2G 99 GST runs better with cam sensor unplugged?

[Dylan94]

So my car has been having issues. Threw a code for a cam sensor and would only run 3-5 seconds. Got mad and unplugged it and the damn thing started up and runs better than before. Has anyone had this happen or heard of anything like this?

 

[motomattx]

What version of car is it? year? fwd? awd? turbo? non turbo? we would need more information before giving any advice on diagnosing it.

 

[Dylan94]

What version of car is it? year? fwd? awd? turbo? non turbo? we would need more information before giving any advice on diagnosing it.

It was really more of a general question. I didn’t think the car would run at all with it unplugged. But it’s a 99 gst fwd stock other than 1G head swap. Runs fine sometimes. Then will run 3-5 seconds and die. Through a code for cam sensor. Along with EGR stuff I took out. Unplugged sensor and it started running again. Just confused.

 

[luv2rallye]

Are you sure with a 1g head you don't have a 1g CAS with 4 wires (providing TDC and Crank Angle signals) instead of the 2g head's 2g CAS with 3 wires (providing CAS signal)?

 

[Dylan94]

Are you sure with a 1g head you don't have a 1g CAS with 4 wires (providing TDC and Crank Angle signals) instead of the 2g head's 2g CAS with 3 wires (providing CAS signal)?

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It’s the black round one that has one bolt not the flat one. (Still new to the swap so not sure which is which) either way. It shouldn’t run unplugged should it?

 

[luv2rallye]

Did you do the 1g head swap, or did the car come that way, or ???
What ECU do you have, a 1g or a 2g and what year was it for?
BTW - You do know you're missing 2 bolts on the valve cover. But more important the exhaust mani to turbo - 2 are completely missing and the other 2 are not the special factory hardened high strength locking flange type bolts that are needed (you've got 2 ordinary low strength hardware store bolts). Hopefully you just temporarily removed them?

 

[motomattx]

So is the cam sensor that your CURRENTLY running, the one that is in the picture? from what you are describing it sounds like you are running a 1g black top cam sensor.

Its sounding like your timing belt could be off by a tooth or two, you might want to double check that while your in there.

 

[Justin DuBois]

The 2Gb CAM position sensor is common to DSM and EVO - and should run you around $80. Don't get the cheaper $17-20 china sensor of the same format, it won't work.

The cam position sensor tells the ECU which injector to fire, not when to fire. You can run with a completely wrong injector firing - the fuel will hit the back of the intake valve, but the fuel rich air will eventually get sucked in.

 

[luv2rallye]

The cam angle sensor (CAS - aka cam position sensor) also tells the ECU which cylinder pair spark plugs to fire (1,4 or 2,3) [but not when to fire which the crank position sensor (CPS) does]. If the CAS isn't working, the same cylinder pair spark plugs will fire all the time (whenever the CPS says to fire - eg. 1,4 then 1,4 then 1,4 then 1,4 etc - instead of the correct 1,4 then 2,3 then 1,4 then 2,3 etc).

Note: To avoid confusion here on Tuners many posts call the cam position sensor (the Mitsu term), the cam angle sensor (CAS). The crank position sensor is still called that (CPS). Otherwise when someone says CPS you don't know which one they are referring to.

The DSMTuners default definition explanation: https://www.dsmtuners.com/threads/oh-god-code-0340.272874/#post-151302110