Question about crank sensors
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Question about crank sensors
Hi all.
This board seems pretty informative and my question really is a pretty general 3800 issue so I hope nobody minds me asking here..
Other than the obvious interference issue between the crank sensor and the interupter rings on the balancer, how critical is proper alignment of the sensor? I simply don't have access to the alignment tool and towing the vehicle to a dealership is an expensive prospect. I have replaced the crank sensor and the balancer (damaged balancer took out the crank sensor) and have aligned it enough to know there is no interference.
The engine is a '93 3800 N/A transplanted into a P-body. The engine will fire briefly (about half a second) and then die. I know, sounds *almost* like VATS if it actually ran longer - from what I understand, VATS will let it run for 2-3 seconds? My starter circuit is independant from the engine management wiring. No error codes are thrown and the Security light from the ECM is not hooked up, although I can (and probably should) hook a light bulb up to it.
Fuel pressure is 42 PSI with key on and not running and drops to maybe 38-39 when it fires. I have a spare ECM (one was sent out to have the VATS deleted) and spare ignition module that I have interchanged. I am seeing signals through an oscilliscope for both the 3x and the 18x signals from the crank sensor by backprobing the ignition module connector. I *think* I'm getting sequential firing of the injectors during cranking but I haven't verified this yet.
I'm really stumped, the engine ran before the transplant. I could sure use some suggestions!
Thanks
This board seems pretty informative and my question really is a pretty general 3800 issue so I hope nobody minds me asking here..
Other than the obvious interference issue between the crank sensor and the interupter rings on the balancer, how critical is proper alignment of the sensor? I simply don't have access to the alignment tool and towing the vehicle to a dealership is an expensive prospect. I have replaced the crank sensor and the balancer (damaged balancer took out the crank sensor) and have aligned it enough to know there is no interference.
The engine is a '93 3800 N/A transplanted into a P-body. The engine will fire briefly (about half a second) and then die. I know, sounds *almost* like VATS if it actually ran longer - from what I understand, VATS will let it run for 2-3 seconds? My starter circuit is independant from the engine management wiring. No error codes are thrown and the Security light from the ECM is not hooked up, although I can (and probably should) hook a light bulb up to it.
Fuel pressure is 42 PSI with key on and not running and drops to maybe 38-39 when it fires. I have a spare ECM (one was sent out to have the VATS deleted) and spare ignition module that I have interchanged. I am seeing signals through an oscilliscope for both the 3x and the 18x signals from the crank sensor by backprobing the ignition module connector. I *think* I'm getting sequential firing of the injectors during cranking but I haven't verified this yet.
I'm really stumped, the engine ran before the transplant. I could sure use some suggestions!
Thanks
#2
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Thanks, jr's3800.. That'* kind of what I was thinking, but I didn't want to dismiss the crank sensor alignment and kill a bunch of time chasing something else. I've been completely through the wiring 3 times now and it'* been right from the start.
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