Chevy 2500 wont start

MichaelVSr · 06-24-2009, 05:05 PM

89 Chevy 2500
4x4/Auto

I am getting fuel pressure up to the TBI but not into it. There's no spark out of the coil but it is getting power. I checked all the fuse able links and they are hot. I also checked the fuses and the are good. The engine cranks fine. There are no diagnostic codes stored.

I just changed the fuel filter, cap, rotor, and plugs recently. It ran great for 10 miles and then wouldn't start again until I wiggled the distributor wires and it ran fine for another couple miles. Now it wont start again.

**octaneman** · 06-25-2009, 12:18 PM

Hi MichaelVSr

When you wiggled the harness that indicates a bad connection or loose wire somewhere , or a bad connection to the ignition module. Look for any broken or corroded wires within the distributor harness, clean and re-tighten all grounds that lead to and from the distributor. Check all connections to the coil see that they are not loose.. If it still doesn't start, there is a good possibility that the ignition module failed.

MichaelVSr · 06-26-2009, 06:44 PM

i tested the ignition module and it was good. i replaced the coil and there no change.

**octaneman** · 06-26-2009, 08:19 PM

Attach a node light to the injector plug and while cranking the engine look to see if there is a signal , the node light will flash very fast if there is one. If the node light does not flash then the no start problem is compounded. If testing the ignition module, wires connections, cam/ crank sensors, and recently replaced coil was OK, then everything is pointing to the ECM. But... Before you condemn the ECM, you will have to perform a series of tests to be absolutely sure that it has failed. First, you must make sure that you are getting crank sensor signal voltage, if the voltage is there check the position of the pickup coil in relation to the crank signal. Test the pickup coil to verify that power is present and by using an ohm meter check it's readings and see if they are according to specs. Since you are getting power to the coil, then the signal is lost from the pickup to the module. Make sure that the module is well grounded, and verify the signal voltages from the module to the ECM, if the ECM does not give a signal return to either the injector or the module then the ECM is faulty.

If you can get your hands on a wiring diagram please post it.

post back your findings.

MichaelVSr · 07-17-2009, 09:46 PM

octaneman i let the truck sit for 2 weeks and it starts and runs fine. also no crank sensor.you helped me on 6 26 09

06-24-2009, 05:05 PM	#1 (permalink)
MichaelVSr Registered User Join Date: Jun 2009 Posts: 3 OS: WinXp	Chevy 2500 wont start 89 Chevy 2500 4x4/Auto I am getting fuel pressure up to the TBI but not into it. There's no spark out of the coil but it is getting power. I checked all the fuse able links and they are hot. I also checked the fuses and the are good. The engine cranks fine. There are no diagnostic codes stored. I just changed the fuel filter, cap, rotor, and plugs recently. It ran great for 10 miles and then wouldn't start again until I wiggled the distributor wires and it ran fine for another couple miles. Now it wont start again.

06-25-2009, 12:18 PM	#2 (permalink)
octaneman Mentor Home Support, Gearhead Automotive Center Join Date: May 2009 Posts: 544 OS: WINXP	Re: Chevy 2500 wont start Hi MichaelVSr When you wiggled the harness that indicates a bad connection or loose wire somewhere , or a bad connection to the ignition module. Look for any broken or corroded wires within the distributor harness, clean and re-tighten all grounds that lead to and from the distributor. Check all connections to the coil see that they are not loose.. If it still doesn't start, there is a good possibility that the ignition module failed.

06-26-2009, 06:44 PM	#3 (permalink)
MichaelVSr Registered User Join Date: Jun 2009 Posts: 3 OS: WinXp	Re: Chevy 2500 wont start i tested the ignition module and it was good. i replaced the coil and there no change.

06-26-2009, 08:19 PM	#4 (permalink)
octaneman Mentor Home Support, Gearhead Automotive Center Join Date: May 2009 Posts: 544 OS: WINXP	Re: Chevy 2500 wont start Attach a node light to the injector plug and while cranking the engine look to see if there is a signal , the node light will flash very fast if there is one. If the node light does not flash then the no start problem is compounded. If testing the ignition module, wires connections, cam/ crank sensors, and recently replaced coil was OK, then everything is pointing to the ECM. But... Before you condemn the ECM, you will have to perform a series of tests to be absolutely sure that it has failed. First, you must make sure that you are getting crank sensor signal voltage, if the voltage is there check the position of the pickup coil in relation to the crank signal. Test the pickup coil to verify that power is present and by using an ohm meter check it's readings and see if they are according to specs. Since you are getting power to the coil, then the signal is lost from the pickup to the module. Make sure that the module is well grounded, and verify the signal voltages from the module to the ECM, if the ECM does not give a signal return to either the injector or the module then the ECM is faulty. If you can get your hands on a wiring diagram please post it. post back your findings.

07-17-2009, 09:46 PM	#5 (permalink)
MichaelVSr Registered User Join Date: Jun 2009 Posts: 3 OS: WinXp	Re: Chevy 2500 wont start octaneman i let the truck sit for 2 weeks and it starts and runs fine. also no crank sensor.you helped me on 6 26 09