Pontiac Repair: 95 pontiac transport, canister purge valve, crank sensor

Question
I have this van that after it starts warming up the idle goes up and down. Most of the time it will stall if you dont have 1ft on brake and 1 on gas. The codes I got were p0341, p1640 & p1670, The 1st 1 is for crank sensor performance witch I just change sensor after I got the codes but still does same thing. The other 2 I'm not sure what they are and what i'm to do to repair these problems. Can you help me out?

Answer
Hi Bob:

the 341 is a cam sensor code. If this engine has a lot of miles on it I would look at possably the magnet on the cam shaft gear broke off. It held into the gear by a plastic retainer and after eniugh heat cycles the retainer breaks off and the magnet drops into the oil pan. That was pretty common back in the day. take the Cam sensor out and use a socket and a ratchet and roll the engine over while using a mirrior to look for the magent to make sure it's still in the cam gear. you may need to turn the crank over 2 time to get to where the magnet is on the cam if it's missing the timing cover has to come off and replace the magent. as for the 1640 and 1670 those are quad driver codes a quad driver is a solid sate "relay" for all intensive purposes in the computer they in turn turn on a relay or a solenoid for in the tranmsssion or the canister purge valve or the a/c compressor. you hve to have other thing that are not working on the van when those codes set. if they are a current code hat ever the driver oprates will be in op. Those codes are usually cuased by a short in the wiring of in the device the driver is controlling. The quad drivers are current sensing if the current is more of less then expected when it's commanding on a component it will set that code. Good luck :)