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Vanagon mis-fire update

Here is an update on the situation with our 81 air-cooled Vanagon that was mis-firing and running rich since I posted the question last week?.

Swapped out the cylinder heat temp sensor. At the same time took a look at the injectors, and not only did they look pretty dirty, but the little rubber tube connecting them to the fuel ring was cracked and corroded looking so I decided to change out injectors as well. Finally changed the fuel filter and put in new plugs just for good measure.

Started her up and she ran like a charm for about 10 minutes. Then could hear a real faint clang-type (mis-fire?) sound starting and it got louder over the next couple of minutes. Same symptoms as last time. Probably if I pulled the plugs (which I didn't do because I was too frustrated with the whole mess) they would be all sooty again. I pulled off the connector on the cold start valve to see if that would make a difference but it didn't. She just kept running rougher and clanging louder until I just put her (and me) out of miery and shut her down.

Next I figured that I would check for leaks in the cold start valve following the procedure outlined in Bentley.

Beyond that I'm running out of ideas. Does this sound like a timing issue? Air flow meter? Any further insights?

Thanks. marc

Reply to
Bumbletown
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What measurements does your fuel pressure gauge show when it is running well and when it starts to go "bad"??

Speedy Jim

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Reply to
Speedy Jim

Now that you have disconnected the cold start valve, you should clean the plugs and try again.

-- the Grokdoc Tom Malmevik all that groks is god

67 Baja "marti"
Reply to
Thomas Malmevik

I don't recall the mention of a clanging type sound in your original posting. That has me perplexed. Check that fuel pressure. Oh- take a closer look at the distributor. Make sure the rotating breaker plate is attached as it should be and that it is working smoothly. Keep a timing light hooked up and check timing when its running good and when it goes bad. If you have an inductive-type timing light (loop-clamp fits over #1 cable) try it on each cable individually when it runs rough to see if spark on all 4. Assume that if the short hoses at the injectors were coming apart that the outlet and inlet hoses at the tank are bad as well as the ones at the pump. Is there a good flow of exhaust? Has your exhaust pipe been damaged? Did you ever check that oxygen sensor? It takes a few minutes to warm up... Has it ever been changed? It does influence the mixture on that model year if my Bosch book is correct (Bentley Bosch FI book.)

-BaH

Reply to
Busahaulic

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