

| Subject: | Re: strange cut off problem with wbx vanagon update |
| From: | Daniel L. Katz |
| Date: | Wed, 2 Feb 2005 14:40:01 -0500 |
list: an update on my pollution control valve fix. seemed to work well at first, but, evidently, at high rpm, blow-by was sufficient to close down valve, and this in turn caused pressure to rise in crankcase, thus in turn causing oil level to rise in dip stick tube, leaking out all over the place. flapper valve in properly functioning black tower must simply open wider and wider to some maximum with increasing blow-by. pollution control valve in conventional application is different: minimum flow at extreme manifold vacuum, as in throttle almost closed at high rpm going downhill, is shut tight in opposite direction if front fire to prevent explosion inside engine, but allows maximum flow in between, at part throttle, i.e., at moderate manifold vacuum. in short, rather than opening farther and farther with blow-by, the suggested pcv in series with black tower opens farther to a point, then shuts down as blow-by increases still further, thus not properly venting vapors to air intake. therefore, pcv really doesn't mimick action of flapper valve in properly functioning black tower. next try will be a restriction in hose - enough restriction to permit nice idle, but not so much as to create excessive crankcase pressure = and no pcv. i wonder if failed black tower flapper valves have resulted in any engine explosions due to front fires. dan On Sun, 5 Dec 2004 00:23:21 -0500, Daniel L. Katz <katzd54@YAHOO.COM> wrote: >chris: > >our '84 1.9 l had similar symptoms . evidently, the black breather tower >was running wide open, and too much air/blow-by was flowing into the air >intake at idle (too lean mixture i suppose). a quick and dirty way to test >this is to: > >1. pull beather hose off air intake and let hose vent into engine >compartment. > >2. seal up now open intake inlet - duct tape works, rubber cap would be >better. > >3. go for a drive and see if problem goes away, or at least is less severe. > >i inserted a conventional PC valve into breather hose, reattached the >breather hose to the air intake, and reset idle speed (with idle >stabilizer bypassed) to solve the problem once and for all. $2.44 for PC >valve vs $50 -$60 for new breather tower. > >hope this helps. > >dan > > > > > >On Sat, 4 Dec 2004 12:03:06 EST, JordanVw@AOL.COM wrote: > >>ive been having this strange intermittant problem with my '84 van for some >>time now.. >>i'll be driving along fine, then all the sudden if i dont have my foot on >the >>gas, the van will stall out.. no rough idle, no other warning..it will >just >>shut off.. i swapped the ECU and fuel pump relays (little identical grey >>relays in that black box) with eachother and that didnt do anything.. i >>replaced a corroded ground strap from the head to the coil and that didnt >help >>either.. >> >>no strange idle or warning lights precede these intermittant shutdowns.. >>anyone have any ideas? >> >>thanks >>chris
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