Date: Sun, 20 Feb 2011 21:57:40 -0600
Reply-To: John Rodgers <inua@CHARTER.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <inua@CHARTER.NET>
Subject: Re: On the road and need some help
In-Reply-To: <4D61D126.9020903@ucsb.edu>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Continuing to drive it like that is definitely not the thing to do. If
you have a cylinder not firing and burning all the fuel, the unburned
fuel will wash down the oil on cylinder walls and the result will be
cylinder barrel damage, ring damage, ring land damage on the pistons and
damage to the piston itself (ring land damage being part of it) Not a
good thing. You could wind up with a very expensive repair.
Let the engine cool, then pull the plug, put your finger over the plug
hole and turn the engine over. You should feel a push if there is
compression. This is not a definitive compression test by any means, but
it will give you some ideas as to whether you actually have ANY
compression. If you have a failed ring or hole in a piston, you will
have no compression. If you do have compression, you likely have an
injector problem. You can check that in the field fairly easy as well,
but it is just a bit more involved - you have to get at the injector
cluster remove it from the head. A single bolt holds it in place. One
removed, you can turn on the ignition and check the spray pattern.
It's a little late now - but you need to add to your road repair kit an
induction type strobe timing light. With this you can clip it around an
ignition wire and it will fire the strobe each time the plug fires. You
can watch the plug action by the way the strobe fires. A regular steady
flash is a good sign. No flash or an erratic flash would indicate a bad
wire most likely - all other things being equal.
Good luck.
John
John Rodgers
Clayartist and Moldmaker
88'GL VW Bus Driver
Chelsea, AL
Http://www.moldhaus.com
On 2/20/2011 8:42 PM, John Goubeaux wrote:
> Thanks all for the suggestions on trbl shooting my "hobbled vanagon" .
> I believe I have narrowed down the problem to #4 cylinder not firing (
> or getting fuel). I pulled each plug wire while it was running and when
> doing so with #4 hardly noticed any change. The plug wire seems OK and
> when compared to #4 has the same resistance when checked with an ohm
> meter. So I am thinking that either the cylinder has lost compression or
> could it be a wonky injector? ( I've already replaced the plugs
> remember) Can a cylinder just loose all compression at once ?
>
> I guess one question I have: Is it harmful to drive it in this
> condition ? Once up to speed on the hwy it seems to move along OK ( and
> coolant temp is normal) but when climbing or under a load it looses
> power. I have about 250 miles to get back home.
>
> Oh yeh BTW I am in HalfMoon Bay about 50 miles North of Santa Cruz and
> am gonna stop by and see Peter at VanCafe so In case parts are needed I
> should be OK.
>
> -john
>
>
> On 2/19/2011 6:48 PM, Mike S wrote:
>> At 07:12 PM 2/19/2011, John Goubeaux wrote...
>>> I'm on the road and several hundred miles from home ( southern CA) and
>>> my 90 Vanagon has begun to run bad. It is missing and has a serious
>>> reduction of power when under load.
>>
>> Try to narrow it down.
>>
>> Remove one plug wire at a time (both ends). If it's a spark problem,
>> you won't notice much difference when you hit the bad cylinder. If all
>> 4 make it worse, then try fuel. Pull the connector from one injector
>> at a time - same thing, if you pull one and little change, that's the
>> bad one.
>>
>> If that doesn't ID a bad cylinder, then the problem is probably
>> systemic - bad timing, coil, cap, rotor, computer, fuel pressure,
>> sensor, etc.
>
>
| 
