i picked up an 04 sunfire a week ago to give me a project to work on but so far it has me stumped, the last owner says it died while she way driving it and they tried replacing a few things with no luck. it cranks fine but will not start, they tried replacing ignition module and crankshaft sensor with no luck. the car has no spark and gets no fuel,and the obd 11 code reading says error linking to system when i try to hook it up. i have traced some ground wires and cleaned them have also checked wires going to the pcm and bcm and cannot see anything wrong.i know my testing needs to go a little deeper but was wondering if anyone might be able to help me at all. and one other thing it does is when you turn the key on all dash lights come on then go out and then the temp warning light, gas light,service light and i believe it is the security light all come back on and the fuel gauge doesn't appear to work either. and sometimes the odometer says error in it. .so i am thinking it is wiring or computer problem. i have checked all fuses they are all good tried leaving the key in for 10 minutes also no luck.
any ideas?
Well lets examine a few things, one by one
You have no spark and no fuel,so we can pretty much eliminate all parts associated with each system.
You have the readind "error" when trying to communicate using a scanner.
So basically the scanner asked the PCM to communicate, it got no response, so it tried again, after two failed contact attemtps it will send back an "error"
Sounds either your PCM is dead, your PCM fuse is blown, or your PCM ground is faulty.
A dead PCM you will be able to crank the car, but a dead PCM will cause no spark/fuel
Do you have a noid light by chance, to checkfor injector pulse,
- 2004 Cavalier - 124k, owned since new
no i don't have a noid light, now i did find something new out tonight i pulled the valve cover off and the chain guide at the top that has the plastic piece on it is broken and i only see half of it, the chain is still intact and seems like it might be a little loose. i know that can't cause all of theese problems but can it cause the pump to not even try to prime when first turning the key?
i found it. make sure u have a fully charged battery and then wiggle the connectors of the body control module while you crank the engine. it should start. i found the wires are routed underneath the carpet where the drivers left foot would be. if the driver pushes on the floor with his left foot he is actually tugging on the bcm connectors. i simply rerouted the wires behind the hood latch release and it cranks everytime.
