive discharge electronic ignition, like a MSD box. If you do check the book on how to measure spark.

Gaz64 09-20-2019 05:10 AM

Quote:

Originally Posted by twobjshelbys (Post 1466862)
Alot of this is not correct if you have a capactive discharge electronic ignition, like a MSD box. If you do check the book on how to measure spark.

Keith's specs seem unlikely to have MSD CDI ignition, so Perrys statement of 12v on the coil positive, and interrupted ground on coil negative would be true in this case. Normal for any inductive spark ignition.

Gary

HighPlainsDrifter 09-20-2019 08:02 AM

MSD not all that reliable?
 
Hi,
3 cobras going north out of Reno in the middle of nowhere...…….
the leader Fred's cobra backfires and dies, coasts to a stop on 2 lane road:eek:
I pull out my meter and check things. 3rd cobra goes back to Reno 45 miles to summit racing and gets another msd box while Fred and I take out his existing box, no small feat at side of road. 3 hours later back on the road. His msd probably died from the heat in his engine bay. I also ran an msd but it was mounted in the passenger foot box and never had a problem with it. Just one story of the 55,000 miles I put on my 1st cobra:cool:
Perry.

cycleguy55 09-20-2019 11:23 AM

Ford EEC-IV/TFI-IV Electronic Engine Control Troubleshooting
https://therangerstation.com/tech_li...agnostic.shtml

Fords Without a Check Engine Light
  1. Start the vehicle and let the engine warm. Then, turn the engine off. [Note: yes, I'm aware the car won't run. Obviously you will have to skip this step.]
  2. Set the volt meter to read between 0 and 15 DC volts. Connect your volt meter's positive lead to the postive terminal on the Ford's battery. Then, connect negative lead to the self test outlet's grounding slot.
  3. Connect the self test outlet's signal return slot to the self test input with a jumper wire.
  4. Turn the Ford "On," but do not start the engine. Count the times the needle sweeps. There will be a small pause between numbers within the code. Code 14, for example, will have one needle sweep, followed by a pause and then four more needle sweeps. Long pauses indicate the beginning and end of a new trouble code.
http://diagnosecarproblems.blogspot....rd-eec-iv.html

Manx69 09-27-2019 10:51 PM

So here’s the story. There is a circuit board on which are mounted all of the fuses and some relays. The terminal at the top fuse is where a black wire goes to the red and green wire in the engine wiring harness. The terminal failed. The next fused terminal below it was also switched off of the ignition and empty. Simply moved the wire and fuse down to that terminal. I have no clue as to what caused the failure.

I verified power through the ignition switch but was not sure which specific wire went to the coil and relay wire in the engine harness. Found it after lots of continuity checks in various parts of the under-hood and under-dash rats nests until I located it and traced it back to the circuit board. This was a very miserable and time consuming job. Many hours of uncomfortable troubleshooting and the such a simple fix. All is now well. Thanks to all who gave advice.


All times are GMT -7. The time now is 08:46 PM.

Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2024, 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: