My 78 Westy is back on the road in Illinois

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locoqueso
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Location: Grayslake, IL 60030
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My 78 Westy is back on the road in Illinois

Post by locoqueso » Fri Jun 12, 2015 7:21 am

Tuesday June 9th of 2015 is the day I believe we finally identified the cause of the hesitation/bucking/stalling problem that has plagued my 78 FI bus for years. I have enough evidence now to blame the Temp Sensor II for most of my stress and headaches. Here’s my first post about the problem back on July 27th 2008:

viewtopic.php?f=3&t=4605

Colin was onsite for his 2015 visit this week. We spent the first part of the day fine tuning and troubleshooting why this bus was running so poorly. The fuel in the tank was stale and we found the fuel filter was jammed with crud. Unfortunately a tune-up, fresh fuel, and a new filter did not eliminate the symptoms. I was getting a little worried that it was going to be a very late night. That is until Colin picked up the Temp Sensor II wire connector during a vacuum test and instantly noticed an improvement. I had a spare sensor in my collection of parts so we installed it and then readjusted the AFM.

I was prepared for some type of disappointment however it never occurred. During our first test drive the bus ran better than it has in years! It’s not like we haven’t looked at the Temp Sensor II before. Colin even tested it himself this year and confirmed it was within spec. I also tested it several times in 2012. It was the first time I’ve ever tested a component so I made this post looking for some advice:

viewtopic.php?f=42&t=10601

After Colin’s visit this year and replacing the Temp Sensor II, I completed a 100 mile test drive and it was smooth driving the entire time. I should say that I’ve only been able to drive my bus 20 miles in 2 years. I barely made it around the block and back to the garage the last time I tried it in November 2013. After 100 miles I’m very optimistic that replacing the Temp Sensor II has resolved the problem.

It’s hard to believe that I’ve been chasing this gremlin for almost 7 years. I was starting to accept the possibility that my bus would always choke and stall on the road. I’m going to nominate Randy in Maine for an award because he was the first to call out the sensor as a possible culprit in his reply to my original 2008 post. I’ll also nominate Colin for his help this year to confirm. I'm so glad to be back on the road again. My bus and I thank you!!!

Here's the full list of our work on 6/9/2015:
  • Valve adjustment
  • Cleaned valve covers
  • Replaced points
  • Adjusted timing
  • Drained old fuel
  • Replaced fuel filter
  • Checked fuel pressure
  • Adjusted AFM
  • Checked vacuum
  • Replaced Temp Sensor II
  • Fixed horn
  • Replaced hub cap
My goal for 2016 IAC Visit:
  • Resolve heavy oil leak (main seal?)
1978 VW Campmobile (P-21) Westfalia - T2 2.0L F.I.- 151,000m
1982 Mercedes-Benz Estate Wagon (300TD-T) - S123 3.0L T.D. - 142,000m
1993 Dodge Maxi Van (190 SLF) InterVec Falcon - B350 Magnum 5.9L F.I. - 70,000m

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Amskeptic
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Re: My 78 Westy is back on the road in Illinois

Post by Amskeptic » Fri Jun 12, 2015 9:20 am

locoqueso wrote:Tuesday June 9th of 2015 is the day I believe we finally identified the cause of the hesitation/bucking/stalling problem that has plagued my 78 FI bus for years.
Image


Such a horrid little sensor. We checked that thing over the years. It met/meets specifications! It does/did TOO. BUT, the little #@*!&@!*^! had a devious little internal open/short/demonic possession that ONLY presented itself because I accidentally!! pulled on the wire while my vacuum gauge was attached to the manifold vacuum line, and the needle on the gauge steadied out? WTF?

Now, I do believe that the clogged fuel filter (see diagram 1) ....
DIAGRAM 1 Clogged Fuel Filter

Image


.... gave us that dodgy trip to the gas station where we had to motor along at an idle, and motor home at an idle where I was shifting into 2nd at 8 mph and 3rd at 18 mph. Hilarious, huh?

Second test drive was a relief (see diagram 2)
DIAGRAM 2 Relief

Image

Enjoy that car. Drive it. Bond with it.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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locoqueso
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Location: Grayslake, IL 60030
Contact:
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Re: My 78 Westy is back on the road in Illinois

Post by locoqueso » Fri Jun 12, 2015 10:57 am

Amskeptic wrote:...Second test drive was a relief (see diagram 2)
DIAGRAM 2 Relief

Image

Enjoy that car. Drive it. Bond with it.
Colin
I can't remember the last time I smiled while standing so close to that bus. It was a good feeling. This will be my summer to drive. There's a VW club show next weekend and it's only about 165 miles away in Montecello Indiana. I think that may be my next trip.
1978 VW Campmobile (P-21) Westfalia - T2 2.0L F.I.- 151,000m
1982 Mercedes-Benz Estate Wagon (300TD-T) - S123 3.0L T.D. - 142,000m
1993 Dodge Maxi Van (190 SLF) InterVec Falcon - B350 Magnum 5.9L F.I. - 70,000m

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