car only startes sometimes
Thread Starter
Instructor
Joined: Mar 2004
Posts: 141
Likes: 0
From: Burbank IL
car only startes sometimes
hi i have a 90 that only turns over sometimes i got the starter rebuilt and it still does the same thing. does anyone know how to test the starter or selenoid while its on the car.
thanks mike
thanks mike
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
If the starter is ok, I would check the battery and the cables.
Corrosion can (and does) work its way up the various connections and will increase resistance to epic levels.
I would clean the battery and starter terminals.
Corrosion can (and does) work its way up the various connections and will increase resistance to epic levels.
I would clean the battery and starter terminals.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
You can jump 12v to one terminal of the clutch safety switch (gear selector switch if automatic) to test your starter, it should crank. It is important to have clean tight connections of the battery cables to the battery terminals in order to supply the 100+ amps starters require.
You might have VATS problems. Contacts in your ign tumbler make connection to your key pellet and the VATS module measures the resistance of the pellet and if correct, it closes the start enable relay which passes 12v from the ign sw through the relay through the clutch safety switch and to the starter solenoid on the starter. When it won't crank, wait 6 minutes as the ECM won't allow a crank for 6 minutes when it doesn't see the correct resistance and after several tries. First try your spare ign key as its pellet contacts aren't worn like your everyday key. Next jump the clutch safety switch and try a crank. If no crank remove the hush panel above the drivers feet and locate the two wires from the steering column that go to a 2 pin connector (pellet tumbler contacts). Unplug the connector, insert your ign key and measure the resistance across the wires from the steering column, it should measure the same as your pellet. If over 13k ohms, you need an ign tumbler which has new contacts. You can temporarily bypass VATS by clipping a 5 % 1/4 watt or higher power resistor the same resistance value as your pellet across the wires going into the wiring harness (VATS module). You can use a resistor from Radio Shack. Don't permanently bypass VATS as 99% of thefts are done by bashing the column and jumping the ignition. I am assuming 90's VATS are the same as my 87.
You might have VATS problems. Contacts in your ign tumbler make connection to your key pellet and the VATS module measures the resistance of the pellet and if correct, it closes the start enable relay which passes 12v from the ign sw through the relay through the clutch safety switch and to the starter solenoid on the starter. When it won't crank, wait 6 minutes as the ECM won't allow a crank for 6 minutes when it doesn't see the correct resistance and after several tries. First try your spare ign key as its pellet contacts aren't worn like your everyday key. Next jump the clutch safety switch and try a crank. If no crank remove the hush panel above the drivers feet and locate the two wires from the steering column that go to a 2 pin connector (pellet tumbler contacts). Unplug the connector, insert your ign key and measure the resistance across the wires from the steering column, it should measure the same as your pellet. If over 13k ohms, you need an ign tumbler which has new contacts. You can temporarily bypass VATS by clipping a 5 % 1/4 watt or higher power resistor the same resistance value as your pellet across the wires going into the wiring harness (VATS module). You can use a resistor from Radio Shack. Don't permanently bypass VATS as 99% of thefts are done by bashing the column and jumping the ignition. I am assuming 90's VATS are the same as my 87.
Le Mans Master
Joined: Dec 2002
Posts: 6,715
Likes: 2
From: Santa Teresa New Mexico
Originally Posted by jfb
You can jump 12v to one terminal of the clutch safety switch (gear selector switch if automatic) to test your starter, it should crank. It is important to have clean tight connections of the battery cables to the battery terminals in order to supply the 100+ amps starters require.
You might have VATS problems. Contacts in your ign tumbler make connection to your key pellet and the VATS module measures the resistance of the pellet and if correct, it closes the start enable relay which passes 12v from the ign sw through the relay through the clutch safety switch and to the starter solenoid on the starter. When it won't crank, wait 6 minutes as the ECM won't allow a crank for 6 minutes when it doesn't see the correct resistance and after several tries. First try your spare ign key as its pellet contacts aren't worn like your everyday key. Next jump the clutch safety switch and try a crank. If no crank remove the hush panel above the drivers feet and locate the two wires from the steering column that go to a 2 pin connector (pellet tumbler contacts). Unplug the connector, insert your ign key and measure the resistance across the wires from the steering column, it should measure the same as your pellet. If over 13k ohms, you need an ign tumbler which has new contacts. You can temporarily bypass VATS by clipping a 5 % 1/4 watt or higher power resistor the same resistance value as your pellet across the wires going into the wiring harness (VATS module). You can use a resistor from Radio Shack. Don't permanently bypass VATS as 99% of thefts are done by bashing the column and jumping the ignition. I am assuming 90's VATS are the same as my 87.
You might have VATS problems. Contacts in your ign tumbler make connection to your key pellet and the VATS module measures the resistance of the pellet and if correct, it closes the start enable relay which passes 12v from the ign sw through the relay through the clutch safety switch and to the starter solenoid on the starter. When it won't crank, wait 6 minutes as the ECM won't allow a crank for 6 minutes when it doesn't see the correct resistance and after several tries. First try your spare ign key as its pellet contacts aren't worn like your everyday key. Next jump the clutch safety switch and try a crank. If no crank remove the hush panel above the drivers feet and locate the two wires from the steering column that go to a 2 pin connector (pellet tumbler contacts). Unplug the connector, insert your ign key and measure the resistance across the wires from the steering column, it should measure the same as your pellet. If over 13k ohms, you need an ign tumbler which has new contacts. You can temporarily bypass VATS by clipping a 5 % 1/4 watt or higher power resistor the same resistance value as your pellet across the wires going into the wiring harness (VATS module). You can use a resistor from Radio Shack. Don't permanently bypass VATS as 99% of thefts are done by bashing the column and jumping the ignition. I am assuming 90's VATS are the same as my 87.
Not many have that kind of expertise.
Most don't have a multi-meter let alone any knowledge on how to use it.
On the VATS is a bad design that only gets worse with age.
By-passing it doesn't take any expertise and it can be done with a kit.
As far as theft goes thats what insurance is for and Corvettes are way down on the steal me list. Japanese imports are on the top.
Plus and this is a real plus insurance compaines pay full dollar if your car is stolen. That is if you can prove you didn't leave the keys in it.
