Date: Sat, 24 Jul 2010 21:19:19 -0400
Reply-To: Mark <mbrush@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Mark <mbrush@GMAIL.COM>
Subject: Re: stalling and hard restart
In-Reply-To: <016001cb26e0$87139b50$6401a8c0@PROSPERITY>
Content-Type: text/plain; charset=ISO-8859-1
Thanks for all your thoughts on this problem. Just reporting back to say
it's been fixed. Turns out I had two bad relays (fuel pump relay and the
ecu relay). Once both were replaced, the stalling and hard restart problem
cleared up. 20 years is a long time for those relays to work - pretty
impressive, actually. And I figured out why I was hearing what I thought
was the fuel pump run continuously when I just replaced the fuel pump
relay. It was actually engaging the idle stabilizer faster than my old
relay, so I mistook the idle stabilizer buzzing for the fuel pump buzzing.
All cleared up now - on to the next thing (cleaning gunk under the luggage
rack and putting little screens in the drain holes - that should be fun)
Mark
On Sun, Jul 18, 2010 at 9:20 PM, Scott Daniel - Turbovans <
scottdaniel@turbovans.com> wrote:
> If you are 'sure' that the thing that keeps it from firing up is lack of
> fuel pump running ...
> you're on the right track with the fuel pump relay ..
> though if your used one made the fp be on steadily ...that's sure not
> right.
>
> IF ...it is simply a matter of fuel pump control...no parts like oxygen
> sensor etc are involved..
> Listening for the fp to pre-run is a very good habit. I do that every time
> I fire up any vanagon.
>
> there are only a few requirements to make that happen ..
> power to the ecu, and ecu supplies ground to the fp relay to energize it,
> to run the fuel pump.
> power for the fuel pump comes from the main relay I believe ....consider
> that part.
>
> if nothing else, at least to sort through the weirdness, I'd rig a manual
> fuel pump switch temporarily ..
> so that you can get 12 V to the fuel pump 'for sure' .
>
> if it's as simple as no power to the fuel pump ...that shouldn't be 'too
> hard' to fix.
>
> if it's something else...say pump runs but there's not suffecient fuel
> pressure, that's anohter story of course. I like to have a fuel pressure
> guage on them while sorting through stuff like this. Currently I have on
> between the front seats, but running fuel through the van like that is a bit
> scary ..
> and the engine cover doesn't close perfectly ....and heat gets in the
> cabin, but by golly, I am sure there is fuel pressure on this one van with
> an intermittant igntion problem.
>
> it would be nice to have another ecu. I have heard of one that would not
> supply ground to energize the fuel pump relay, but only one. Usually they
> are very good about that.
>
> if you are sure the pre-run feature is not working ....just work on that
> and it shouldn't be that hard to track down.
> once past the pre-run feature, , the next time the fuel pump runs is during
> starter cranking ..
> and ecu knows the engine is cranking due to seeing ignition ..
> like if you take another distributor and plug it into your harness, turn on
> your key, and turn that distributor with your fingers, you should hear the
> fuel pump run then too. That's a nice test to do ..
> shows that the entire fuel pump control circuit is working. When I see
> fuel pressure also during that test, then I know that whole part of the
> system is working like it should.
>
> seems to me that if the fuel pump won't pre-run, and it won't run during
> cranking ...
> and you are sure it's not pump or electrical connections for it ...
> my mind goes to the two relays and the ecu.
>
> I believe in redundency for the sake of not getting stuck anywhere, and so
> far I have not had to arrange a back up fuel pump power supply ........but I
> sure would for any excuse .
> As far as I am concerend they should have two complete redundant and
> indepedent fuel pump power supplies, plus manual back up.
>
> the two relays are identical I think.
> and it is amazing how many of these 20 year old relays work so reliably.
> wouldn't be a waste of money to one or two high quality new ones in hand.
>
> I wouldn't dismiss the igntion switch either, even though it is new.
> I just found one the other day ..
> great starter cranking ...but no igntion during cranking.
>
> Scott
> www.turbovans.com
>
>
>
> ----- Original Message ----- From: "Mark" <mbrush@GMAIL.COM>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Sunday, July 18, 2010 5:54 PM
> Subject: stalling and hard restart
>
>
>
> After new fuel tank, pump, filter, lines, ignition switch, temp II switch,
>> a
>> few ground wire clean ups, and an adjusted throttle switch - things are
>> running MUCH better - BUT - I still have a problem. After driving for a
>> bit, the bus will eventually stall and then have a really hard time
>> restarting. Usually happens after I've driven it, get back in and I'm
>> idling to leave a parking lot (STALLS). It's happened often enough that I
>> can tell when it's NOT going to restart. The telltale sign is I don't
>> hear
>> the fuel pump engage for those brief seconds when I turn the key over
>> (before I turn it all the way over). If I don't hear the fuel pump, when
>> I
>> turn it all the way over, it won't start. I keep retrying it until I hear
>> the fuel pump cycle on. Once I hear that, the bus fires up. This
>> happened
>> with the old pump AND the new pump (though the new pump sounds a lot
>> better
>> when it cycles on - the old one seemed to struggle).
>>
>> It happened today, and I tried replacing the fuel pump relay with a spare
>> I
>> have. When I put that relay in, the fuel pump just cycled on continuously
>> (not for the 3 or 4 seconds as normal). It didn't start. I put the old
>> relay in - a few more tries - I heard the fuel pump cycle for a few secs -
>> and it fired up and got me home.
>>
>> I know all the FI parts are interconnected, so it could be a bunch of
>> things
>> (O2 sensor, idle stabilizer, ECU??) - just wondering if this sounds
>> familiar
>> to anyone, or if anything comes to mind.
>>
>> Having fun learning how this machine works - but my machine is telling me
>> that I have A LOT more to learn :-)
>>
>> Mark
>>
>> --
>> Mark
>> 1990 Westy (2.1 - manual)
>>
>
>
--
Mark
1990 Westy (2.1 - manual)
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