My 97 Protege 1.5l has a rough start. It shakes a lot at low rpms and I smell gas. When it idles it seems like the car is going to stop (the rpms go below normal)
I have been told it has a crack on the exhaust manifold. I am also suspicious about one of the fuel injectors. I unplug the injector and there is no response from the car...
Can anyone tell me if one or the other is the most probable cause?
If the problem is the manifold do I need a new catalytic converter if the problem is just a cracked manifold?
Thanks in advance!
Jimian

 

there is no way that it's your exhaust manifold.

that sounds more like an idle/ignition or air/fuel ratio issue, definitely prior to combustion. check your idle control valve (? not sure if this car has one) and your intake manifold.

the gas smell is probably a separate issue. although its possible its an injector, i doubt it. check your fuel lines for leaks with the gas smell, that's where i would start on that.

 

Thanks for the reply. Another problem that the car has is that the beginning of the driving is hesitant. I press the gas but the car does not accelerate smoothly. rather the acceleration is bumpy and unstable. Are these symptoms of the same problem? What would be the symptoms of a cracked manifold? I was told a couple of times that the manifold was cracked.
Thanks!

 

based on that information, it sounds like it could be an ignition coil. or sometihng relation to ignition. not your exhaust manifold. it would be SUPER noisy if you had a crack in the manifold, not to mention that is highly unlikely. (its cast steel)

 

These cars are not very noisy if they have any holes before the muffler. Sometimes you have to go looking for them to find them.

The combination of the cracked exhaust mainfold and the bad fuel injector will cause all the problems you list, including the fuel smell in the cabin. You basically have a mist of fuel being sprayed down the exhaust while you are driving. Also, check your fuel filter. Then, after changing the bad fuel injector and exhaust manifold, replace the plugs.