Question about 1990 Jeep Wrangler

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1990 Jeep Wrangler Islander L6 4.2L

What is the correct timing for the Jeep? And what is the correct choke settings for it, too?

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9 Degrees 1990 Jeep Wrangler Islander L6 4.2L - clearpixel.gif Application: With automatic transmission
With Federal emission
16 Degrees clearpixel.gif Application: With automatic transmission
With high altitude emission

9 Degrees 1990 Jeep Wrangler Islander L6 4.2L - clearpixel.gifg src="" alt="clearpixel.gif" class="h_mi" /> Application: With manual transmission
With Federal emission
9 1990 Jeep Wrangler Islander L6 4.2L - clearpixel.gifes clearpixel.gif Application: With manual transmission1990 Jeep Wrangler Islander L6 4.2L - clearpixel.gif With Federal emission


Posted on Jan 29, 2009

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  • Nate Stansfield
    Nate Stansfield Jan 29, 2009

    Before top dead center
    *Set at warm idle speed (700 RPM)
    *Distributor vacuum hose disconnected & plugged
    *Transmission in neutral (parking brake engaged)
    *All accessories off

  • Nate Stansfield
    Nate Stansfield Jan 29, 2009

    To adjust the carburetor on the 4.2L engine, the carburetor choke
    and intake manifold heater must be off. This occurs when the engine
    coolant heats to approximately +160ºF (71ºC).

    Measure the distance between the air horn wall and the choke plate. If it is not 9/64 in. (3.6mm), bend the choke vacuum break to adjust the clearance.

    Choke Setting
    The automatic choke setting is made by
    loosening the choke cover in the desired direction as indicated by an
    arrow on the face of the cover. the original setting will be
    satisfactory for most driving conditions. However, if the engine
    stumbles or stalls on acceleration during warm-up, the choke may be set
    richer or leaner no more than two graduations from the original setting.

    With the throttle held fully open, apply pressure on the choke valve
    toward the closed position and measure the clearance between the lower
    edge of the choke valve and the air horn wall. The measurement should
    be 9/32 in. (7mm). Adjust by bending the tang on
    the throttle lever which contacts the fast idle cam. Bend toward the
    cam to increase the clearance.

  • Nate Stansfield
    Nate Stansfield Jan 29, 2009

    If you want more info, you can go to this link for FREE ONLINE SERVICE MANUAL for your jeep. (copy and paste in your address bar)



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