I dont seem to be getting an electronic pulse at the injectors. The injectors seem to open when they are hot wired but not connected to the wireing harness. Everyhing seems to be hooked up right. I hooked up a noid light to the injector plug and no flash. I also replaced the ingition module which was tested at a local parts store and they said it was bad, althoug I was still getting a spark. hmm. Anyone got some ideas or suggestions? Thanks

DT

Then you need to check the line going from the module to the ECM. The ECM much see those pulses from the ignition module to fire the injectors.

You may want to pull, clean, and reseat the ECM harness connectors. I presume this is for an MPFI V-6, right? No VATS? What year?

Important, does your tach needle move when you crank the engine and are you getting spark at your plugs?

I am getting spark at the plugs. The car will fire as if the cold start injector put a little fuel in but then when thats gone nothing. So it sounds like its starting up, but won't keep runnning. I will check to see if there is a pulse to the ecm. i will also have to check on the tach tommorrow morning. Right now Im feeling too defeated to go out. lol Any other ideas? Can the ignition module be bad even if I am getting spark? I put a new one in yesterday and still no pulse. hmm How does the ignition module work, and is there a diagram of the ecm out there anywhere?

[This message has been edited by DR650SE (edited 01-06-2006).]

Do you get the strandard (alt oil, temp) lights on your dash when you first turn the key? If not your ecm may not e getting power. My '84 was doing this recently, it would spark, but no fuel.

I think it is getting lights, I'll double check in the morning. How would I fix this and what would cause it to not get power to this and get power to other things like the radio or starter/ignition?

Edit: this is an 86 SE with a 2.8L stock v-6 with a manual tranny if that helps.

[This message has been edited by DR650SE (edited 01-06-2006).]

Do you get a "Check Engine" light if you turn on the ignition? If you don't, then the ECM is not getting primary battery power. There is a single wire connecter back by the battery. If it's not plugged in all the way the ECM won't get power and the injection won't work.
If you do get the light, then the problem may be in the wiring between the distributer and the ECM.

------------------
Rod Schneider, Woodstock, Ga.
"You can't have too many toys!"
1988 Fiero GT
1966 Porsche 911
Van's RV-6 airplane-under construction

thanks for the suggestions guys, that power line may very well be the problem, I hope it is. If it is I'll feel like a dumb@$$ but thats life. I'll check in the am. if not, im sure you'll here from me.

Edit: my fuel pump is running, would this run if the ecm was not hooked up?

[This message has been edited by DR650SE (edited 01-06-2006).]

The module has a basic timing map built into it and will fire the plugs even if there's a faulty connection between it and the ECM, however, the ECM must see the EST pulses before it will fire the injectors.

I think I've covered this in previous threads, but here are some simple tests. First, get a trouble light, connect the clip to ground and probe the Fuel Pump Terminal in the ALDL connector:

Now, turn the key on but don't crank. Does the light come on for around two seconds then go off? If so then the ECM is working fine as far as it having power and responding. Next, unplug the oil pressure sender and try cranking the engine. Does the test light come on? If so, that means the ECM is seeing EST pulses from the distributor module. If the test light comes on when first turning the key to RUN before cranking, but does not come on when cranking, that tells me the ECM isn't seeing the distributor module for some reason.

If all of the above tests are successful, connect the test light to power and probe a known ground to verify the light works. Next, probe the two wires at the ECM that feed the fuel injectors, per this schematic:

When probing each wire at the terminal, crank the motor. The ECM works by providing ground for the injector coils, the other side of the injectors are connected straight to full time power via the ignition switch. If the light blinks on and off while cranking it means the ECM side of the injector circuit is working fine. If not, and the ECM otherwise is working and runs the fuel pump when cranking then the ECM has got problems internally.

Once you verify the ECM is working then use the test light connected to power to probe the injector harness connector by the thermostat for pulses. If you get pulses at the ECM but not at the connector (probe the correct wires per the schematic) then the harness has a problem. If it blinks at the harness then you connect the test light to ground and probe the other wires in the harness connector. If you have power there then the problem is in the injector harness under the manifold plenum.

It's really a simple circuit, not to terribly difficult to troubleshoot with just a test light.

JazzMan