Technical aspects of automobiles

'94 Safari, location of EGR solenoid and thermo switch

94 Safari, AWD, W engine, PS/PB/AC. Pretty sure I have the 4L60E
trans.

Got three quarters of the way to work the other day when the engine
starts stumbling and wants to stall. Finally realized that something
was upsetting the low idle, causing the oil pressure to drop and the
engine to try to shut down.

Pulled trouble codes 28, 32, and 45.

I removed the EGR valve and found a small piece of carbon-like crud
wedged between the poppet and the housing, preventing the valve from
returning to its closed (?) position. I’m guessing that’s the cause of
this episode.

I’d also like to check the EGR control solenoid and thermostatic
vacuum switch, but where are they?

While I’m waiting for your answer I’ll be trying to re-plug the air
leak through the intake manifold gasket that causes an IAC error and
racing engine. Pulling the EGR valve disturbed the silicone rubber
patch that kept that problem at bay for the last several years.
<sigh>

Thanks,

Mike D.

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posted by admin in Без рубрики and have Comments (4)

4 Responses to “'94 Safari, location of EGR solenoid and thermo switch”

  1. admin says:

    - Hide quoted text — Show quoted text -

    mdev…@eskimo.com wrote:
    > 94 Safari, AWD, W engine, PS/PB/AC. Pretty sure I have the 4L60E
    > trans.

    > Got three quarters of the way to work the other day when the engine
    > starts stumbling and wants to stall. Finally realized that something
    > was upsetting the low idle, causing the oil pressure to drop and the
    > engine to try to shut down.

    > Pulled trouble codes 28, 32, and 45.

    > I removed the EGR valve and found a small piece of carbon-like crud
    > wedged between the poppet and the housing, preventing the valve from
    > returning to its closed (?) position. I’m guessing that’s the cause of
    > this episode.

    > I’d also like to check the EGR control solenoid and thermostatic
    > vacuum switch, but where are they?

    > While I’m waiting for your answer I’ll be trying to re-plug the air
    > leak through the intake manifold gasket that causes an IAC error and
    > racing engine. Pulling the EGR valve disturbed the silicone rubber
    > patch that kept that problem at bay for the last several years.
    > <sigh>

    > Thanks,

    > Mike D.

    Yep that chunk of carbon did it BUT it will do it again as well. I got
    REALLY sick of pulling the EGR on my 94 S-Blazer for the same problem.
    Solved it by getting one of the EGR gaskets with a screen over the
    pintle. Hasn’t bothered since. Another thing you may want to do is give
    that engine a top end cleanup with some GM top engine cleaner. That will
    break up and blow out a lot of the carbon that causes the problem and
    make the engine run cleaner as well.

    Just hit the dealer for a can of the liquid cleaner (not the spray
    version) and follow the directions. DO NOT USE IT INSIDE A BUILDING and
    make sure that the exhaust is aimed away from anything you care about.
    It will be throwing a LOT of carbon and crud out and that stuff will
    stain anything it hits. Oh and when you first start it and run it to
    clear out the cleaner make sure you select an area that is kind of open
    and try to pick a day with a breeze. Your van will be creating a smoke
    cloud like a tank on the battlefield and you don’t want that hanging
    around a long time!


    Steve W.
    Near Cooperstown, New York

  2. admin says:

    I wrote:
    > > 94 Safari, AWD, W engine, PS/PB/AC. … 4L60E trans.

    > > I removed the EGR valve and found a small piece of carbon-like crud
    > > wedged between the poppet and the housing, preventing the valve from
    > > returning to its closed (?) position. I’m guessing that’s the cause of
    > > this episode of stalling and stumbling.

    Steve W. replied:

    > Yep that chunk of carbon did it BUT it will do it again as well. I got
    > REALLY sick of pulling the EGR on my 94 S-Blazer for the same problem.
    > Solved it by getting one of the EGR gaskets with a screen over the
    > pintle. Hasn’t bothered since.

    Ah, that explains the fact we’ve had *brief* problems like this
    before.
    I’ll have to look for that gasket for the next time.

    Never did find where the EGR solenoid and thermostatic vacuum
    switch are supposed to be on this engine, but re-patching the intake
    manifold leak and re-seating the EGR valve a second time eliminated
    the racing engine problem while removing the crud got the low idle
    back to normal.

    > Another thing you may want to do is give
    > that engine a top end cleanup with some GM top engine cleaner. That will
    > break up and blow out a lot of the carbon that causes the problem and
    > make the engine run cleaner as well.

    > Your van will be creating a smoke cloud like a tank on the battlefield

    I’ll have to look into that, Steve. Thanks for the heads-up!

    Be well,

    Mike D.

  3. admin says:

    since you have low oil pressure, check your oil. it might be low.

  4. admin says:

    - Hide quoted text — Show quoted text -

    mdev…@eskimo.com wrote:
    > I wrote:
    >>> 94 Safari, AWD, W engine, PS/PB/AC. … 4L60E trans.
    > …
    >>> I removed the EGR valve and found a small piece of carbon-like crud
    >>> wedged between the poppet and the housing, preventing the valve from
    >>> returning to its closed (?) position. I’m guessing that’s the cause of
    >>> this episode of stalling and stumbling.

    > Steve W. replied:
    >> Yep that chunk of carbon did it BUT it will do it again as well. I got
    >> REALLY sick of pulling the EGR on my 94 S-Blazer for the same problem.
    >> Solved it by getting one of the EGR gaskets with a screen over the
    >> pintle. Hasn’t bothered since.

    > Ah, that explains the fact we’ve had *brief* problems like this
    > before.
    > I’ll have to look for that gasket for the next time.

    > Never did find where the EGR solenoid and thermostatic vacuum
    > switch are supposed to be on this engine, but re-patching the intake
    > manifold leak and re-seating the EGR valve a second time eliminated
    > the racing engine problem while removing the crud got the low idle
    > back to normal.

    >> Another thing you may want to do is give
    >> that engine a top end cleanup with some GM top engine cleaner. That will
    >> break up and blow out a lot of the carbon that causes the problem and
    >> make the engine run cleaner as well.
    > …
    >> Your van will be creating a smoke cloud like a tank on the battlefield

    > I’ll have to look into that, Steve. Thanks for the heads-up!

    > Be well,

    > Mike D.

    On the S Blazer the EGR Solenoid was on the relay strip mounted on the
    firewall.

    It doesn’t take much of a vac. leak to cause the rev. problem.  The
    gasket was available online at Rock Auto and my local NAPA had them as well.

    Steve W.
    Near Cooperstown, New York

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