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Followup To
Question -
I replaced the plugs/wires and pcv filter on my sundance. Now its not running right and I cant figure out why. I can start it up and go with no problems but if I shut the car off and start it up again it has a rough idle and hardly any power. I've checked all the connections and everything seems to be in place. Could the cause be a wrong firing order? The car recently had the cap/rotor and fuel filter replaced but I didn't have any trouble until I replced the plugs/wires and pcv filter.
Thanks
Dan
Answer -
Hi Dan,
I might be able to do better if you could tell me which engine you have. I assume it is a 4 cyl, but which displacement and is it a turbo?
Also, are you saying that if you start the car from cold it runs fine, runs fine when its warm, and then if you turn it off and restart it immediately it will then rough idle and no power? Or does it have to cool down for a while (how long?) before it has a hard time starting up? How long or to what temperature must it cool down before is it back to normal operation? And finally, when it has trouble idling and having power, does it ever get any better than that as you drive it?
It makes me think it is a temperature sensor problem, but for that I need to know more about which engine.
Have you tried asking the engine controller for any fault codes it may have noticed and logged? You can get those with the ignition key: "On-off-on-off-on" and leave the switch in the On position (do this switching routine in less that a total of 5 seconds). The watch the check engine light which will be "on" to begin to flash, pause, flash, pause, etc. Count the number of flashes before each pause, then repeat to make sure you have count correct. Then group the numbers in pairs in the order of readout to form two digit numbers, the last of which will be 55 which is the code for "end of readout". Tell me any other numbers that readout before the 55.
Roland
Hi Roland
Thanks for answering. The engine is a 2.2 single injector non-turbo. To answer some of your questions: The car will run fine until it warms up, then it starts with the power loss and a gentle "bucking" (for lack of a better word). It will not return to normal until it has cooled down completely and gets no better as I drive it. The engine will rev as it should with the car in neutral. The problem only occurs when the transmission is engaged. The car returns no fault codes and I know the check engine light is functioning properly. Today I hooked up a fuel system pressure guage and got no drop in the pressure at anytime, even when the car is hesitating and experiencing power loss. Next I bypassed the EGR valve which also had no effect. Hope this info helps, I'm puzzled.
Thanks again,
Dan
AnswerHi Dan,
I would suspect the coolant temp sensor that is located on the side of the thermostat housing (between spark plug 3 and 4)for possibly being out of calibration, but not so badly as to set a code. Take the plug off of it when the engine is cold and see if it reads 7,000 to 13,000 ohms, then reconnect and drive the car until it acts up and the temp gauge reads 1/2 to 3/4 which would indicate that the coolant is now near 200 F. Stop and disconnect the plug again and see if the resistance has dropped to the range of 700 to 1,000 ohms. If it has not, then replace the sensor.
Also, check that the tan/black sensor wire is connected to pin 2 of the 60 way connector at the engine controller using an ohmmeter to test that it is 0 ohms. Pin 2 is the second from the left hand end of the top row of pins as you hold it with the pins facing you and the short tab up. Also check the the black/light blue wire of the connector is attached to pin 4 of the 60 way.
The main thing that has to change as the engine warms is the mixture which has to be leaned out, and that temp sensor is responsible for telling the controller how things stand temperature-wise. So try those tests first.
Roland
