My car wont start
a) Do you have crank no start? (see entire write up)
b)No crank no start ,No dash lights?, ( battery, battery cables, ignition switch,,starter relay)
If you have symptom A then the affected items are , ignition switch, battery, battery cables, starter, starter relay ,coil, coil pack, ignition module ,Distributor cap ,rotor, (if applicable) spark plugs and wires.
The best thing to do is to first make sure your timing belt didn't break. As long as the engine cranks you can do this. Give the battery a 3 min charge . Then have a helper crank the vehicle while you observe the rotation of all the pulley's and belts. They must rotate together. If the vehicle has a distributor remove the cap, ground the coil wire and remove fuel pump relay ( to disconnect the pump for testing)and watch the rotor as the engine is cranked. it should spin. If this is a-ok your worse nightmare is over.
Now we have eliminated the timing belt as being a cause. We now have to charged the battery again for three min and load test it( this is best done by a repair shop a load tester is expensive .If the battery if more than 5yrs old you may want to replace it.
If battery does not pass load test replace it.
Whatever you decide the rest of the items can NOT be checked out without a fully charged battery.
Check ignition switch and starter relay for B+ going to them and leaving them. Check starter circuit. Make sure B+ is making it to starter ( use a digital voltmeter). If B+ (12 volts) is making it to the starter and it doesn't crank then the starter is defective. Verify this by removing the starter and have it bench tested.
If starter cranks now your into coil testing . First thing reconnect the distributor.
Pull a spark plug, hook it up to a spark tester and ground it, now crank the engine if you get spark coil is ok and in all likelihood so is module.
If you don't get spark test for spark at the coil wire.
If you get spark here and don't get it at the spark plug wire problem is at distributor cap , rotor or spark plug wire. If plugs look bad use a fresh plug to do testing and naturally replace them.
If all of the above are a-ok.
Next is fuel checks. Reinstall fuel pump relay
Easiest fuel check is to put key into ignition cylinder and turn to on position. Lister for pump to buzz or hum. if it doesn't then check fuel pump relay for B+ going to it and leaving it and going to the pump. If B+ making it to pump and it doesn't turn on the pump is your problem. If B+ not making it to pump either the relay or the ignition switch is defective.
Naturally if the pump is defective have a repair shop do the repair . Its dangerous and a real pain.
Now the cutting out after running fora whilrcoild have caused by the coil, ignition module, fuel pump.
We kinda have to get the car to start first to be conclusiveas to why it cuts out.
May 20, 2010 |
1994 Buick Park Avenue