A car starting infrequently when the key is turned could be caused by a number of things. Here's where to look.

Dear Car Talk | Oct 01, 1997
Dear Tom and Ray:
think either has an electrical short or a key that isn't working properly.
Sometimes, I turn the key in the ignition and ... nothing. Sometimes it does
this two or three times and then starts. Then it can go a month without doing
it.
It seems to be happening more frequently now, and I would like to get it fixed
before I get stranded. My battery's good, and the cables are not corroded. --
Diane
RAY: We'll use the scientific method to get at this answer, Diane -- the same
thoughtful approach that led us to conclude that the majority of gum-chewing,
Camaro and Firebird owners with teased hair are named Donna.
TOM: We'll begin by testing the starter. Ask your mechanic to check if current
is getting to the starter solenoid (SEW-luh-noid) when your car won't start.
RAY: If he doesn't have the patience to keep trying it all day until the
problem occurs for him, ask him to hook up a test light so you can see it in
the passenger compartment. Then, drive around. And next time the car won't
start, you can see for yourself if the light comes on (that would mean there
IS current at the starter), and report back to him.
TOM: If current IS getting to the starter, then you know the starter is going
bad, and you can replace it, and all your problems will be solved (except what
to do with that ugly test light your mechanic installed in your passenger
compartment).
RAY: If there's no current getting to the starter, you have to work your way
backward. Next I'd ask the mechanic to replace your Neutral safety switch --
assuming the Camaro has an automatic transmission. That switch prevents you
from starting the car in any gears but Park and Neutral, so you don't start in
Drive and crash through your mother-in-law's garage door. When a Neutral
safety switch goes bad, it can prevent you from starting the car in ANY gear.
So I'd put in a new one and see if the problem goes away.
TOM: A lot of stick-shift cars have a similar device called a "clutch
interlock," which prevents you from starting the car unless the clutch is
fully depressed. And that can cause similar problems.
RAY: If the problem is still there after your car passes the other tests, then
I'd strongly suspect the ignition switch. Ignition switches are like that.
They go bad by failing some of the time ... then they fail more of the time
... then most of the time ... then all of the time.
TOM: Kind of like the strategy my brother employed during his eight-year
college career.
* * *
If you want to ruin your car, we have 10 ways for you to do it. If you don't
want to ruin your car, we have "Ten Ways You May Be Ruining Your Car Without
Even Knowing It!" You can order the booklet by sending $3 and a
self-addressed, stamped (55 cents) No. 10 envelope to Ruin No. 1, P.O. Box
6420, Riverton, NJ 08077-6420.
think either has an electrical short or a key that isn't working properly.
Sometimes, I turn the key in the ignition and ... nothing. Sometimes it does
this two or three times and then starts. Then it can go a month without doing
it.
It seems to be happening more frequently now, and I would like to get it fixed
before I get stranded. My battery's good, and the cables are not corroded. --
Diane
RAY: We'll use the scientific method to get at this answer, Diane -- the same
thoughtful approach that led us to conclude that the majority of gum-chewing,
Camaro and Firebird owners with teased hair are named Donna.
TOM: We'll begin by testing the starter. Ask your mechanic to check if current
is getting to the starter solenoid (SEW-luh-noid) when your car won't start.
RAY: If he doesn't have the patience to keep trying it all day until the
problem occurs for him, ask him to hook up a test light so you can see it in
the passenger compartment. Then, drive around. And next time the car won't
start, you can see for yourself if the light comes on (that would mean there
IS current at the starter), and report back to him.
TOM: If current IS getting to the starter, then you know the starter is going
bad, and you can replace it, and all your problems will be solved (except what
to do with that ugly test light your mechanic installed in your passenger
compartment).
RAY: If there's no current getting to the starter, you have to work your way
backward. Next I'd ask the mechanic to replace your Neutral safety switch --
assuming the Camaro has an automatic transmission. That switch prevents you
from starting the car in any gears but Park and Neutral, so you don't start in
Drive and crash through your mother-in-law's garage door. When a Neutral
safety switch goes bad, it can prevent you from starting the car in ANY gear.
So I'd put in a new one and see if the problem goes away.
TOM: A lot of stick-shift cars have a similar device called a "clutch
interlock," which prevents you from starting the car unless the clutch is
fully depressed. And that can cause similar problems.
RAY: If the problem is still there after your car passes the other tests, then
I'd strongly suspect the ignition switch. Ignition switches are like that.
They go bad by failing some of the time ... then they fail more of the time
... then most of the time ... then all of the time.
TOM: Kind of like the strategy my brother employed during his eight-year
college career.
* * *
If you want to ruin your car, we have 10 ways for you to do it. If you don't
want to ruin your car, we have "Ten Ways You May Be Ruining Your Car Without
Even Knowing It!" You can order the booklet by sending $3 and a
self-addressed, stamped (55 cents) No. 10 envelope to Ruin No. 1, P.O. Box
6420, Riverton, NJ 08077-6420.
Got a question about your car?