Mechanics

RUNNING ROUGH AND STALLING

1999 Plymouth Voyager

Engine Mechanical problem
1999 Plymouth Voyager 6 cyl Front Wheel Drive Automatic 66,000 miles

My 1999 plymouth grand voyager has two problems. First at times in the cold weather it will run rough when I star it up. Not all the time though. I will have to have it up to 2,000 rpm for a couple of minutes to run right. Second it will die when it is warm when slowing down at times the rpm will go 1000 to 500 to 1000 & 500 and die. This stalling is smooth on the speeding up and down of the engine. I have cleaned all grounds and added a new groung from the motor mount to frame. The plugs are ok. The computer and coils and module have been changed in the past from chrysler said the previous owner. I had this hooked up in cold weather in a computer and found nothing. It ran fine that day. There is no codes but had 29 previous codes that were erased. The idle air moves up when the computer tells it to. The map sensor seemed ok too. It was around 2 degress F and the temp sensor said 7 0r 8 volts. What would this reading be in F? Do you have any ideas before I change stuff out? Every time the engine stallls it starts right up. The fuel pressure checks out ok too.

Thanks

Larry
Avatar
Desperadol30
December 24, 2008.



SURGING
Check the following:  Check secondary ignition system.
 Check PCM power and ground circuits.
 Check engine vacuum.
 Check fuel pressure.
 Check Engine Coolant Temperature (ECT) sensor calibration.
 Check Throttle Position (TP) sensor calibration.
 Check Manifold Absolute Pressure (MAP) calibration.
 Check minimum idle airflow.
 Check oxygen sensor switching.
 Check Idle Air Control (IAC) motor operation.
 Check evaporative system.

[quote] It was around 2 degress F and the temp sensor said 7 0r 8 volts. What would this reading be in F?[End quote]

IAT sends resistance value, not voltage. You need to perform the test again. This time use resistance (ohm) mode, instead of voltage. Ambient temperature of 70 degrees F, your reading should be around 7000 - 13000 ohms. At normal operating temperature, it should read between 700 - 1000 ohms.

But based on your description, I am inclined to say either vacuum leak or EGR transducer problems.

Tiny
Zackman
Dec 24, 2008.