Date: Fri, 27 Apr 2007 15:34:04 -0400
Reply-To: Jake Beaulieu <jbeaulie@ND.EDU>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jake Beaulieu <jbeaulie@ND.EDU>
Subject: Re: vanagon Digest - 26 Apr 2007 to 27 Apr 2007 - Special issue
(#2007-436)
>There's really only a couple of ways you can get gas in the oil, and if
>you don't have a dead cylinder (i.e. does not fire at all), there's
>really only one. You have to be dumping gas into the cylinders when the
>engine is not running, and about the only way that can happen is with
>seriously leaky injectors. Pull the injectors and check the spray
>patterns, and look especially for fuel leaking when they shut off.
>There should not be more than a drip or two. My guess is that you'll
>find one or more injectors leaking significantly.
I have pulled the plug wires one at a time while the van is running and
the rpms drop by about the same amount on all cylinders, suggesting that I
don't have a dead cylinder. I have checked all four injectors and the
cold start valve for leaks (several times), there are none. Injectors
were recently reconditioned by Cruzin Performance
(www.cruzinperformance.com) and all have a beautiful spray pattern.
Thermo-time switch is working correctly, thus the cold start valve is only
injecting when it should (i.e. for the first 7 sec while the starter is
engaged).
>Well, according to your earlier description, you're not "at idle" when
>it's first started (i.e. the throttle is open to keep it running). With
>the throttle opened past normal idle position, and the engine RPMs in
>idle range, the vacuum will be very low. You're only going to have high
>vacuum when you generate a high pressure drop across the throttle plate.
Oh, didn't know that.
>>I would like to see the vacuum higher.
>>
>If the idle adjustment (air bypass) is adjusted to allow more air around
>the throttle plate - which is almost certainly the case given how rich
>you're running - you can't get any higher.
hmm...good point. I am running a brand new AFM from Bus Depot and I
haven't touched the initial settings. I also have a working spare. Maybe
I'll screw around with the air bypass screw in the spare and see if it
effects the vacuum.
>>Lifters are set at 0 lash warm,>>>*Really* bad idea IMO.
Well, one could put together a novel from all the lifter adjustment posts
on the list. People seem to have strong opinions on this matter. I
simply defer to Boston Bob, the proffessional who built my motor and has
posted his hydraulic lifter sermon on his website (www.bostonengine.com).
>
>> I set the lifters to 0 lash when hot which is equivalent to 0.006 cold
as I understand it.
>>
>Nope. There's no way to infer that. Zero lash *warm* will equate to
>valves not fully closing when *hot*. Now, I assume that since you're
>talking valve lash, you have solid lifters in you motor. If you have
>hydraulics, you're way off base on adjustment. Hydraulics should be set
>to zero lash (i.e. just touching the pushrod and valve stem surfaces),
>then tightened two turns (or 1 1/2 turns per some folks). Make sure you
>run the motor for several minutes to pump up the lifters, then allow to
>cool for 4-6 hours prior to adjustment.
I didn't realize "lash" was specific to solid lifters. Sorry for the
confusion. I do have hydraulic lifters. I think I will go back in and
set them to 0.006 cold. Again, I defer to Boston Bob's advice for setting
the lifters. Note that the Bentley manual now says that preloading the
lifters is optional.
>First, check your injectors. If you're really getting gas in the oil,
>that's the first problem to tackle and fix. Then adjust the valves
>correctly (Cold for solid lifters) and see where you're at. Hope this
>helps,
My oil reeks like gasoline within a couple hundred miles of an oil
change. I have always thought that gas was washing past the cylinders
while the motor was just barely chugging along while it warmed up. I'll
talk with Bob, adjust the valves, then get back to the list. Thanks for
your advice Keith.