Date: Mon, 13 Sep 2010 16:10:48 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Fuel mixture too rich?
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reply-type=original
are you sure the idle switch is closing at close to zero throttle ?
I find those not making contact commonly.
if a rare case, make sure that idle signal is getting all the way to the
ecu.
it's a really important input to the ecu.
I 'usually' find that not working right on lots of vanagons.
also the 02 sensor wire to the ecu ..
check if it's shorted or open ..
and watch the voltage swings from the 02 sensor at idle...see if it looks
like it should.
and air leaks/ vacuum leaks ..
cant' say that enough. I have found up to 10 tiny air leaks in a 1.9
waterboxer intake system before.
never hurts to pull the injectors out and watch them spray.
I've tested a dozen before to come up with 4 really nicely spraying ones
that didn't drip.
you gotta have a fuel pressure gauge.
it's rare, but I just found a bad fuel pressure regulator- fuel press was
too high.
aux air reg hardly matters, unless there are air leaks associated with it
and its hoses.
there are no 'cold start components ' per se ..
there's only the ecu holding the injectors open longer when it's cold.
keep digging !
it's in there ...
I see pretty tired 1.9 distributors ...
got the idle stabilizer connected ?
and too advanced timing ..I see that commonly too, and they can't idle
steadily unless they have timing not too advanced, and idle switch is making
contact.
Scott
www.turbovans.com
----- Original Message -----
From: "Barb Ourada" <barbron@EXCEL.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, September 13, 2010 3:03 PM
Subject: Fuel mixture too rich?
> Suggestions needed.
>
>
>
> Have a 85 manual digijet.
>
> Awhile ago, the van seemed to miss or slip power going down the road, and
> since the clutch had a lot of miles, I thought it was due for a change.
> Pulled the engine and did the clutch work. Cleaned the engine while out,
> cleaned grounds, new hoses and clamps, etc., and also new exhaust pipes.
> Put
> engine back in, but did not add cat and muffler before testing. Although
> loud, it started ok, but after a short warm up, it started to hesitate and
> stumble at lower rpm's and load. The first suspects were the cold start
> components not shutting down. The auxiliary air regulator was checked out
> in
> freezer and heated, and it functioned like it should, not real fast
> though.
> The pinch the hose test also was correct. Both temp sensors seemed ok per
> resistance readings. And the idle/full throttle switch was replaced.
>
> The timing has been checked good, the wires are low mileage, and the spark
> plugs are new. I put the cat and muffler on and installed a new O2 sensor
> although the old was probably still ok. Problem still persisted. It seems
> like it is half choking after initial warm up and any load. Going downhill
> and flat after getting into high rpm, it is ok, but lugs on trying to
> accelerate.
>
> The fuel pump is new, and fuel pressure checks ok, and I replaced the
> return
> fuel line to make sure the pressure was not high. Vacuum advance does
> function. Sitting still, and slowly increasing engine speed, it hunts at
> 1500 to 2000 rpm, then revs rapidly after passing that sticky range. From
> a
> parts van, I exchanged the air flow meter, same problem; exchanged the
> ECM,
> same problem. Can't vouch for the soundness of those parts, but I did
> drive
> the parts van home years ago, (no brakes was the problem). So I ordered a
> remanufactured, as they call it, air flow meter, and put it in, with the
> same problem with either ECM in place. Rechecked the coolant senor, and it
> still reads resistance a la chart at the wiring harness. Fresh gas with
> fuel
> injector cleaner along the way did not help. The gas gauge has dropped
> rapidly for the miles, which also leads me to believe the engine is
> choking
> itself. I do live in small hilly area, so the van cannot be driven with
> its
> current attitude. I can't always go downhill, and I am running out of
> ideas,
> and the time spent is getting ridiculous. Also exchanged coils, same same.
> Anyone had a similar problem, and found the fix, I hope!! Thanks for your
> time. Suggestions please.
>
> Ron Ourada, blue 85 wtrbxr.
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