Hi Everyone,
I had problems about 2 weeks ago with my Stratus SE 2 door coupe (engine size 2.4). The car would buck when at a stoplight, and I would have to put my foot on the gas very slow otherwise the RPM's would go up to about 2-3000 before the gas would kick in and I could get up to speed. Sometimes I would be at a stoplight, and the car would rev up to 2000 rpms down to less than 1000, and it would keep doing this. Sometimes it would go all the way down and stall out. I took it to the shop, and they told me it was wires and fuses. I got those replaced and still had the issue. Then they tell me its the TPS, and they replaced that. It's still doing it, just not as bad. Is there something wrong with perhaps my fuel injectors? I'm hoping there's nothing wrong with the fuel system. This morning it stalled out again, but it seems like after I've driven it a while, it does not happen. I don't know whats wrong, but if this shop wants me to keep pouring money into this car - so far I've spent $500 getting the fuses and TPS fixed - I can't afford much more. I want to make sure I'm not getting stiffed. The engine light is still on. It went on about 5 min after driving it off of the shop.

Thanks to everyone in advance for your help.

-Shell

 

Sounds like you need to find a new technician who knows how to do a complete diagnosis besides throwing parts at a problem. There's more than one sensor or system that can contribute to an idle problem. The PCM ultimately sets the idle speed based on sensor inputs. One bad sensor sends false signals that are mis-interpreted by the PCM which can cause goofy idle problems like you describe. For example:

The idle air control motor (IAC) attaches to the throttle body. It is an electric stepper motor.

The PCM adjusts engine idle speed through the idle air control motor to compensate for engine load, coolant temperature or barometric pressure changes.

The throttle body has an air bypass passage that provides air for the engine during closed throttle idle. The idle air control motor pintle protrudes into the air bypass passage and regulates air flow through it.

The PCM adjusts engine idle speed by moving the IAC motor pintle in and out of the bypass passage. The adjustments are based on inputs the PCM receives. The inputs are from the throttle position sensor, crankshaft position sensor, coolant temperature sensor, MAP sensor, vehicle speed sensor and various switch operations (brake, park/neutral, air conditioning).

It's also possible fuel injector problems could contribute to the idle problem you are experiencing as well. Fuel pumps another possibility. Even the PCM could be the problem.

The first step is to check for trouble codes that are stored in the PCM. Is the check engine light on? If yes, you just need to read the code with a code reader. Places like Autozone or O' Reilly's may do it for free. If not, scan for pending codes. These stored codes are useful in diagnosing problems even if they haven't turned the light on yet. Stored codes, however, may require an expensive type of scan tool to retrieve them.

There are diagnostic flow charts for troubleshooting these codes available on the internet. Lots of help here or other forums as well. All you need to know is the code to search for.

Hope this helps a little and good luck getting your problem resolved.

 

Do you know what the code is, that cause the check engine light to come on?

 

Unfortunately, they did not write up the code on the receipt they handed me. This car is a 2002, it has 160,000 miles on it, maybe its time to just replace it with a new car. I'm wary of mechanics for this reason: I don't know whats wrong with the car so they can tell me, "Oh its this! No - wait, it's this." I think I'm going to print this out and bring it to that mechanic and see what he says.

Thanks,
Shell

 

Have u tried replacing the actuator? this could be the cause, and also your fuel system should be properly diagnosed, i will also recommend you do a scan o the car.