[DeTomaso] sparkless cat

[Doug Braun]

Rolf,

I'd get the car to the point where it won't start and then do the following
tests:

1) Turn the key on.
2) Verify with a voltmeter that you have 10 to 12V at the coil's positive
terminal (If not, you have a wiring or ignition switch problem).
If you have the proper voltage then proceed to the next step.

Test your coil as follows:
1) Turn the key off.
2) Disconnect (from the coil) the wire the runs from the distributor to the
negative terminal of the coil.
3) Connect a spare wire to the negative terminal of the coil (the other end
of the spare wire must be able to reach a ground point on the engine, such
as an intake bolt).
4) Disconnect the high-tension coil wire from the center of the distributor
cap and connect the open end of the high tension wire to a spare spark plug.
5) Hold the threads of the spark plug against an intake bolt head.
6) Turn the key "ON".
7) Now, touch the open end of the spare wire to an intake bolt and then
remove it.  Whenever you remove the wire end from the bolt head, the spark
plug should spark.
If it doesn't spark,you have a bad coil.

If the coil tests out OK, then test the distributor as outlined here:
http://www.malloryperformance.com/pdf/UniliteTest.pdf.

Remember, in order to locate the problem, you must perform these tests when
the system has failed, not when it's working,


Doug Braun
blue 73L #5505
  -----Original Message-----
  From: Rolf Poulsen [mailto:rolf_poulsen at hotmail.com]
  Sent: Thursday, July 23, 2009 9:54 AM
  To: doug at silicondesigns.com
  Subject: RE: [DeTomaso] sparkless cat


  Thanks for the reply.
  I have a Mallory Unilite distributor part no. 4756701. I'll take my
voltmeter and see if there goes any current into the coil. Do you know if
there goes current to the coil with the key turned (but without cranking the
engine)

  Rolf

  > From: doug at silicondesigns.com
  > To: rolf_poulsen at hotmail.com
  > Subject: RE: [DeTomaso] sparkless cat
  > Date: Thu, 23 Jul 2009 08:25:10 -0700
  >
  > Rolf,
  >
  > Did someone answer you on this? If not, do you have a points type
  > distributor or an electronic one? If it's an electronic type, what brand
is
  > it? Do you have a capacitive discharge type of ignition? and if so what
  > brand.
  >
  > Doug Braun
  >
  > -----Original Message-----
  > From: detomaso-bounces at realbig.com
  > [mailto:detomaso-bounces at realbig.com]On Behalf Of Rolf Poulsen
  > Sent: Wednesday, July 22, 2009 2:55 PM
  > To: detomaso at realbig.com
  > Subject: [DeTomaso] sparkless cat
  >
  > Yesterday when I startede the car backed it out of the garage,
  >
  > while idling the car died like it normally does the first 2 minutes
before
  > the warmes up.
  >
  > But this time it wouldnt start, today it check the sparkplugs and there
was
  > no spark.
  >
  > I suspect it could be the ignition coil (mallory promaster) how do I
start
  > troubleshoot?