QuestionI have a 1990 vanagon and it recently stsrting acting up. The vehicle stalled and thena short toime later started. After turning it off it would not start again. Seems that after it gets warm it will stall and then not start until it has cooled off and still starts hard. Any suggestions?
AnswerHi Mark;
I have to be honest with you, and tell you that Vanagon's are not my forte', but I do have a couple of ideas. First of all, the starter issue sounds like "heat soak." The exhaust system exits the cylinders, and eventually the vehicle, but not before going past the starter motor. In any vehicle that has this design there is always a danger of 'heat soaking' the starter with the exhaust heat, and combined with the summer heat, and the hot asphalt surfaces we drive on in the summer the heat in the coils of the starter motor itself increase it's resistance to electrical current flow, and make it impossible to start...when hot. Once it cools off, under the car, it starts.
The runability issue could be related in a round about fashion. Carburetor fuel delivery systems were more susceptible to it but fuel injection systems from the late 70's, and through the 80's had occasional instances of what is called "vacuum lock," or "vapor lock." The fuel in the fuel line that comes from the fuel filter is at a fairly low pressure(compared to todays 65 to 80 psi systems). Since the fuel has just passed through the fuel filter, and become slightly agitated, and perhaps even a little aerated, it begins to turn from a liquid into a vapor at that point, which is at least 2 components too early. It hasn't yet passed through the injector nozzle for atomization, and it hasn't passed around the intake valve for combustion.
The MOST effective way to handle the fuel issue is to install a "cool can" into the fuel path, but it is inconvenient as hell to keep full of ice, or dry ice, and furthermore after the ice, or dry ice melts you are back to the same place you were without the "cool can." Additionally, the fuel economy of your vehicle will be affected negatively, but you WILL have more power. Drag racers use them every run. They are available at many, many local car parts stores, and they are fairly cheap since they are plentiful, and this is racing season, so they should even be on sale someplace close by. The trick is to make the cool can as simple to service as possible. And, it has to be placed between the filter, and the injectors so that even if the conditions outside warrant fuel aeration in the filter, and threaten a vapor lock condition, the cool can will reliquify all of the fuel that passes through it, and you won't stall. On those horizontally opposed engines however, placement might be a real trick, if you know what I mean.
I know that would cure your problem, but it may be just enough to relocate the fuel line from the filter to the engine in a different, more shielded, and hopefully cooler location. If the fuel line runs anywhere near the exhaust system, even within 6 to 8 inches, move it further away. I would even try to insulate the fuel line like insulted windows. Put a larger hose around the fuel hose, and give it some "dead air space" between the 2 hoses, and that will keep it cooler. Unfortunately the injection pump on your vehicle doesn't run at a very high pressure...nominal pressure is 15 to 18 psi, and that is within 10 psi of every carburetor still on the road, so heat can lead to early vaporization, and a "lock."
I hope this helps you clear up your problems with your Vanagon, Mark. If my ideas aren't to your liking, maybe something I said here will jog some thought you have toyed with in the past. Good luck.
