Date: Tue, 13 May 2003 22:18:58 -0700
Reply-To: zampano <matthias.k@ATTBI.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: zampano <matthias.k@ATTBI.COM>
Subject: Re: Vgon syndrome on 1.9 WBX
In-Reply-To: <000801c319d1$7d677fa0$677efea9@ty049008>
Content-Type: text/plain; charset=US-ASCII; format=flowed
ok you guys,
The spark plugs I just changed as well. They were beyond fouled, no
surprise at 8 mpg. There is no fuel leaking anywhere visible. The
possibility of the exhaust being blocked seems ruled out, since I
removed the cat altogether, and the muffler seems fine, as in: I can
blow air thru it if I blow real hard. . Easy now. Seriously, I got the
muzzie to prove it. It's maybe 2 years old as well. I had the
J-exhaust pipe replaced at a shop, and the trip home (80+ miles) went
fine. Although I only got 15 mpg.
I did all the resistance/continuity checks in the Bentley, in the fuel
injection group, they all checked out fine. Even did all the checks
involving the throttle valve/full throttle enrichment valve. Check. My
air filter is rather clean. Fresh spark plugs now. New OXSensor from
ShmAutozone. Resistance is fine on my spark plug / ignition wires. Coil
checks out ok. My injectors spray in nice cone fashion. Checked
resistance on Hall sender, fine. Only things I can think of is the AFM
and the ignition distributor, or maybe the ignition distributor. Have
not checked fuel pressure regulator reliably, but it is maybe 2 years
old, as is fuel pump. Fuel filter is 3 years old. Fuel delivery is
according to spec (Bentley). Timing seemed fine, although maybe a bit
jumpy, to the tune of 1-2 degrees maybe. All vacuum hoses are connected
and tight, heck, they have mostly been replaced when they put my motor
back together under warranty.
Maybe my cold start auxiliary valve is shot, but all the test per
Bentley worked out, though she idles real poorly.
Have not done a compression test yet. Have not been able to really
check AFM, though I did all the checks in the Bentley, and the results
are spot on. (But what is the tolerance when I move the flap, Bentley
and Haynes are rather unspecific...). All my grounds are wired afresh,
and they contact the motor (rebuilt 2 months ago) outstandingly, I
should think. It seems insane that I should be getting 8 mpg.
I bet the farm it's got to be my AFM. It;s been my daily driver for the
last three months, and the bad fuel economy only started 1 month ago
(15-16 mpg city/mixed).
If anybody knows of an accurate way to test the AFM while moving the
flap, let me know, please.
It idles poorly once it's warm, and dies at times, stays around 400-600
rpms when warm, normal (900 rpms) when cold.
I can smell that the exhaust is too rich.
Why am I doing this to myself???
Cheers
m
On Tuesday, May 13, 2003, at 09:30 PM, John McMahon wrote:
> Matthias,
> Has there been a noticeable change in the idle speed, or idle
> smoothness?
> Do the spark plugs appear black, sooty, fouled, wet? Accelerator
> pedal seem
> to be in the same position per mph?
> I am supposing that you've checked the cleanliness of the air filter.
> I am guessing here, but it seems that it has to be enrichment related.
> However, without other symptoms
> showing themselves, that doesn't make complete sense.
> If your calculations are correct, and you are not leaking it
> somewhere, the
> spent fuel has to be going out the tail pipe one way or another.
> An interesting problem. I will be watching for the answer.
> Good luck!
> John McMahon
> Abilene, Texas
>
> ----- Original Message -----
> From: "zampano" <matthias.k@ATTBI.COM>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Tuesday, May 13, 2003 10:07 PM
> Subject: Vgon syndrome on 1.9 WBX
>
>
>> Hi all,
>>
>> So,
>>
>> I checked all the FI sensors and other peripherals. The idle valve,
>> full throttle enrichment
>> switch,
>> checked
>> all the voltages and resistance per Bentley. All checked out good.
>> Checked the ignition timing. Swapped out the ECU, removed the
>> catalytic
>> converter.
>> All didn't make a difference. I just filled her up and calculated I'm
>> getting 8 mpg. This NEVER happened. Seems insane. Maybe she's starting
>> to behave like her possible Detroit replacement.
>>
>> I am going to order a new AFM from Busdepot. Seems like a very good
>> deal actually.
>>
>> It's the only thing I can see being bad, though I can't tell for sure
>> that my AFM is bad. The spec in both Bentley and Haynes don't specify
>> exactly whereabouts the resistance would be if you move the flap. It
>> just says" varying voltage", but no more. As I move it around I get
>> fluctuations between 1100 and 1600 ohms, but it doesn't steadily
>> increase in either one direction. While it idles, the potentiometer
>> arm
>> vibrates, when I open the throttle, it gets steady again.
>>
>> I'll keep you all posted on what happens, hopefully the new AFM will
>> make a difference.
>>
>> Happy Trails
>>
>> matthias
>>
>
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