Date: Wed, 24 Apr 1996 19:47:34 -0600
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: Dave Backe <backed@cadvision.com>
Subject: 77 fuel injection - glorious end to Chapter 1
OK. So my newly installed fuel injection system is running way too rich, and
gas was forming around the tap for the pressure gauge, and around some of
the hose connections. Hmmm. "It's gotta be the pressure regulator," I think
to myself. Running rich, and too much pressure; one solution to both anomolies.
I know.. I should get a fuel pressure gauge and make SURE the pressure is
too high, and also check the return fuel line from the pressure reg, just to
be sure.
I cheated. I replaced the pressure reg first. Hey, I've been a backyard
mechanic for almost 2 months now (that's how long I've had my bus). So what
if this is the first mechanical thing I've ever done in my life. I KNOW how
this thing works... I pulled the tank return line from the p.r. Gas came
out, so the return line probably isn't clogged. Good. I plug the line,
loosen the locking nut, and go back up. Try and loosen the the hose clamp on
the high pressure side of the p.r. - hard to get at. Maybe if I unplug the
7-pin connection to the air flow meter I can get at it better. Yup. Take out
the old, put in the new, reconnect the gas lines and fire it up.
Yay! No more black smoke. The idle is a bit high, but as she warms up, the
idle seems to come down in steps. Still a bit high, so I tighten up the idle
adjust screw a bit. Still seems kinda rough, but nowhere near as bad as
before. Sounds better too. No gas forming at the tap or hose connections.
Despite my cockiness, the fuel circuit seemed to be operating a lot better.
I lucked out.
I hit the accelerator on the throttle body. It tries to rev, and eventually
does, but runs real rough. I also hear a faint hissing, like air flowing -
probably a small air leak. Try to rev it up again - coughs and eventually
works its way up, but its REAL rough. Probably the timing.
I shut her down, loosen the distributor, get out the timing light and start
her up again. Whoah! At idle (~900rpm) it's over 20deg btdc. OK, lets bring
'er back to 7.5. OK, that's better. I push the throttle lever, and it still
gags. Hmm. I'm thinking "hey, I've got this much accomplished today - let's
give it a rest until tomorrow". Still hear some faint hissing. Shut it down
again, and really tighten down the air and vacuum connections. Tighten up
the screws that connect the throttle body to the air intake dist.
Wait a minute. What's this? Gee! Maybe I should have reconnected the 7-pin
connector to the air flow meter!!!!
Duh..... I'm surprised it even ran without it. I plug it in, check a few
more air hoses, and start it up.
Aaaahhh... That's the sound I'm looking for. A lot smoother.... I step on
the gas, and it revs up like it should.
A quick check for gas leakage, and I start packing my tools into the bus
while it's idling. It's still a faint bit rough, but in a knitpicking kind
of way; my '91 fuel injected car idles a bit rough too. I think it smells a
bit rich, but I'll have to see what happens over time. Off to SuperFLAPS;
it's a bit farther away than FLAPS, but it will give me a chance to test 'er
out.
Wow, this thing has a totally different power curve than the Weber. The
Weber gives a good punch once it hits about 1500 - 2000rpm. The problem with
the carb, though, was that it had NO power up to that point; hit the gas and
watch it die. Especially bad at air temps below 50deg F. Don't even try to
start moving while stopped on a hill.
But now... It's about 45F this evening. And I have power at low RPMs! What a
feeling to be able to take most turns in 2nd gear. To not have to wait 2
seconds after stepping on the gas to get the RPMs up high enough to release
the clutch and start off.
Happy, happy... Joy, joy....
I arrive at superFLAPS, check for fuel leakage, and grab some fi cleaner gas
treatment stuff (they didn't have Techron, so I grabbed STP. I may need a
couple of 'treatments' anyways, so I'll look for the good stuff in the
meantime). Head to gas station and put in almost a full tank of premium, and
head for home. Still want to check for any more air leaks, but it's running
better than ever.
I am injected.
Thanks to everyone for their support and suggestions. I don't think I would
have tried something like this without the help of this massive resource.
I learned a lot over the last month. Not just about fi systems, but about
how to do things yourself. This whole 'disposable society' thing is the
reason I wanted a bus in the first place. An 'immersion course' in
automechanics; an immersion course in life, if you will.
The end.
Stay tuned for "why does my transmission go 'clunk'" and "the never ending
pushrod tube leak", coming soon to a theatre or drive-in :) near you.
Dave.