Date: Thu, 13 Dec 2001 00:46:02 -0800
Reply-To: Bess's Buddies <bess@EARTHNOW.ORG>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Bess's Buddies <bess@EARTHNOW.ORG>
Subject: Re: 87 Lack of power
Content-Type: text/plain; charset="us-ascii"
Thanks for your help!
We changed the air filter... and boy was it nasty. Worst airfilter I had
ever seen. We also changed the fuel filter, and it too looked like it was
original (172k on Bess now)
It didn't fix the problem. <sigh>
We disconnected the O2 sensor, and it drove just the same. No power over
3200 rpm. Fine torque in first, fine running in low rpm range. Starts and
idles nicely, rev's up fine when idling.
Excuse me for being such a newbie to fuel injection and computers and such
(our volkswagens have always been 40hp's)....
1. What is an AFM? I see in the bentley the whole system is called an
"AFC". Is it the "intake air sensor" (Air Fuel Mixture?) attached to the
air cleaner?
2. This "TempII" sensor, is it the one the bentley just calls "Temperature
Sensor" that on the left hand side of the engine behind the spark plug?
How does one test that temp sensor... with the engine running to see the
range in readings with the coolant temp? Or just a couple static readings
cold, warm, etc.?
I'm a little nervous soldering that digitool to our computer (Is that the
"ECU"? The bentley calls it a "Control Unit") ... is it scary? I'm a bit of
a computer geek so I do know how to run a soldering gun, but soooo many
connections!
So we can floor it, and it doesn't rev up... but there is no gas going to
the cylinders as we had pulled a plug and it's running nice and beige. My
gut instinct tells me it's "intake air sensor" by the aircleaner...? is
that the AFM?
Another issue that might play in this, but I doubt it.....as Bess had ran
fine then. The idle stabilizer was acting strange and it wouldn't rev down.
(Oh, the days when it would rev up!) the wiring that goes to the "Idle
stabilizer control unit" was fried way back into the harness that went to
the power steering pump switch. It has now been disconnected, and has been
for awhile. It just is rough until it warms up, but the whole rev problem
went away.
But could it be related even though there was time in between (say 1000
miles or so) that Bess ran well?
Thanks for helping me identify these items.. then we'll test em!
Bess's Buddies
Glen & Rianda
At 06:44 PM 12/2/2001 -0800, you wrote:
>Hi,
>
>Hey that sounds just like the problem I just experienced in my 89
>Syncro Westy. I just got it out of the shop yesterday and my
>mechanic though it may be a clogged fuel filter so he changed that.
>When was the last time yours was replaced?
>
>That seems to have resolved my problem for now but I need to drive it
>a while to see if it comes back. My symptoms were occuring once the
>engine was warmed up (so it seems) and at that point I had no power
>over 2500 RPM and could only go about 30mph. Someone on the list
>suggested a clogged catalytic converter, faulty ground connections to
>the cylinder head, faulty Oxygen (O2) sensor faulty TempII sensor and
>lastly faulty AFM.
>
>The O2 is easy to diagnose. Just remove the green wire from the O2
>sensor. (below the coil) and see if the problem persists. If it goes
>away you have it easy - Replace the O2 sensor that is your culprit.
>
>If the O2 sensor is OK and assuming everything is in OK working
>order, the TempII sensor is the other targeted culprit. If it does
>not send the right signal to the ECU and AFM, the AFM goes into idle
>mode. So no power.
>
>The AFM may also be defective so you may have to test that out as
>well. Follow the steps in the Bentley repair book.
>
>I would not mess with any timing and distributor setting until all
>the electronic sensors are fully diagnosed. Assume your timing and
>sparks are OK. Do you have a DigiTool? or are you good at
>electronics? there is a fellow on the list that has created a tool
>to diagnose all the sensors going to the ECU - the DIGIFANT. Darrell
>Bohler has the diagram available on his web site. Check it out at
>http://www.loam.org/vw/Vanagon
>Darrell also posted all sorts of mechanics training manuals called
>the ProTraining manuals that get into diagnosis of each sensor and
>system.
>
>
>Good luck,
>
>Joel
>89 Syncro Westy MV
>Rochester NY.
>
>--- Bess's Buddies <bess@EARTHNOW.ORG> wrote:
>> Hi all,
>>
>> Our 87 has a strange problem... she has fine low end torque, and
>> when not
>> under load will rev up just dandy, but when she is under load, she
>> won't go
>> over 3300 rpms no matter what, and has no power over 2000 rpm.
>>
>> We haven't done a compression check yet, but are planning to. Funny
>> though,
>> she runs well and purrs otherwise.
>>
>> Is this a "normal" problem that may be easy to diagnose via the
>> list? She
>> kinda feels like she has a bad advance on the distributor? Is that
>> possible
>> in a new car?
>>
>> Thanks oh wise list!
>
>
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