Date: Sat, 2 Feb 2002 14:47:26 -0800
Reply-To: Aaron Robinson <kleinboy@MAC.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Aaron Robinson <kleinboy@MAC.COM>
Subject: Fuel pump shutting off???
Content-Type: text/plain; charset=US-ASCII; format=flowed
I've been working on figuring out why my van lurches at 2900-3000 rpm
for a while now. I've begun to suspect the fuel pump recently since in
the last 2 days, the van has shut down 2 times (These are the first 2
times it has done this). I'll be going along, hit ~2900 rpm, it lurches
and then I loose all throttle response and have to pull over. The tack
is working, all lights on etc. Just no throttle response. If I try to
restart it, it won't. I can't hear the fuel pump when turning the
ignition key when it does this. Then if I wait a few minutes, rattle the
floor a little etc. all of a sudden I hear the pump when I turn the key
ad it starts/runs fine (except the lurch is still there). I don't think
that it's my ignition switch since no matter what I do with the switch I
can't reproduce the symptoms. I also can't decide if the fuel pump issue
is the cause of my stumbles or just a symptom that is somehow caused
when it starts hesitation/jerking.
What is the best way to figure out an intermittent problem relating to
the fuel pump? Would this most likely be the pump's mechanical condition
or something electrically somewhere else? How should I check this?
Also, I have noticed that 99.9% (I can't rememer if it is 100%) of the
time the lurching doesn't happen with the first cold start of the day.
It will do it's lurch...always at 2900rpm...most of the time once it's
been warmed up for the day. Even if it sits for long enough to cool down
(an hour or two). Basically lurch doesn't happen when it is cold, but
happens most of the time when warm. I can get it to hesitate at idle too
when working on the van. If i rev it up to 2900, it starts to hesitate
and won't pass through 2900 rpm even with me continuing to give it more
gas...the rpm's gom up and down fairly rapidly from 2600-2900, but don't
rise in conjunction with the throttle being opened until it's been
opened up a lot. Then it revs up high and it fine there. I can even feel
it stumble on deceleration when it passes the 2900 mark. There's no
difference with the OXS connected/disconnected.
Just for your info here is what I have done so far.
- New cap/rotor/plugs/wires
- New OXS
- AFM Wiper board moved so the arm moves on new carbon track (smoothed
out my idle a lot)
- All grounds cleaned
- Reset timing and idle
- Checked distributor to look for problems with wear (John Clavin fixed
his hesitation/stumbling after replacing the distributor...thanks for
the help John!)
Where should I go from here? I don't want to use the "throw-parts-I-
can't-afford-until-it-works" solution on this. Basically unemployment
doesn't pay *that* well.
Thanks, Aaron
'85 vanagon 1.9L 250,000 miles (~150K on engine, 20K on heads)
=================================\
This is my original message
=================================
Hi all. I have a problem with my '85 vanagon that seems to be getting
worse with winter.
History
----------
Last winter, my vanagon developed a severe "hiccup" when I was cruising
at 2900 RPM. It doesn't do it all the time, but it does it a lot now
that it's not summer. During the summer it is not nearly as bad, but it
still will do iton occasion. What happens is when the tachometer is
passing 2900 RPM it will give a terrible sounding and feeling lurch. If
I'm accelerating hard, it will usually just do it once assuming I pass
through 2900 RPM quickly.
If I'm trying to cruise at 2900 RPM (any gear) it will continue
lurching.
It doesn't occur at any other engine speeds.
