I am trying to do what I thought was a simple fuel filter change.
However, I am having suprising difficulty determining the fuel
pressure relief procedure on a 97 GMC Sonoma with the 2.2L engine. I
have two manuals which have conflicting methods on this dangerous
work.
The Haynes manual says to loosen the fuel line outlet fitting at the
fuel filter with rags catching the spray. This seems OK, but not very
desirable or safe.
My Chilton manual has four different procedures for the 2.2L alone!
The 1997 has its own method, which says to raise the vehicle, unplug
the fuel pump electrical connection, start the engine and let it run
until it stalls, and try restarting to make sure fuel has been
depleted. This seems far better, except how do you access the fuel
pump electrical connector? There is no access to it since it is right
on top of the fuel pump, which is on top of the fuel tank. With
everything so tightly packaged, I can't see it, let alone unplug it.
It seems unreasonable that to change the filter I would have to drop
the tank. What should I do?
I don't think I can use another procedure, since the Chilton manual is
so specific. Some people say to pull the fuel pump fuse, pull the
fuel pump relay, or even bleed the fuel rail service port valve. If I
pulled the fuse, I would think it would stop the engine before the
residual fuel was depleted, since it also controls the PCM. Pulling
the relay possibly might be detected by the PCM. Finally, I don't
believe I have a test port on my fuel rail, since the fuel pressure
check requires removing the fuel filter and installing a T-fiting with
the fuel pressure gauge. Models other than mine do have a Schrader
valve.
Any ideas? Thanks for your input.
autorepairbot@gmail.com - 22 Aug 2007 02:30 GMT
> I am trying to do what I thought was a simple fuel filter change.
> However, I am having suprising difficulty determining the fuel
[quoted text clipped - 29 lines]
>
> Any ideas? Thanks for your input.
I'm not saying to be careful, but it's gas...not toxic fluid that will
kill you on contact. The rag around the hose trick works just fine.
I've done too many to count like that without a problem.
inboxjm@gmail.com - 23 Aug 2007 20:14 GMT
I did the job just loosening it up and there wasn't any pressure; just
a flow. Although, the truck had been sitting for a day or two. Who
knows what would have happened if I had done it after waiting only 10
minutes. I have changed fuel filters and worked on lines before, so
it's not like I haven't come into contact with gas. I just didn't
want to be caught off guard by any pressure, like some people have.
I'm going to look for the test port to see if it's there anyway.
However, I have my doubts since if it was there, why wouldn't the
Chilton manual use it for the 97-98 2.2L models. They do employ a
test port on the 94-96 and the 99 2.2L models, as well as the 94-99
4.3L models for fuel pressure relief. It seems odd to me. What could
be the difference with the 97 and 98 models that would require two
alternatives? Thanks, as always.