When engine is cold and first started, it runs.

Tiny
ANONYMOUS
  • MEMBER
  • 1986 NISSAN HARDBODY
  • 150 MILES
When engine is cold and first started, it runs VERY rough for 5 minutes. I have to sit and keep the idle high. Lots of whitish smoke exits. Once it warms up, it runs smooth and there is no noticeable smoke. I have replaced the O2 sensor and the Coolant Temp Sensor, but there is no change. Could some kind of vacuum hose leak account for this? Any other ideas?
Thursday, October 25th, 2012 AT 6:13 PM

5 Replies

Tiny
KHLOW2008
  • MECHANIC
  • 41,815 POSTS
The cold start system is not functioning correctly. Are there any trouble codes?
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Thursday, October 25th, 2012 AT 6:21 PM
Tiny
MARLONFURTADO
  • MEMBER
  • 2 POSTS
I'm not sure how to obtain trouble codes.
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Friday, October 26th, 2012 AT 3:12 PM
Tiny
KHLOW2008
  • MECHANIC
  • 41,815 POSTS
Refer to diagrams.

SELF-DIAGNOSTIC SYSTEM DESCRIPTION

The self-diagnostic system determines malfunctions of signal systems such as sensors, actuators, and wire harnesses based on the status of the input signals received by the ECC control unit. A malfunction is displayed by both the Red and Green LEDs (Light Emitting Diodes).

Basically, self-diagnosis is always performed when the power is furnished to the ECC control unit. The self-diagnosis results are retained in the memory chip of the ECC control unit and are displayed only when the diagnosis mode selector (located on the side of the control unit) is turned to "ON".

The self-diagnosis system is provided with functions which display malfunctions being checked as well as those which are stored in memory. In this sense, it is very effective in determining an "intermittent" malfunction. The results which are or were stored in the memory can be erased by following steps specified.

A malfunctioning area is determined by the number of flashes of both the Red and Green LEDs. First, the Red LED flashes and the
Green follows. The Red LED refers to the tenth digit while the Green one refers to the unit digit. For example, when the Red LED flashes three times and the Green LED flashes twice, this implies number "32". In this way, all problems are classified by code numbers.
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Friday, October 26th, 2012 AT 3:53 PM
Tiny
MARLONFURTADO
  • MEMBER
  • 2 POSTS
What LED's am I to look for? To find trouble codes do I turn the key on & off a specific number of times and then watch for something to light up on the dash? Do I actually turn over the starter each time or simply get the dash lights to come on? Do I do this rapidly or slowly?
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Friday, November 9th, 2012 AT 6:18 AM
Tiny
KHLOW2008
  • MECHANIC
  • 41,815 POSTS
The LED on the small window of the engine computer.
You only turn the ignition to get the dash indicators lihts to come on, without starting engine.
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Friday, November 9th, 2012 AT 4:25 PM

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