1. Ignition System Components (Beyond the Coil):
* Ignition Switch: This is a common failure point. A faulty switch may not be providing consistent power to the rest of the ignition system. Test for power at the switch's output when the key is in the "start" position.
* Ignition Control Module (ICM): This module controls the firing of the coil. A failing ICM can produce intermittent spark. These are often prone to heat issues; check for heat damage.
* Crankshaft Position Sensor (CKP): The engine computer needs the CKP to know where the engine is in its rotation cycle to fire the coil at the right time. A failing CKP will result in no spark. It's usually a relatively cheap part to replace.
* Cam Position Sensor (CMP): (Some engines had this, some didn't - check your specific engine details) Similar to the CKP, this sensor plays a crucial role in ignition timing.
* Wiring: Look carefully for damaged, corroded, or loose wiring harness connections between the ignition switch, ICM, coil, sensors, and distributor (if equipped). Pay close attention to any areas that might get hot (near the engine or exhaust). A vibration could cause a poor connection to come and go.
2. Power and Ground:
* Battery Voltage: Ensure your battery is fully charged and the connections are clean and tight. A weak battery can cause erratic behavior.
* Ground Connections: Poor ground connections can prevent the ignition system from working correctly. Check the main engine ground strap and any ground connections to the ignition components.
3. Distributor (If Equipped):
* Distributor Cap and Rotor: If your van has a distributor, inspect the cap and rotor for cracks, arcing, or wear. Replace them if necessary. A worn distributor cap can lead to intermittent misfires or no spark.
* Pick-up Coil (Inside Distributor): This coil senses the crankshaft rotation in older distributor-equipped engines. If damaged it will prevent the ICM from sending signal to fire the coil.
4. Diagnostic Steps:
* Check for Power at the Coil: With the key in the "start" position, use a test light or multimeter to check for power at the coil's positive terminal. There should be power there only when cranking.
* Check for Spark at the Coil: A spark tester (available at auto parts stores) is crucial. Disconnect the wire going to the distributor (or coil directly if no distributor) and hold the spark tester's ground clip to the engine block. Have someone crank the engine while you watch the spark tester. A strong spark indicates the coil and ignition system are working, while no spark points to a problem before the coil.
* Use a multimeter: This allows more precise voltage and resistance testing on all the components mentioned.
* Check for trouble codes (if equipped): Your van may have a check engine light and diagnostic port. A code reader can pinpoint specific problems.
Important Notes:
* Safety First: Always disconnect the negative battery terminal before working on any electrical components.
* Systematic Approach: Don't just randomly replace parts. Follow a logical troubleshooting process by checking power and ground before moving to more complex components.
* Professional Help: If you're not comfortable working on your vehicle's electrical system, it's best to take it to a qualified mechanic.
The fact that it ran for 10 minutes suggests a heat-related problem in a component like the ICM or a wiring connection that expands and contracts with temperature. Focus your investigation on those possibilities first. Good luck!
