On Sep 3, 9:51 pm, "Jean Castonguay" <jcast...@[EMAIL PROTECTED]
> wrote:
> It starts easily at any temperature, even on a very cold Qu,bec
> winter.
>
> It runs smoothly, almost always...
>
> Very seldom, it hiccups for a second or two while I drive at regular
> speed; the phenomenon is so short that the car does not seem to loose
> speed; the inertia restarts the engine. Fortunately, it has never
> occurred while I was overtaking another vehicle!
>
> More frequently, but not very frequently, it stalls while I am stopped
> at a red traffic light. Then I have to use the starter for 10 to 20
> seconds before the engine restarts. The starter works flawlessly; I
> changed 2 of its 4 brushes and I regreased last summer.
>
> I read the Engine Control Module codes; I got two.
>
> One is related to the Engine Coolant Temperature Sensor. I am prone
> to discount it because the problem occurs at any engine or ambient
> temperature.
>
> The other, OBD II P1355, is related to the Crankshaft Position Sensor
> Reference.
>
> Today, I disconnected the Crankshaft Position Sensor Reference and
> Injector Sub-Harness. This connector is almost on the top of the
> timing chain cover, and the harness it connects to runs along the top
> of the timing chain cover. This connector was very clean inside.
>
> I measured the Crankshaft Position Sensor Reference resistance at 540
> ohms which is OK since it should lie between 470 and 570 ohms. I also
> checked that there is continuity between pin 7 and the engine.
>
> I have yet to check that there is continuity between pin 3 and both
> pins 44 and 48 on the Engine Control Module. Is there a way to reach
> this ECM connector without taking the whole dashboard apart?
>
> As I see it, it is either the sensor itself or a intermittent in the
> wiring. I am afraid it will be difficult to find because the problem
> occurs so infrequently.
>
> I thank you very much in advance for any help.
> --
> Jean Castonguay
> lectrocommande Pascal
Your diagnosis is very thorough, but I fear, in one aspect at least,
incorrect.
When the coolant temp sensor is faulty, the engine computer thinks the
car is cold when it's not. Because of that the computer will adjust
the feul maps and make the car run rich.
Running rich leads to bad gas mileage, lower power, and perhaps even
un-relaible low rpm operation.
You may have noticed it already. Is your temp gage slightly low? Car
doesn't quite feel as powerful as it used to?
Change the coolant temp sensor. Once you do, it may take 2 or 3
tankfulls for the car to re-adjust to the new readings.
CD
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