I have a wonderful 1978 Bus, but it has started running rich and this has caused other problems, most notably clogging the spark plugs with soot, stalling in idle, and trouble starting when the engine is already warm. Has anyone experienced a similar problem, and can you help me with the best way to trace the source of the problem?
Thanks.
I would check all hoses for a vaccuum leak. The fuel injection does not behave well when air gets in where it is not supposed to. Also check temperature sensor. Computer may think engine is cold all the time.
Chris
78 type 2
I have determined that there is a problem with my fuel system, but I have a mechanical testing question. Since I think the problem is with the Control Unit for the AFC Fuel Injection System, is there a way to test the unit? Or do I have to go through and test every other part of the fuel system and rule them out as the problem?
Thanks for any advice you can give me.
Very, very rare for the ECU to "go bad", especially since the engine does run.
Measure fuel pressure to begin with. Check cold start and other injectors for leakage. As already suggested, check the #3 cyl head temp sensor; it has a huge effect on mixture.
Speedy Jim
I appreciate the feedback. The two reasons why I think this has something to do with the ECU: (1) I was reading recently about how jump-starting this particular model could burn out the ECU (and the engine had previously been jump-started a couple of times), and (2) though the fuel is running rich, the engine will stall at idle after it has warmed up.
I should definitely have been more specific about both sides of the problem earlier. I am just getting started in being mechanically inclined and I am using lots of input to help me learn about trouble-shooting my beloved vehicle. If you have further advice or feedback please feel free to jump in with additional thoughts.
Thanks.
Even jump starting should have no effect on the robust ECU (unless polarity was wrong or excessive voltage used). And when they fail it will usually be total. If you can find one with the identical ECU, swap 'em out; otherwise it's ~$300 - 500 to experiment with a new one.
Do the tests we outl> I appreciate the feedback. The two reasons why I think this has
Thanks. I don't have the Bentley manual. I have a Haynes repair manual, the VW shop manual (yes, I know it's hard to get), and John Muir's "Keep Your VW Alive...". I've been reading each of those, and will be checking what you recommend along with some of the additional tests recommended in the books.
I appreciate your patience with a newbie (even one who has always driven a VW).
Doug
Doesn't it have an air flow box? If so check that for flap freedom and electrical resistance of it's sensor as the flap moves. Check the cyl. head temp sensor too!
I might have a Bentley Type II that I don't think I will ever use. I am not sure it covers yours though!
Just some suggestions! later, dave
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