Date: Tue, 31 Aug 2004 17:08:27 -0700
Reply-To: Craig Oda <craigoda@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Craig Oda <craigoda@GMAIL.COM>
Subject: Re: 28.8 MPG
In-Reply-To: <!~!UENERkVCMDkAAQACAAAAAAAAAAAAAAAAABgAAAAAAAAAxnoaoed5TE2gAUzkZf1Rt8KAAAAQAAAA6QdRUj231UiLzACLD4lHLQEAAAAA@cox.net>
Content-Type: text/plain; charset=US-ASCII
Robert,
thanks for this post. I have some questions for the rest of the
vanagon community and to Robert too, if he has any time.
About a month ago I took apart my throttle body and that hollow metal
thing that connects all the intake manifold pipes (I guess this is
called the air center plenum?)
What gaskets on the throttle body did you replace? I saw a gasket
between the throttle body and the air plenum, about 2 1/2" in
diameter, round, and about a 1/2" wide and maybe a few mm thick. Mine
was kind of hard. Is this thing supposed to be soft? I put some
silicone rubber on it and it seemed to smooth things out.
My intake boot "big one" that connects the air filter and the throttle
bottle might also need replacing, but it costs over $70, so I'm
waiting on that. I can't detect any leaks or cracks in either of the
two seals on the throttle body. It's really hard to isolate the
vacuum leak. Especially since it works okay (not great, but pretty
good) ever since I took apart the air intake system and reassembled
things. I'm spraying chemtool around and not hearing any change in
idle.
I was thinking that my air plenum was leaking too. I'm still not sure
because I also resealed the gaskets when I swapped out the air plenum
for another one that I had lying around the garage.
Also, do you think I'm screwing up my O2 sensor since I put silicone
rubber gasket sealer on the gasket between the throttle body and the
air plenum?
Do you think that the fuel injector seals are important? Mine are
slightly cracked.
-- Craig
On Tue, 31 Aug 2004 15:47:38 -0700, Robert Lilley <rclilleyjr@cox.net> wrote:
> Well, I finally got around to replacing my air plenum, throttle body, air
> runner gaskets, FI seals, setting back timing to stock setting and fixing
> fuel leak in one line (previously unknown), ADDED 4 missing clamps for the
> idle speed control valve circuit; Two on the rubber tube and 2 on the
> grommet on the center plenum and ISCV.
>
> I took the throttle body apart cleaned, replaced the seals and Set the gap
> on the switch. I put on a used newly painted center plenum, replaced the
> gaskets under the air runners added new seals and added clamps that were
> missing. While looking at ETKA, I noticed that there were clamps on the
> ISCV circuit. Mine had none, so I ordered some.
>
> I went for a 55 mile drive. About 10 miles were in city traffic the rest was
> on highway going ~65. I filled up just prior to taking the trip and it
> lasted @1 hour in 100+ heat in Mesa AZ. I filled up immediately after
> stopping the trip. Starting on a full tank and then filling back up it took
> 1.9 US gal. While this is no means scientific, many more miles need to be
> run, it is just nice to finally get the mileage back up.
>
> I did not use AC it is soon to be fixed, I did not rev the engine high, just
> normal take offs. I used barely any pedal to keep going 65+. The Digifant
> FI is not a "racing" FI system but a "cruising" one.
>
> Next project is the A/C along with cooling system flushing and some minor
> parts replacing.
>
> This is with a modified WBX engine.Cam, crank, ECU chip, ratio rockers,
> exhaust, intake, etc.
>
> PS When I first put my modified engine in, I was having a noticeable whistle
> when I first opened the throttle. I replaced gaskets and rebuilt the
> throttle body, chased a lot of things but the whistle was still there.
> Finally after changing the throttle body and center air plenum it has
> virtually disappeared. Do not know if it was the throttle body or the
> center plenum. I would suspect the center plenum because there is nothing
> physically wrong with the throttle body I can detect. The shaft is tight,
> seals are new and soft, no defects that I can find.
>
> PSS If you do not believe me, come and let's go for a ride.
>
| 
