Mechanics

WHAT MAKES A CAR DIE EVERY TIME YOU SLOW DOWN? IT RESTARTS PRETTY QUICK BUT DIES EVERY SINGLE TIME.

1999 Chrysler Sebring • 158 miles

The timing belt broke so had to have heads redone. Now runs good but every time I slow down, it dies. Went to Oreilly's to have scanner tool run on it, but car wouldn't read it so checked the fuses but they are all good.
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SKsilver
June 11, 2012.



First eliminate all vacuum or air leaks in the system. You may have a bad IAC ( idle air control) but try cleaning the throttle body first. Remove the intake snorkel, have someone hold the throttle wide open for you and scrub the back side of the throttle plate and surrounding bore with an old tooth brush and some carb cleaner. Be sure to spray some into the small holes next to the throttle plate. That should help stabilize the idle. If it still has a problem, replace the IAC

Wrenchtech
Jun 11, 2012.
Thank you, I will try that.

Tiny
SKsilver
Jun 11, 2012.
Hey guys. Excuse me for butting in but there's an easy fix for this one. Most likely the battery was disconnected when replacing the timing belt. That means the Engine Computer lost its memory and has to relearn "minimum throttle" before it will know when it has to be in control of idle speed. Until that happens you also won't get the nice idle flare-up to 1500 rpm at engine start up.

To meet the conditions for the relearn to take place, drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the brake or gas pedals.

Caradiodoc
Jun 11, 2012.
Okay I'll try that but I drove 40 highway miles yesterday and it still did it and let it sit for 3 hours then drove it again in town and it still did it.I'm getting ready to try it today.

Tiny
SKsilver
Jun 11, 2012.
"coast for at least seven seconds without touching the brake or gas pedals".

That is not a normal driving condition except for leaving the highway on a long exit ramp or coasting down a long hill. That's why it's often necessary to consciously do it.

What Wrenchtech suggested can happen any time. What I suggested is most likely to occur right after some other service was performed that required the battery to be disconnected.

Caradiodoc
Jun 11, 2012.
Thank you for your advice, I will definitely try it.

Tiny
SKsilver
Jun 12, 2012.
Another possibility is that the belt is out of time too, depending on how good it runs the rest of the time.

Wrenchtech
Jun 12, 2012.
It runs pretty good rest of the time, but sometimes it acts like it's missing out. Sometimes it restarts on first try and sometimes it takes 2 or 3 times and sputters. We changed the IAC sensor and that seemed to help a little. We're going to check the fuel filter to see if it's clogged.

Tiny
SKsilver
Jun 13, 2012.
We think it also could be the throttle position sensor so we're going to check that too.
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Tiny
SKsilver
Jun 13, 2012.
Except for diesel trucks you will never solve a running problem on a Chrysler product by replacing the fuel filter.

Are you guessing at the throttle position sensor? That's the most expensive and least effective way to diagnose a problem. They typically cause a hesitation on acceleration but the momentary dropout in its signal will be detected and a fault code will set in the Engine Computer. That will turn on the Check Engine light.

Sputtering and intermittent hard starting but it does start eventually, then run okay suggests a fuel supply problem but that is not the way Chrysler fuel pumps generally fail. A much more effective way to diagnose this kind of problem is to drive it with a scanner connected that can display and record live data. You press the "record" button when the problem occurs, then the scanner records a few seconds of sensor data. Since that data passes through the scanner's memory, the recording actually starts a couple of seconds before you pressed the button. Later the data can be viewed slowly to see if the Engine Computer reacted to a glitch in a sensor's signal, and you can see which sensors reacted to a change in operating conditions. Experienced mechanics can diagnose a lot with that information. The rest of us are just shooting in the dark and guessing. Every time we do that and install another new part, we introduce another new variable that the computer has to learn.

Caradiodoc
Jun 13, 2012.
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