[Miata] '93 Doesn't always start the first time

[James Thorusen]

Hi Brenda!

   In reading your post, I find that I have to infer some things.   Perhaps 
a clarification would be in order.   In order to troubleshoot a problem such 
as yours, we must differentiate between "won't start" and "won't crank". 
These are two entirely different things.

   Failure to start is an engine related problem... ignition, fuel 
injection, or even a broken timing belt.   Failure to crank is an electrical 
problem, limited to the battery, the starter, and the ignition switch in the 
order of most likelihood.

   I am assuming the latter.  Failure to crank must be isolated with a good 
voltmeter.   Because the places you have to measure are remote from the 
driver's position, a helper is required as well.

   First, get the thing to fail.   If it is starting normally, then you 
cannot locate the problem.   Once it has failed, have your helper hold the 
key in the cranking position while you measure the voltage on the main high 
current starter terminal.   If this voltage is about 11 volts or less, then 
you have a defective battery.

   (It is easiest to get at the starter electrical terminals through the 
passenger's side wheel well with the car on jackstands.   Remove the road 
wheel and tire.)

   (A quick check of battery condition can be made by turning on the cars 
headlights and observing them while your helper attempts to crank the car. 
The headlights should dim noticeably;  if they extinguish completely, or 
nearly so, then the battery is probably bad.)

   Assuming the battery is OK, next measure the voltage on the small push-on 
terminal that is the start control voltage to the solenoid.   If this is 11 
volts or less, look for problems with the ignition switch and associated 
wiring.

   If both of these voltages are OK and the car still will not crank, 
replace the starter.



Good Luck,
Jim T.
entropycat at verizon.net
'74   914
'90   Miata  (x3)

----- Original Message ----- 
From: "brenda batchelor" <alluvial at joimail.com>
To: <miata at realbig.com>
Sent: Wednesday, August 22, 2007 7:55 PM
Subject: [Miata] '93 Doesn't always start the first time


When it's warm outside, or I've driven a distance of say 50 miles or more, 
my 93 sometimes won't start.  I keep turning the key to the on position 
(sometimes 3 or 4 times) and it starts as usual.  Any ideas?