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Topic: Cold Starting  (Read 2020 times)

Offline Javabirds

  • Dayton, TN
  • Joined: Aug 2009
  • Posts: 101

Cold Starting

« on: October 18, 2009, 02:30:52 PM »
Ahh, my first real day of Bus ownership!  After spending a few hours cleaning her up Saturday, I hopped in Sweet Pea to head to town for a jug of milk.  Brr... Brr... Brr...  Hmmmm.  Okay, I had the doors open and light on for a while so maybe the battery was low.  After a failed jumpstart, I decided to pull the battery and have it tested.  While removing the battery, I noticed that the ground wire was completely corroded and that the positive wire was pretty seriously corroded where it mated with the terminal.  At Auto Zone, I found out that the battery was good but needed charging.  So they charged it and I bought a length of ground wire, terminals and some battery cleaner and battery protector spray.  After wire brushing, cleaning and reassembling the cables/connectors, she fired right up.  Hurray!  Victory dance!  Total cost $16 and a trip to Auto Zone.  I partied all evening!  This morning I went out to start her...  Brr...Brr...Brrrrr...  Well, you get the idea.  It was 37degrees up here on Dayton Mountain this morning, so I didn't try very long.  When  I tried it after a few hours (now about 50 degrees) it fired right up.  So now, at long last, for my questions:

What is the best way to start a Bus?  Clutch/Neutral/Both?  Gas/no gas?  Wait for the fuel pump or not?  Is there a cold start procedure?  What could keep it from starting cold?  What weight oil should I use?  The dipstick has no words, only two lines 1/2" apart about 2" up the stick -should the level be between those lines?  What is the science behind the cold start?  Any suggestions how to test the various cold start components?

Pardon the verbiage, I spent all my $$$ on the van and haven't bought any shop manuals yet!  (I am interested in which manuals you guys recommend)

Offline Russ

Cold Starting

« Reply #1 on: October 18, 2009, 05:36:19 PM »
There is really no special starting procedure. Like most fuel injected vehicles, you don't have to give it gas when you turn the key, it should fire right up. You don't have to push the clutch in either, though I usually do just out of habit from other cars. The fuel pump kicks on as soon as you turn the key to start, and fuel pressure builds up within a few seconds.

There's a cold start injector right on the intake (sometimes called the "fifth injector"). Underneath that is the thermo-time switch. When the engine is cold, the thermo-time switch grounds the cold start injector, allowing it to squirt more fuel into the intake and help with cold starts. After 10 seconds, it cuts off.

You've also got a head temperature sensor near cylinder number three. It's one of the main parameters the FI brain uses, so if it's not working properly you could have starting problems too.

Additionally, there's also an aux air regulator on the side of the intake body. Its job is to open up when it's cold and let more air in, bypassing the main intake. You should basically just be able to remove the hose and when it's cold, blow through it easily.

Before messing with the fuel injection though, go through your ignition system and make sure all the connections are clean and tight. Check the cap, rotor, plug wires, coil, etc. It wouldn't hurt to double check the timing as well as point gap and dwell (unless it's got an electronic ignition). Since you've found corrosion already there might be more. All of the FI components need a good 12 volts to function correctly.

As long as your oil level is between those two marks, you've got enough oil. However, the closer to the top mark the better if you've got hydraulic lifters (which you should).

First book you should buy is the Bentley, it has a nice chapter on fuel injection.

Offline Gobusgo

  • Club Member
  • In a bar in downtown Hell
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  • Posts: 1449
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Cold Starting

« Reply #2 on: October 20, 2009, 07:41:50 AM »
Russ already hit on the thing I was going to mention here...the cold start injector. I had never replaced it on Sweetpea, but put a used one on Oscar when I was having the same issues. The slow starting on cold mornings cleared up. I do have some used ones you are welcome to try.

I also have the owner's manual and the Westfalia's owner's manual for ya. And the history of oil changes and repairs done by me.

A great site for technical answers is Ratwell.com

Offline certdubtech

  • In the Garage...
  • Joined: May 2006
  • Posts: 3199

Cold Starting

« Reply #3 on: October 20, 2009, 08:55:33 AM »
Dang, Travis.  Everybody should have the pleasure of buying an air-cooled vw from you.   8)

I had to sort the titles out on the last two... manuals, paperwork on repairs my butt....  :roll:

Offline Javabirds

  • Dayton, TN
  • Joined: Aug 2009
  • Posts: 101

Cold Starting

« Reply #4 on: October 27, 2009, 09:38:49 PM »
Thanks for advice.  Other than the ground wire and the battery connects I haven't replaced anything.  Instead you taught me how to start my bus.  Turn the key, hear the fuel pump building pressure and then after a few moments turn it over without gassing it.  So far I haven't had any cold starting problems.  I found the manual online and it suggests turning the heater fan off while starting when it is really cold.  Anyway, Sweet Pea has been starting and running great.

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