97 vortec 350 problems - Pirate4x4.Com : 4x4 and Off-Road Forum

440ex · 07-14-2005, 10:12 AM

got some problems here with a vortec 350 .....the first problem was a interminent stalling problem ....so the plugs,wires ,cap and rotor were replaced ...still stalled at ramdom but fires right back up...

so i ran the code scanner on it and it shows no codes , service engine soon light isnt on either ...the ing module was replaced along with a camshaft position sensor and now the thing wont start at all ...it has good spark and its getting fuel , fuel pressure is ok also ...if i remove a plug its soaked in gas but not carbon fouled ...tried to clean the plugs but the same thing happened ..gas soaked ..it almost seems like the timing is screwed up but the distributor wasnt removed or anything ....any help would be awesome right now i am about ready to break shit

mountain4x4 · 07-14-2005, 09:39 PM

Put the old cam sensor and ig. module back in so it'll run. Then check fuel pressure as you drive it, especially as it stalls. If ALL the cylinders are getting too much fuel, the FPR could be bad, if its just 1 or 2 cylinders, those cylinder's fuel injector poppet valves might be stuck open. Dont blindly start replacing crap, that'll start costing you a lot of money for no good reason. Also, dont flood the motor repeatedly or it could cause problems.

Good Luck

440ex · 07-15-2005, 06:40 AM

after it didnt start the first time i swaped the old cam sensor in and it fired ...after it was shut off it wouldnt restart again so i swaped out the IG module with the old ...now it doesnt start at all with the new or old stuff in it ....swaped in new plugs since the were soaked yesterday and re tested the fuel pressure and got 60 psi at the schrader valve .....i can return the cam sensor and Ig module so thats not too big a deal .someone told me these could be the problem thats why i swaped them out ...thanks for the response

mountain4x4 · 07-15-2005, 10:31 AM

I think 60 psi is pretty close, its been a long time since I had my vortec 350 around. Do you continue to flood if the ig switch is "on" and your not cranking the motor? Are all cylinders flooding? Do you have spark at all cylinders?

Its time to start following the flowcharts on the FSM (Factory Svc Manual) for crank no start condition. You'll need the FSM, or maybe someone here will post up the flowchart info...

440ex · 07-15-2005, 11:00 AM

no it doesnt flood if your not cranking the motor ,all cylinders are flooding and sparking equally .fuel pump and relay seem to work fine they pressure up then shut down till crank ..if someone could post that info it would be great since i dont have the manual ......thanks

440ex · 07-16-2005, 10:58 AM

bump.still need some help /ideas on this one

ezzzzzzz · 07-16-2005, 11:35 AM

I suspect a failing crankshaft sensor or faulty wiring connection (grounds ARE critical). I had a similar problem on a 4.3 Vortec. Replacing the CS sensor helped for a while. The whole harness was replaced after I pulled it and rang it out pin to pin but could find no problem. This was after checking every necessary component and cleaning all harness connection points. It ran flawless for two years until the ign module bit the big one one night.

07-14-2005, 10:12 AM	#1 (permalink)
440ex Registered User Join Date: Jul 2003 Member # 21452 Location: PA Posts: 67	97 vortec 350 problems got some problems here with a vortec 350 .....the first problem was a interminent stalling problem ....so the plugs,wires ,cap and rotor were replaced ...still stalled at ramdom but fires right back up... so i ran the code scanner on it and it shows no codes , service engine soon light isnt on either ...the ing module was replaced along with a camshaft position sensor and now the thing wont start at all ...it has good spark and its getting fuel , fuel pressure is ok also ...if i remove a plug its soaked in gas but not carbon fouled ...tried to clean the plugs but the same thing happened ..gas soaked ..it almost seems like the timing is screwed up but the distributor wasnt removed or anything ....any help would be awesome right now i am about ready to break shit

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07-14-2005, 09:39 PM	#2 (permalink)
mountain4x4 Registered User Join Date: Dec 2004 Member # 39602 Location: Colorado Posts: 303	Put the old cam sensor and ig. module back in so it'll run. Then check fuel pressure as you drive it, especially as it stalls. If ALL the cylinders are getting too much fuel, the FPR could be bad, if its just 1 or 2 cylinders, those cylinder's fuel injector poppet valves might be stuck open. Dont blindly start replacing crap, that'll start costing you a lot of money for no good reason. Also, dont flood the motor repeatedly or it could cause problems. Good Luck

07-15-2005, 06:40 AM	#3 (permalink)
440ex Registered User Join Date: Jul 2003 Member # 21452 Location: PA Posts: 67	after it didnt start the first time i swaped the old cam sensor in and it fired ...after it was shut off it wouldnt restart again so i swaped out the IG module with the old ...now it doesnt start at all with the new or old stuff in it ....swaped in new plugs since the were soaked yesterday and re tested the fuel pressure and got 60 psi at the schrader valve .....i can return the cam sensor and Ig module so thats not too big a deal .someone told me these could be the problem thats why i swaped them out ...thanks for the response

07-15-2005, 10:31 AM	#4 (permalink)
mountain4x4 Registered User Join Date: Dec 2004 Member # 39602 Location: Colorado Posts: 303	I think 60 psi is pretty close, its been a long time since I had my vortec 350 around. Do you continue to flood if the ig switch is "on" and your not cranking the motor? Are all cylinders flooding? Do you have spark at all cylinders? Its time to start following the flowcharts on the FSM (Factory Svc Manual) for crank no start condition. You'll need the FSM, or maybe someone here will post up the flowchart info...

07-15-2005, 11:00 AM	#5 (permalink)
440ex Registered User Join Date: Jul 2003 Member # 21452 Location: PA Posts: 67	no it doesnt flood if your not cranking the motor ,all cylinders are flooding and sparking equally .fuel pump and relay seem to work fine they pressure up then shut down till crank ..if someone could post that info it would be great since i dont have the manual ......thanks

07-16-2005, 10:58 AM	#6 (permalink)
440ex Registered User Join Date: Jul 2003 Member # 21452 Location: PA Posts: 67	bump.still need some help /ideas on this one

07-16-2005, 11:35 AM	#7 (permalink)
ezzzzzzz Registered User Join Date: Dec 2002 Member # 15546 Posts: 100	I suspect a failing crankshaft sensor or faulty wiring connection (grounds ARE critical). I had a similar problem on a 4.3 Vortec. Replacing the CS sensor helped for a while. The whole harness was replaced after I pulled it and rang it out pin to pin but could find no problem. This was after checking every necessary component and cleaning all harness connection points. It ran flawless for two years until the ign module bit the big one one night.