Buick Repair Questions? Ask a Mechanic for Answers ASAP
Hello,I will be glad to try and assist you with this,Welcome to Just Answer.
ok from what it sounds like here we know we have spark to the spark plugs or it wouldnt run at all,so we can assume the crankshaft position sensor is ok.
Three things I can think of here that could be at fault is either the camshaft position sensor,the sensors magnet in the cam gear,or the fuel pump module assembly wiring conector.
First the fuel pump module(the metal bracket that the fuel pump sits in in the tank,has wiring that runs from the module down to the pump,on top of this module will be a wiring connectot that runs from the fuel pump up to the module,pull this connector off and make sure the wiring terminals arent burnt,this is common once an old pump starts to draw to many amps it can heat up and burn the wiring terminals on the module in the fuel tank,if this is the case the wiring terminals will have to be replaced.To check this the module assembly with pump will have to be removed from the tank and the wiring connectors on this module and pump will have to be checked.
The cam sensor senses a magnet that seats in the cam gear,this tells the computer when to fire the fuel injectors to give the engine fuel,this cam sensor is located I believe just above the water pump,it has one wiring connector connected to it,remove this sensor(held in with one bolt) and use a mirror and flashlight to look inside the hole at the cam gear,then rotate the engine over by hand and you will see a spot on the cam gear that houses a magnet,look to see if this magnet is still in the cam gear,it may have come apart and fell out(this is very common on these 3.3 engines) if the magnet has fallen out then the timing cover will have to be removed,the cam gear removed and the magnet replaced.In most cases it ends up being this cam gear magnet,it sits in a plastic housing seated in the cam gear and throughout time and heat the plastic housing gets brittle and the cam magnet falls out,when this happens the cam sensor cannot recieve the signal to pulse the injectors to spray fuel in the engine.
If the magnet is in place(not just the plastic housing for the magnet but the magnet itself) then you could have a faulty cam sensor(this isnt as common as the magnet as I have had to only replace a few of these sensors before).One of these issues listed here could be the reasong why you arent getting any fuel.
If when you turn your jey on all the way forward just before you start the engine you hear a hum or buzz noise coming from the fuel tank for two seconds then you know the fuel pump is running and you can skip checking the wiring at the fuel pump module,if you dont hear this noise then it needs to be checked.Also a scan tool might show a fault code for the cam sensor if it does then you know you may have a magnet issue.We have replaced lots of these magnets before for this concern.
I hope this information helped,If you need anything else let me know,If you feel satisfied that I have assisted please click accept as this is how I get paid,positive feedback is appreciated,Thanks Pete.