Author Topic: Vanagon horror story  (Read 7058 times)

July 27, 2005, 04:36:59 am

Busdriver

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Vanagon horror story
« on: July 27, 2005, 04:36:59 am »
I installed an AAZ 1.9TD in my 1990 gas powered vanagon. a few short thousand miles ago. Now it won’t start. I think that my major mistake was being hard headed about keeping the air conditioning. I have  manual steering  and didn’t want to convert (back) to power steering so I rigged me up some foolish home made  idler pulley arrangement so that I could have my diesel and air conditioning too.  The turn-key diesel had a serpentine belt that drove the alternator and water pump. It also had an extra v-belt pulley on the crank.
To get the air-conditioning to work, a larger size serpentine belt was used to drive the AC compressor and alternator, while a v-belt is used to drive the water pump and  power steering pump. Not having (or wanting) power steering I rigged up an idler pulley in place of the power steering pump tension the v-belt.  The idler pulley was tensioned with a sliding bracket connected to bolt holes on the (fixed mounted) AC compressor.  

The AC compressor was off Volvo and had the right serpentine belt pulley in the right location and bolted right up to the VW engine bracket.  The home brew idler pulley is the only place I got weird.

Anyway it ran well and kept cool for a thousand miles. Then one of the two bolts holding the  AC compressor to the engine bracket loosened itself and fell off on the road somewhere, and the AC compressor was pulled out of alignment slightly by my idler pulley arrangement.   The serpentine belt got semi-shredded (two out of the original six ribs were still spinning the alternator, and the water pump pulley v-belt was slipping badly.  I noticed all this after I parked it, and  I could not re-start it.

I moved the AC compressor out of the way, installed the smaller serpentine belt which runs the water pump and alternator, and charged the battery, but it still turns over slow and doesn’t start.  So I did my first ever compression test on a diesel.  Whe I had the injectors out, I observed that all four glow plugs were lighting up. The car has been sitting for a few months now, and of course the engine isn’t warmed  up because it doesn’t start, and the starter doesn’t turn it over very fast, so I am not too horrified by the results, all four cylinders were between 410 and 420.  Maybe  the compression would have been higher if it the engine were warm, or if I could get it to turn faster, but it seems to me dragging. The ground cable on the battery gets hot to the touch when I try to start it.

So I look at the fuel.  Dirty, surprisingly disgustingly dirty. And water too! So  I change the fuel filter and prime and bleed and attempt to run it from a 5 gallon can of clean diesel fuel, bypassing the fuel tank entirely. Still won’t start.

What do you think?  Do I have enough compression? Maybe I didn’t get all the air out of the fuel lines, but I am using an electric fuel pump as an assist and the  5 gallon fuel can is above  (uphill, gravity-wise ) of the injection pump.  Should the negative post of the battery be getting hot?
John Koloski

98 Jetta TDI
90 Vanagon 1.9TD AAZ

occasional biodiesel brewer

Reply #1July 28, 2005, 12:51:32 am

fatmobile

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hot post on battery
« Reply #1 on: July 28, 2005, 12:51:32 am »
A hot spot on the battery cables tells me there is a bad connection.
 Fix that and any other hot spots and it might start to spin faster.
 Getting it spinning fast enough can have alot to do with getting it started.
Tornado red, '91 Golf 4 door, with M-TDI 12mm pump, south bend clutch, VNT-15 turbo, 02A trany
MK4s: 2000 TDI jetta, 2003 TDI wagon, 2000 golf 2.0 gasser.
'84 Rabbit with 1.7TD KY block pistons bored to 80mm, VNT-15
'84 GTI with stock 1.6TD starion intercooler.

Reply #2July 28, 2005, 06:59:09 am

Busdriver

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Vanagon horror story
« Reply #2 on: July 28, 2005, 06:59:09 am »
Thanks. I'll look over the wiring and see what i find.  The wiring is 25 years old.
John Koloski

98 Jetta TDI
90 Vanagon 1.9TD AAZ

occasional biodiesel brewer

Reply #3July 28, 2005, 10:49:56 am

fspGTD

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Vanagon horror story
« Reply #3 on: July 28, 2005, 10:49:56 am »
The spec for the minimum cold cranking speed on these motors is 150RPM.  So when you are cranking if you can count the numer of times a cylinder tries to fire in 10 seconds, (this is easy to do with a compression tester hooked up as you just count the "puffs"), multiply that by 12 to determine the cranking RPM.

If you are below cranking speed spec, an effective way to check for current drop is hooking up a multimeter set to measure "volts" to each end of the battery cable.  (Actually, at the starter solenoid, instead of hooking to the 8mm post that the positive cable bolts to, hook to the other one to include measuring voltage drop across the starter solenoid.)  Voltage while cranking the motor should not exceed .5 volt for either measurement.

I found a bad starter solenoid this way.  It was dropping quite a bit more voltage than it was supposed to.  After replacing it with a good used one off another starter motor, the voltage drop became much less, and the engine cranked noticeably more briskly.  This was on a starter motor that was supposedly "rebuilt"!  :roll:
Jake Russell
'81 VW Rabbit GTD Autocrosser 1.6lTD, SCCA FSP Class
Dieselicious Turbocharger Upgrade/Rebuild Kits

Reply #4July 28, 2005, 08:43:50 pm

chrissev

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Vanagon horror story
« Reply #4 on: July 28, 2005, 08:43:50 pm »
Quote from: "Busdriver"
Thanks. I'll look over the wiring and see what i find.  The wiring is 25 years old.


pay particular attention to the negative ground wire that goes somewhere onto the engine or the transmission.   I had the same problem you're having with my 88 jetta and it turned out that the ground wire was rusted so badly that it actually caught fire (yes, there was a flame) and melted at the point where it connected to the transmission.  I had been having problems starting the car before this happened (engine turning really slowly) and I thought I needed a new starter.  I got a new ground wire and found a good place to attach it on the transmission (original place was rusted and melted so could not be used) and the car has been starting perfectly ever since then.
88 Jetta TD....sold for $1000, bought an 06 Cobalt, clearing out the diesel jetta stuff now

Reply #5November 08, 2005, 05:34:23 am

Busdriver

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Vanagon horror story
« Reply #5 on: November 08, 2005, 05:34:23 am »
Well this is weird, but my engine and tranny are stuck together.
The direct ground wasn't helping, the starter just wasn't turning fast enough. The starter and battery are both fairly new. So I removed the starter, half axle shafts, the clutch slave cylinder, the bolts that hold the tranny nose to the chassis. and all four bolts that connect the engine to the bellhousing.  The engine and transmission are stuck, the won't coime apart!  The starter was cranking the motor over slowly, just not fast enough to start. Any ideas on why I can't remove the transaxle?
John Koloski

98 Jetta TDI
90 Vanagon 1.9TD AAZ

occasional biodiesel brewer

Reply #6November 08, 2005, 08:19:54 am

zyewdall

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Vanagon horror story
« Reply #6 on: November 08, 2005, 08:19:54 am »
Quote from: "Busdriver"
Thanks. I'll look over the wiring and see what i find.  The wiring is 25 years old.


Look over the wiring first.  I use stainless steel star washers and anti-corrosion paste on all of my connections now.  I also replaced my main cables with #2AWG or #1/0 welding cable.

If that doesn't help, the symptoms sound like when my truck needed a new starter. Since you said your starter was new, hopefully it's the wires.  On mine, the 4 guage ground wire from the negative battery to the block actually started to melt the insulation off from so much current going through, but the starter was barely turning.  Have you tried measuring the voltage at the actual starter terminals when cranking, compared to the voltage at the battery?  That could give some insight.

I have no ideas on the transaxle, other than more force.  If you can get them a tiny bit separated, see if you can get a prybar in.  Or tap the tranny with a brass hammer or sledge and block of wood to try to knock it loose.  It could be the lineup pins are just sort of siezed or corroded in place.   Just be careful to not bend the tranny input shaft by bending the engine wrt the tranny after it starts coming out.
'84 Mitsubishi 4x4 2.3L turbo biodiesel pickup
'91 VW Rabbit GTI with 1.6 biodiesel transplant
'81 Toyota longbed 2wd 2.2NA biodiesel pickup (for sale)
'89 Subaru 4x4 touring wagon
 '82 subaru 4x4 TDI wagon -- project on hold
1976 Ford Sasquatch pickup

Reply #7November 08, 2005, 01:51:00 pm

myke_w

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Vanagon horror story
« Reply #7 on: November 08, 2005, 01:51:00 pm »
I'll bump your topic cause I like your title, but to me any story about a vanagon is a horror story :]
Contact me for hard to find for idi and tdi parts