Question1995 Chrysler Cirrus 4S
On sporadic occasions, there is no response when the accelerator is pressed. If forced, the car will sputter, backfire and simply not move. If you gently manipulate the pedal, you will find the "sweet spot" and it's fine - for a couple of minutes. Then it begins again. It seems that after the car has warmed up, the problem will go away - and not show up again for a few days.
The main computer and the harmonic balance have been replaced recently. It ran fine - until this morning - but it righted itself after a couple of miles.
I have a wonderful mechanic who is as stumped as I am. No lights come on when this happens and when he puts it on the diagnostic machine, there are no codes. It took several days to diagnose the harmonic balance because the car would not misbehave. I'd greatly appreciate your brilliance.
AnswerHi Brenda.
"Brilliance" is a challenge.
Unfortunatley, the symptom sounds like "hesitation/sag/stumble" in Chrysler troubleshooting manual parlance, and that one lists all 17 areas of potential problem as relevant.
Because there are no codes it suggests a component is out of calibration to a degree that is too minor to trip a code set. Because you say it goes away when the car warms up I would wonder whether the coolant temperature sensor (or the intake air temp sensor, though less likely) might not be reading inaccurately (that is checked with an ohmmeter and a thermometer, placing the sensor in a heated water bath). Another suspected area would be a sticky EGR valve particularly if the problem also manifests itself as rough idling; if not then that probably is not the reason for your hesitation.
If you see a predictable pattern of occurence, it would be more likely for the mechanic to have success if you can arrange for its occurence when you are close to the shop so he can see it when it is doing it.
I can list the 17 tests shown in the manual, but it is so extensive that maybe just listing the first 6 will provide some direction: secondary ignition and timing, pcm (computer) power and ground circuits, engine vacuum, fuel pressure, coolant temp sensor, and throttle position sensor (note that one beause you speak of a sweet spot in the pedal position which could be the manifestation of a minor discontinuity in the variable resistor that constitutes this particular sensor, which if present would cause a stumble).
So my thoughts are along the lines of those 3 sensors and the egr valve beginning to stick.
I am always interested in knowing the resolution of these quandries. So let me know.
Roland
