I've no spark to my sparkplugs. Engine turns over but wont fire. Already changed coil, coil module and crankshaft sensor. Any idea's? Been told that it could be ecu but these are very expensive for a car that's 17 years old. Car is a 3.2 litre straight 6 XJ. Any help appreciated. Thanks.

Crankshaft position sensor,cam sensor . your vehicle should have coil on plug , a coil at each spark plug !
Ignition Coils
Each ignition coil has an ignition 1 feed and a ground. The PCM supplies an ignition control (IC) circuit. Each ignition coil contains a solid state driver module as its primary element. The powertrain control module (PCM) signals the coil driver to initiate a firing event by applying a signal to the IC circuit at the appropriate time. When the signal is removed, the coil fires the spark plug. The spark plugs are tipped with platinum for long wear and higher efficiency.
During normal operation the powertrain control module (PCM) controls all ignition functions. If either the crankshaft position (CKP) or camshaft position (CMP) sensor signal is lost, the engine will continue to run because the PCM will default to a limp home mode using the remaining sensor input. As mentioned above, each coil is internally protected against damage from excessive voltage. If one or more coils were to fail in this manner, a misfiring condition would result. Diagnostic trouble codes are available to accurately diagnose the ignition system with a scan tool.
If a crank sensor is replaced a Crankshaft Position System Variation Learn must be done and a scan tool is need to do this.

so changed spark plugs after or before run over puddle?

standing passenger side vechicle with crankshaft pulley facing your.number one sparkplug location should be at twelve Oclock position.you need to know cylinders locations front cylinders left to right is 1 3 5 7 and back cylinders left to right is 2 4 6 8 and firing order is 1 8 4 3 6 5 7 2 your ignition timing need to be 10 degrees BTDC AT 800 RPM. YOU SET TIMING YOU NEED TO DISABLE SPARK ADVANCE BY CONNECTING JUMP WIRE OR PAPER CLIP STRECTCH AND BEND YOU NEED TO CONNECT JUMPER WIRE TO A AND B DLC TERMINALS. if ignition timing way off you wont get no spark.but check ignition fuse and make sure distributor cap and rotor good shape also spark plugs and wires.if all is good your ignition module or ignition coil bad.the 4.9 can be time if you have 4.6 engine cant adjust ignition timing PCM control timing.code scan vechicle first before buying new parts.look for ignition module or pcm fault codes.look for faulty crankshaft sensor or camshaft sensor.many things will cause no spark conditions.

Learning how to test a GM distributor less ignition system rather then guessing an replacing parts is the proper way to diagnose . Pulling a couple of pull wires of the same coil an having someone crank the engine over to see if there is spark would the first test . If there is no spark ,could be the ignition module , or the crankshaft postion sensor .
GM 3 8L Ignition Control Module And Crank 3X 18X Sensor Test

if it not firing change the coils if thats not it then you may want to check the fuse but if not firing i would check the coil because where they are located on the engine under the mainfold it gets real hot there

Insert each wire on the proper terminal of the ignition coil. Ensure that the coil boots are fully seated and both locking tabs are engaged. The terminals are identified on the ignition coils. Install wires as shown in the illustration. The 2.3L firing order is 1-3-4-2 for both ignition coil assemblies.

Distributorless Ignition System In the distributorless ignition system (DIS), all engine timing and spark distribution is handled electronically with no moving parts. This system has fewer parts that require replacement and provides a more accurately timed spark. During basic operation, the EEC-IV determines the ignition timing required by the engine and a DIS module determines which ignition coil to fire.

Components
The distributorless ignition system (DIS) for the 2.3L twin spark plug engine consists of the following components:

• Crankshaft timing sensor
• DIS module
• Two ignition coil packs
• Spark angle portion of EEC-IV

Crankshaft Timing Sensor
The crankshaft timing sensor is a dual hall effect magnetic switch, which is actuated by the dual vane cup on the crankshaft pulley hub assembly. This sensor generates two separate signals, PIP (profile ignition pick-up) and CID (cylinder identification). The PIP signal provides base timing and RPM information, while the CID signal is used to synchronize the ignition coils. Initial timing (base timing) is set at 10 degrees BTDC and is not adjustable. Ignition Coil Packs
Two ignition coil packs are used for the 2.3L dual plug engine. The two ignition coil packs are triggered by the DIS module and are timed by the EEC-IV. Each coil pack contains two separate ignition coils for a total of four ignition coils. Each ignition coil fires two spark plugs simultaneously, one spark plug on the compression stroke and one on the exhaust stroke. The spark plug fired on the exhaust stroke uses very little of the ignition coils, stored energy, and the majority of the ignition coils, energy is used by the spark plug on the compression stroke. Since these two spark plugs are connected in series, the firing voltage of one spark plug will be negative with respect to ground, while the other will be positive with respect to ground. Refer to thePowertrain Control/Emissions Diagnosis Manual for additional information on spark plug polarity. DIS Module
The main function of the DIS module is to switch between ignition coils and trigger the coils to spark. The DIS ignition module receives the PIP and CID signals from the crankshaft timing sensor, and the SPOUT (spark out) signal from the EEC-IV module. During normal operation, PIP is passed on to the EEC-IV module and provides base timing and RPM information. The CID signal provides the DIS ignition module with the information required to switch between the coils for cylinders 1 and 4 and the coils for cylinders 2 and 3. The SPOUT signal (from the EEC-IV) contains the optimum spark timing and dwell time information. The dwell time is controlled or varied by varying the duty cycle (duration) of the SPOUT signal. This feature is called CCD (computer controlled dwell). Therefore, with the proper inputs of PIP, CID and SPOUT the DIS ignition module turns the ignition coils on and off in the proper sequence for spark control. CID is also sent to the EEC-IV micro-processor to allow for Bank to Bank fuel control. Failure Mode Effects Management
During some DIS system faults, the Failure Mode Effects Management (FMEM) portion of the DIS ignition module will maintain vehicle operation. If the DIS ignition module does not receive the SPOUT input, it will automatically turn the ignition coils on and off using the PIP signal. However, this will result in fixed spark timing (ten degrees BTDC) and a fixed dwell time (no CCD). If the DIS ignition module does not receive the CID input during engine cranking, random coil synchronization will be attempted by the module. Therefore, several start attempts (cycling the ignition from OFF to START) may be required to start the engine. If the DIS module loses CID input while engine is running, the module will remember the proper firing sequence and continue to fire to maintain engine operation. Dual Plug Inhibit
Dual Plug Inhibit (DPI) is a function of the EEC-IV that is only used when the vehicle is being started at temperatures -7° C (20° F) and below. During engine cranking, the EEC-IV will only fire the spark plugs on the right hand side of the engine. When the engine has started, the EEC-IV will send a signal to the DIS module to start normal dual plug operation. Ignition Diagnostic Monitor
The Ignition Diagnostic Monitor (IDM) is a function of the DIS module. The DIS module sends information on system failures to the EEC-IV which stores the information for diagnostic self test. The IDM signal also is used to drive the vehicle instrument tachometer, and test tachometer for system

CRANKSHAFT POSITION SENSOR

Fig. 8 Ignition Coil Module Assy 2.5L/4-151 The Crankshaft Position Sensor is mounted remotely on the bottom side of the ignition module.

RH Side Of Engine.

Front RH Side Of Engine

Applicable to: Cutlass Ciera & Cutlass Cruiser w/V6-231/3.3L

what engine? 3.0L 2 Valve? 4 Valve?
3.4L SHO engine?

The PCM (engine computer) fires the coils, but it is never the cause of a problem. I suspect it is the crankshaft position sensor on the front of the engine by the crank pulley. easy to change.

Crankshaft Position Sensor The crankshaft position sensor (CKP sensor) (6C315) is a variable reluctance sensor triggered by a 36-minus-1 tooth trigger wheel located on the crankshaft pulley and damper. The signal generated from the crankshaft position sensor is called the crankshaft position (CKP) signal, which provides base timing and crankshaft speed (rpm) information to the ignition control module (ICM) (12K072). Base timing is set at 10±2 degrees before top dead center (BTDC) AND IS NOT ADJUSTABLE. The powertrain control module (PCM) (12A650) will use this information with the spark advance information to determine ignition coil (12029) turn on or turn off time.

check your fuse box then your coil pack

depends on the engine. most of these cars are computer controlled and use crankshaft and camshaft sensors to properly send timing and fire info to allow the car to start and run. Coils in these engine are usually a pack bolted on the left side of engine (sparkplugs will feed from them to the sparkplugs.

Crankshaft and Camshaft sensor for GM are usually mounted at the harmonic ballancer, the sensor have three to four wires in them check for old rubbery wire and broken insulation first, if alot of oil or antifreeze is on the wire it will break down the plastic covering. If wire is bad replace the wire. If wire is good then change the sensors and all should be good.