Club president is having trouble with his K car.

[89ARIES]

Hellow fellow members. Can you offer me some advice? I am having a minor problem with my 1989 Dodge Aries LE Coupe. Original 2.5 liter TBI motor with 120,000 miles. Car runs good, except for chronic check engine light problems. Here is the issue:

Well, just for the heck of it, I retrieved my engine codes last night. Argh, all the same check engine light codes I had before the throttle body was rebuilt all resurfaced. Now, I have a code 23 pointing to throttle positioning sensor failure. I want to wait until I get back from Sacramento to fix it, unless it is really a problem. What do they mean by the term "vaporizing" as an issue. I have heard that the TPS? is suppossed to prevent "vaporizing" but that often the logic module will kick in and still read the other sensors to compensate for a failed TPS. I assume my 02 and coolant sensor are okay as I am still getting great gas mileage. I suppose I should replace the TPS? Here is the strange pattern I have noticed with the check engine light that seems to be directly or indirectly related to the throttle body somehow. Mabye the TPS, like one of you guys mentioned, would explain the intermittent surges of power while cruising at 55mph my car has been experiencing for a year. Here is the pattern of codes the logic module has thrown in a consitent order twice now during the last year.

Before throttle was rebuilt in December 2007:

February 2007: Code 31
April 2007: Code 37 next
August 2007: Code 25 next.
During this time, the frequency of surges of power while cruising our increasing.

After throttle was rebuilt, car stopped stalling and ran much better. But,

January 2008: Code 31 returns
March 2008: Code 37 returns
April 2008: Code 25 returns
Recently: Code 23 returns.
Surges of power while cruising our returning. Not as often yet. Once or twice last year, the car actually violently once or twice bucked on the freeway from the surges.

So, as you see, there is a definite pattern to these codes. I hope this helps. The battery was disconnected after throttle was rebuilt, and then the codes started accumulating over time again. Also, since January, the check engine light turns on, stays on, turns off, stays off for a day, comes back on again, does the flickering for a couple minutes, all random.

I am hoping maybe the TPS is to blame and can be easily replaced, or is my car screwed with a major electrical problem. The car is not stalling, YET.

Here are the codes from minimopar: Code 31 EGR: Purge canister/EGR selenoid circuit is open or shorted.
Code 37 NA: Part throttle unlock (PTU) selenoid circuit is open or shorted.
Code 25: AIS (Automatic Idle Speed) motor circuit shorted or target idle speed not reached
Code 23 TBI: Throttle Body temperature sensor out of range. Needs to function to reduce risk of vaporizing. Logic module should go to limp mode and be able to read other sensors to compensate for sensor out of range.

Of course, since K cars never idled perfectly, these symptoms are hard to diagnose and I am now frustrated about all these codes. The car still isn't running right, but it is running okay. That might explain why it idles a little choppy in morning temps up to 60 degrees. Maybe that is why I am smelling a little fuel in the morning? I have been ripped off before on this car. I don't want to get ripped off again. I know what your all thinking. Fix it yourself or buy another car. Idon't know where to start from. I don't believe most mechanics today really know how to fix K cars or really care for that matter. I have experienced this first hand. I am now wondering if I got ripped off by the mechanic that had 30 years experience and rebuilt the throttle body. I am stuck using my classic as a daily driver right now as a full time student low on funds. If I could just fix this problem sensbily and cheaply. I am willing to learn. Please help.

[89ARIES]

Sorry, the code 23 has nothing to do with Throttle Positioning Sensor. It means Throttle Body Temperature Sensor.

[TomChrysler]

Hey Guy!

When was the oxygen sensor replaced last? Sometimes that will cause other components to compensate. Also, check the vacuum lines. I'm finding these cars are highly dependent on vacuum to keep all of the sensors happy.

Don't be fooled by great gas mileage. My Oxygen Sensor was completely dead, and yet I maintained 25 mpg.

Despite the light, your trip to Sacramento should be trouble free. Enjoy your time with your family.

Tom