• Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech

67 EFI conversion... no fire

  • Thread starter Thread starter Red5oh
  • Start date Start date Sep 5, 2005
R

Red5oh

Member
Jul 8, 2005
377
0
17
DFW, Texas
Sep 5, 2005
#1
  • Sep 5, 2005
  • #1
I am ready to start this thing and now no fire.... UGH!

Anyway, its a windsor fox harness, and I have found out a day late and a dollar short, that they are IMPOSSIBLE to get ahold of.

So.. I need help. Is there any diagnostics to run to see why no fire. There is fuel pressure and the distributor came out of a running car. The coil is questionable, but I removed it from a running car a LONG time ago.

On the TFI module, I have 12V on 2 and 3 on 'run' and 12V on 3 and 4 on 'start'

Is there anything else that would cause it not to fire. I guess the TFI module could have gone bad, but I wouldnt suspect that from just sitting.

Any help, as this thing is ready to live!

There is no popping, no nothing... I put a spark plug tester on the coil lead and I get ONE spark when you release the key from the 'start' position. It does this everytime.

Thanks in advance for the help.
 
J

JB66

New Member
Aug 21, 2004
565
1
0
New York
Sep 5, 2005
#2
  • Sep 5, 2005
  • #2
The system will always spark once when you turn it on or off. Check the Hall efffect vane and trigger coil inside the dist. and for the little expense, replace the TFI. They go bad faster than candy melts in the sun.
 
M

mustangracer

Founding Member
Jun 15, 1999
360
0
0
Southern California
Sep 6, 2005
#3
  • Sep 6, 2005
  • #3
I had the same problem initally (exact same symptoms also), turns out I had forgotten there are two different paths for coil voltage. One is from the ignition switch proper when the switch is in the RUN position. The other is via the starter solenoid I terminal when the switch is in the START position. One way to check is to run a hot lead from the battery + to the coil (bat or + terminal), and crank the car, if it starts, it means there is a problem with the voltage to the coil. Be warned it won't shut off when you turn off the key, you'll have to pull the hot wire.
 
R

Red5oh

Member
Jul 8, 2005
377
0
17
DFW, Texas
Sep 6, 2005
#4
  • Sep 6, 2005
  • #4
I will test for that tonight. I did check the coil voltage when in the RUN position and it did have voltage. That makes sense.

If that is it, then I will have to find a START position to power the coil from?

I will let you know what I find out.

Thanks, Mark
 
R

Red5oh

Member
Jul 8, 2005
377
0
17
DFW, Texas
Sep 6, 2005
#5
  • Sep 6, 2005
  • #5
Ok, that was it. I ran a jumper wire from the battery to the coil, and when it is connected, it ran the fuel pump etc. Engine fired right off. Of course, I had to remove the wire to kill it.

So, on the newer starter solenoid, do I run the coil wire to the 'starter' side of the solenoid, so it gets power while cranking? What did you do?

Thanks, Mark
 

67coupe351w

New Member
Jan 31, 2004
424
0
0
Portland, OR
Sep 6, 2005
#6
  • Sep 6, 2005
  • #6
Red5oh said:
Ok, that was it. I ran a jumper wire from the battery to the coil, and when it is connected, it ran the fuel pump etc. Engine fired right off. Of course, I had to remove the wire to kill it.

So, on the newer starter solenoid, do I run the coil wire to the 'starter' side of the solenoid, so it gets power while cranking? What did you do?

Thanks, Mark
Click to expand...

The other small post labeled "S" on the solenoid is for supplying power to the coil durring cranking I believe.
 
M

mustangracer

Founding Member
Jun 15, 1999
360
0
0
Southern California
Sep 7, 2005
#7
  • Sep 7, 2005
  • #7
The S terminal is the crank input from the ignition switch, the I terminal is the crank position coil voltage source. Put a voltmeter on the I terminal and you should see 12V when cranking. Run this to the coil + terminal. I integrated a '92 harness with the stock 65 engine harness, and used a relay to provide switched 12v to the ignition versus running it all through the ignition switch.
 
R

Red5oh

Member
Jul 8, 2005
377
0
17
DFW, Texas
Sep 7, 2005
#8
  • Sep 7, 2005
  • #8
I am not using the 67 starter solenoid, but the 91 version. It only has one terminal on it. Basically, the start (or engage) terminal.

The strange thing is that the TFI is seeing the START signal coming from the ignition switch, and the TFI power is on during RUN and START. That is supposed to be the power to the coil during the same time.

I know I could 'make it work' but this harness was supposed to make it right.

Could a coil that is marginal cause too much voltage loss during the START cycle and bring down the voltage to 0V? But, when I hooked it up directly to the battery, the coil worked fine.

Anyway, tonight I will check the wiring connection to the EFI harness for the power to/from the ignition switch.

Thanks for the help and I will let you know. Mark
 
J

JB66

New Member
Aug 21, 2004
565
1
0
New York
Sep 7, 2005
#9
  • Sep 7, 2005
  • #9
I would try one of the late model coils and see if that works. The TFI probably doesn't provide enough amperage or duration to allow the old style coils to build up voltage enough to fire.
 
R

Red5oh

Member
Jul 8, 2005
377
0
17
DFW, Texas
Sep 7, 2005
#10
  • Sep 7, 2005
  • #10
Sorry for not clarifying... I am using the 91 TFI coil as well.
Thanks for the suggestion.
 
R

Red5oh

Member
Jul 8, 2005
377
0
17
DFW, Texas
Sep 7, 2005
#11
  • Sep 7, 2005
  • #11
I replaced the ignition switch and it started right up. Sounds great!!!!

I started/restarted it too many times and I think I flooded it (I dont have a throttle cable on it yet) so it will have to sit a bit... I am sure it will start right up.

Now all I have to do is finish the rest of the car.

Thanks for all the help.

Mark
 

monk302

Founding Member
Apr 18, 2001
742
2
16
New Jersey
Aug 15, 2006
#12
  • Aug 15, 2006
  • #12
About finished with EFI. Now it won't start?!

So I have my car all set up and ready to go with the EFI. So now it cranks, there is fuel, but I cannot get it to start. One thing that did happen was that there was some sort of backfire that came through the air filter. Made quite a popping noise and a small amount of smoke. So now I would like to get this thing running but I am not sure what is wrong. How can I test for spark? What would cause the backfire through the air filter? Any suggestions?
 
R

Red5oh

Member
Jul 8, 2005
377
0
17
DFW, Texas
Aug 16, 2006
#13
  • Aug 16, 2006
  • #13
Check timing.... Mine occasionally backfires through the throttle body and it was not getting fire during the 'crank' cycle. It was getting it when in 'run'. The ignition switch took care of my problems.
 

monk302

Founding Member
Apr 18, 2001
742
2
16
New Jersey
Aug 16, 2006
#14
  • Aug 16, 2006
  • #14
Do you mean the ignition switch in the dash? The one you put the key into?
 
R

Red5oh

Member
Jul 8, 2005
377
0
17
DFW, Texas
Aug 16, 2006
#15
  • Aug 16, 2006
  • #15
Yes, the key switch
 
You must log in or register to reply here.

Similar threads

8
Electrical Crank-no start ... no spark ... no injector pulse, was it something I did? (redux)
  • 85gtCOBRA
  • Oct 28, 2025
  • Fox 5.0 Mustang Tech
Replies
2
Views
491
Fox 5.0 Mustang Tech Oct 29, 2025
85gtCOBRA
8
B
No spark. 1990 foxbody 5.0 gt
  • Boogi
  • Nov 16, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
0
Views
163
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Nov 16, 2025
Boogi
B
9
1995 5.0 just cranks
  • 9GT5
  • Jun 29, 2025
  • 1994 - 1995 Specific Tech
Replies
1
Views
339
1994 - 1995 Specific Tech Jun 29, 2025
AeroCoupe
A
Check Engine codes jumping around
  • azactor
  • Jan 9, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
1
Views
161
1996 - 2004 SN95 Mustang -General/Talk- Jan 10, 2026
gkomo
T
Help with a 95 5L crank no start
  • TheBubbaJoe
  • Nov 4, 2025
  • 1994 - 1995 Specific Tech
Replies
3
Views
394
1994 - 1995 Specific Tech Nov 5, 2025
AeroCoupe
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?