The EGR mounting surface gets VERY hot, so just use the gasket that comes
with the new EGR valve. If the surfaces are clean and not rusted, you
don't need any goop on the gasket, and most such goops can ruin the O2
sensor unless they are specially formulated to be O2 sensor safe.
Any air leak which allows air to enter the intake manifold without passing
the air flow sensor will befuddle the computers into making the car run too
lean. This can cause valve problems if not corrected soon. Usually, this
is not a problem because the car, if it runs at all, will run so poorly that
no one would drive it that way. The usual mistake is leaving the lid clamp
off the air cleaner, but this is only one of many places where air can sneak
in there. Don't forget the various vacuum connections to the intake
manifold -especially the power brake booster and the PCV valve, either of
which can develop a major leak - those are BIG hoses!.
The heated air duct is relatively unimportant as a source of air leakage,
because the air has to go past the air flow sensor whether it is heated or
not. Lack of heated air will definitely affect cold running, though, so
leave it in position.
There have been a couple of reports of these cars acting badly if there is
any disturbance to the backpressure from the exhaust system, either too low
or too high, but I have not had an example to experiment with, so I can't
confirm these reports.
Dick Benjamin
----- Original Message -----
From: "Kurt Piepenburg*" <trukkcp@xxxxxxxxxxxxxx>
To: <mailing-list@xxxxxxxxxxxxxxxx>
Sent: Thursday, January 16, 2003 5:29 PM
Subject: IML: EFI air leaks 81-83
>
> I wonder...what air leaks have EFI owners found to be the most troublesome
to
> find and correct? What were the fixes? Personally, I've had the loose air
> cleaner (self-induced) and also a ripped heated-air duct snorkel. Those
were
> easy to fix. Exhaust leaks have caused performance problems as well. It
seems
> that the HSP, if not seated properly on the manifold spacer, or not
torqued
> properly can cause issues as well. From what I've learned about my car
over the
> years, the system must be airtight so as not to cause mixture problems.
The
> recent issue in regard to the EGR seating is interesting. Would it be a
good
> idea to use a gasket sealer when replacing? Any input would surely help
just
> about everybodywith EFI in future, especially those who are "new" to it.
> 81 black/heather for sale
>
>
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