[DeTomaso] Techno question: it is the starter gremlin again

[Doug Braun]

Chuck,

	I've found that this type of problem is best attacked by two people with a
voltmeter and an extended ground lead for the voltmeter.  Get your car hot
so the problem will arise and then strategically measure the voltage drops
in the starter system while cranking (this is why two people are needed).
Begin by measuring the voltage during hot start between the negative battery
post and the lower starter mounting stud while cranking.  Then do the same
test between the positive battery post and the positive post at the starter.
Ideally you should see similar (far less than a volt) readings for each
test.  If one reading is far larger than the other, then concentrate on
improving that section of connections.  15 years ago, my hot start problem
was due to a poor ground connection through the ZF to the starter (see #14
below).  By adding a second ground cable from a bell housing bolt to an
engine mount bolt at the frame, the problem was solved.  Voltage drops can
occur at any or all of the following places.  By moving your voltmeter along
each run and testing these connections, cables and components, you can
pinpoint the areas of greatest voltage loss.  In other words, these
measurements will tell you where the problem is.

1. Positive battery post -to- Positive battery cable clamp at battery
(connection test).
2. Positive battery cable clamp at battery -to- Positive battery cable's
ring tongue terminal at solenoid (cable test).
3. Positive battery cable's ring tongue terminal at solenoid -to- Solenoid's
battery side stud (connection test).
4. Solenoid's battery side stud -to- Solenoid's starter side stud (solenoid
test).
5. Solenoid's starter side stud -to- Starter cable's ring tongue terminal at
solenoid (connection test).
6. Starter cable's ring tongue terminal at solenoid -to- Starter cable's
ring tongue terminal at starter (cable test).
7. Starter cable's ring tongue terminal at starter -to- Starter's positive
stud (connection test).

8. Negative battery post -to- Negative battery cable clamp at battery
(connection test).
9. Negative battery cable clamp at battery -to- Negative battery cable's
ring tongue terminal at front trunk ground stud (cable test).
10. Negative battery cable's ring tongue terminal at front trunk ground
stud -to- Front trunk ground stud (connection test).
11. Front trunk ground stud -to- Engine bay ground stud behind transaxle
(frame conduction test).
12. Engine bay ground stud behind transaxle -to- Transaxle ground cable's
ring tongue terminal at engine bay stud (connection test).
13. Transaxle ground cable's ring tongue terminal at engine bay stud -to-
Transaxle ground cable's ring tongue terminal at transaxle stud (cable
test).
14. Transaxle ground cable's ring tongue terminal at transaxle stud -to-
starter mounting stud (transaxle conduction test).
15. Starter mounting stud -to- Starter case. (starter conduction test).

Good luck

Doug Braun
blue 73L #5505


-----Original Message-----
From: detomaso-bounces at realbig.com
[mailto:detomaso-bounces at realbig.com]On Behalf Of Charles Engles
Sent: Wednesday, July 08, 2009 8:20 PM
To: detomaso at realbig.com
Subject: [DeTomaso] Techno question: it is the starter gremlin again


Dear Forum,


     It is the hot start problem with the starter again.   The old starter
is about ten years old.  It starts cold fine, but wheezes and starts
theatrically very slowly when it the engine is up to running temperature.
It was marginally better by adding a second ground cable.

     I decided to install the $50 DB starter.   It starts right up cold, but
acts the same way as the old starter.

     This obviously means the problem ain't the starter.  So..... the
gremlin lies in the ground ????---------or the gremlin needs a larger power
cable to the starter????

                         Warmest regards,  Chuck Engles