Mechanics

ERRATIC IDLING

1995 Chrysler Concorde

Shakes or Wobbles problem
1995 Chrysler Concorde 6 cyl Front Wheel Drive Automatic 67000 miles

Car starts fine then if I rev it up slowly it starts erratically climbing, when I put it in gear it backfires repeatedly through intake and is very hesitant also cruise control light flips on and off as does the check engine light when in motion. Died once at parking lot speed.
it ran fine yesterday, I changed oil last night using mobil 1 10w30, a fram high mileage filter and lucas oil stabilizer I put a little over 5.5 quarts including oil stabilizer. Started it after oil change and drove to store it was fine then, but today is when problems started.

car has 3.5l engine and abs

23 0ct 08
i was just informed about turning the key on and off 3 times and keep it on the last time and the check engine light flashed as follows 1.2.4.3.5.5

25 Oct 08
replaced ignition coil pack still same problem

31 Oct 08
had a mechanic spend four hours going through it and replaced fuel filter and spark plugs no positive results car acts the same. The mechanic was completely stumped as to what is wrong getting no codes and everything seemed fine by scanner and checking all vacuum lines and all connections.
(scanner says car is okay to drive) mechanic thinks either computer is bad or timing is off slightly (doubts timing because car runs to smooth at idle, startup and killing seems normal).

01 Nov 08
today car overheated, I think the thermostat froze shut is it possible that my whole problem can be vapor lock or a cooling problem? Will replace thermostat and coolant temp sensor tomorrow.
Avatar
Rebtxn
October 22, 2008.




Hi,

Code 12= Battery disconnected in last 50 starts, or module power lost
Code 43=Cylinder misfire or ignition coil circuit.
Code 55= end of test, or IAC not moving properly.

Check power and ground to battery and PCM, also test fuel pressure.

Go here and checkout our video.
http://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Merlin2021
Nov 2, 2008.
Fuel pressure has been checked and is 40 at idle 49 when car is off and between 800 rpm (idle) and 1700 rpm gauge jumps between 40 and 50

Tiny
Rebtxn
Nov 2, 2008.
Look OK but test the pressure regulator as shown, and test the injectors with an ohm meter reading should be 12 ohms on all of them.

If you can narrow down which cylinder is misfiring, there are tests for the wiring to the PCM for each cylinder. If it backfires all the time when accelerating, the camshaft may be worn.

Merlin2021
Nov 3, 2008.
Haven't tested injectors but I replaced thermostat and coolant temp sensor and the car has no miss and runs smooth and perfect now took on a 20 mile drive with my bro inlaw following me up hills and down and car didn't have so much as a hiccup.
Outta curiosity I will test injectors though. Thank you for your timely responses.
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Tiny
Rebtxn
Nov 3, 2008.
If it's running smoothly, my old saying is if it aint broke, dont fix it!

Merlin2021
Nov 7, 2008.

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