Gatorade1987
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- Apr 5, 2012
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Hi guys,
I've been all through the forum and haven't found anyone with a simalier problem. I'm Olds noob but long time GM guy. Thanks in adavance for any help!
Basically whats going on is, the car came into our shop as a no start. After doing diagnostics, we discovered it had no injector pulse. The car does have spark. I can make it fire if I put fuel directly into the intake. What we've tried so far is an igntion module, a crank sensor and cam sensor. When I replaced the cam sensor I noticed the interupter magnet in the cam gear was powdered, so I replaced that as well being sure I'd located the issue. However, still no start. The fuel injectors are powering up and if I ground them manually, the car will fire on that cylinder. At this point I then checked all of the wiring from the cam sensor, crank sensor, ignition module, and injector harness. All had continuity. I checked the injectors for proper resistance and all ohm'ed out ok. I then tried a new ECM thinking that was the issue. Still no pulse. The ECM is grounding, just not grounding the injectors. One thing I am not sure on is if the OBD-I ECM needs to be flashed or not. . . I thought changing the PROM was the only step to making it able to work with the car. I tried using the flow charts from GM but that didn't prove helpful as they contined to point to the crank sensor, even after changing it a few times (I assumed it is possible to get a bad one). Also, supposedly, by manually triggering the purple/white wire on the ignition module, the injectors should pulse, thereby proving a bad ignition module. No avail. But that wire isn't broken anywhere from the ECM to the module. Also, I haven't been able to get my OBD scanner to communicate with the car. . .that may or may not be pertanant information. (it's a Matco Scanner).
To reiterate, the car has spark but no injector pulse.
Any thoughts?
Thanks
Gator
I've been all through the forum and haven't found anyone with a simalier problem. I'm Olds noob but long time GM guy. Thanks in adavance for any help!
Basically whats going on is, the car came into our shop as a no start. After doing diagnostics, we discovered it had no injector pulse. The car does have spark. I can make it fire if I put fuel directly into the intake. What we've tried so far is an igntion module, a crank sensor and cam sensor. When I replaced the cam sensor I noticed the interupter magnet in the cam gear was powdered, so I replaced that as well being sure I'd located the issue. However, still no start. The fuel injectors are powering up and if I ground them manually, the car will fire on that cylinder. At this point I then checked all of the wiring from the cam sensor, crank sensor, ignition module, and injector harness. All had continuity. I checked the injectors for proper resistance and all ohm'ed out ok. I then tried a new ECM thinking that was the issue. Still no pulse. The ECM is grounding, just not grounding the injectors. One thing I am not sure on is if the OBD-I ECM needs to be flashed or not. . . I thought changing the PROM was the only step to making it able to work with the car. I tried using the flow charts from GM but that didn't prove helpful as they contined to point to the crank sensor, even after changing it a few times (I assumed it is possible to get a bad one). Also, supposedly, by manually triggering the purple/white wire on the ignition module, the injectors should pulse, thereby proving a bad ignition module. No avail. But that wire isn't broken anywhere from the ECM to the module. Also, I haven't been able to get my OBD scanner to communicate with the car. . .that may or may not be pertanant information. (it's a Matco Scanner).
To reiterate, the car has spark but no injector pulse.
Any thoughts?
Thanks
Gator