need pcm help
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need pcm help i have a 94 lt1 trans am the issue im having is im not getting an injector pulse on cylinders 2,4,6,and 8 but im getting a pulse on 1,3,5,7 which ive already checked all wiring and grounds for the engine and pcm can someone maybe shed some light on what other sensors have to communicate with the pcm in order for the injectors to get voltage any diagnostic flow charts and schematics would be greatly appreciated i just havent been able to enuff information to determine a cause yet
Last edited by 2000badbird; Sep 8, 2009 at 10:36 AM.
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yeah um im a lil past that stage ive checked the wires fuses measured resistance of the wires checking for continuity checked all grounds anyone else have any ideas
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With the way the injectors are fused and signal wires come from the PCM, it is almost impossible to have one bank dead and not the other. There is no sensor that would cause some not to fire and others work. You need to verify power to all injectors and use a noid light to check for PCM pulses. It would be very odd for the PCM to not be sending pulses to one bank, but I guess it could happen.
http://shbox.com/1/smfi_devices_injectors.jpg
On a 1994 power goes through C100 A and K to the fuses.
http://shbox.com/1/harness_connector_faces.htm
http://shbox.com/1/smfi_devices_injectors.jpg
On a 1994 power goes through C100 A and K to the fuses.
http://shbox.com/1/harness_connector_faces.htm
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i have used a noid light thats how i determined that 2,4,6,8 dont have a pulse whereas 1,3,5,7 do this is a very very odd problem ive never encountered any thing like this before
I know you said you checked them, but check again the C-100 Connector first like mentioned, see if both of them are hot. If they aren't then there is your problem.
If they are, then check the Pink on the 2, 4, 6, 8 Injectors and see if they are hot. If not then there is a break in the Harness somewhere.
If they are hot then you have a pretty wierd problem..
If they are, then check the Pink on the 2, 4, 6, 8 Injectors and see if they are hot. If not then there is a break in the Harness somewhere.
If they are hot then you have a pretty wierd problem..
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well i found the problem a small rodent decided to chew into the wiring harness under the underhood fuse box so i repaired the damage and the car runs again thank you all for your help
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