car turns on and shuts off

[davis.ryan23]

My 99 galant has a problem. When you start it up the car shakes and shuts off. However if u apply gas the car won't cut off but if u let off the gas the car cuts off. Anyone know what the issue is.

[fliegendaffe]

bad sensor throttle sensor?

[davis.ryan23]

are you talking about the throttle position sensor . if so how would you go about testing that?

[Reelax]

u might just need a new battery. have the battery and charging system checked. also clean the throttle body and MAF if you haven't recently.

[skyhigh90210]

check for vacuum leaks

[jlfisher360]

i had the same problem. if you can unplug the mass air flow sensor and it will run(rough, not normal), then you have a cracked intake manifold. If that doesnt work, you probably have a faulty Idle Air Control Valve. Trust me, i took my car to 4 different shops and i got different answers at every one. Just save your time and money and pay the $100 and take it to the dealership to let them check it out. And if its the cracked manifold, they're gonna want to charge you $1000 to fix it, just say no and drive home and try to buy a manifold online and either replace it yourself or take it to a small time mechanic. And you should be able to drive it by shifting from L-2nd-3rd-drive and put it in neutral and coast(while keeping the engine revved to about 1000 rpm) to stoplights and stop signs.

[jlfisher360]

And before you take it anywhere, do what Reelax said and buy some throttle body cleaner and clean around the inside of the metal flap. That, combined with unplugging the MAF harness from the intake, should allow you to drive it some.