Troubleshooting the VW

Kinja'd!!! "Decay buys too many beaters" (decay)
07/20/2014 at 16:45 • Filed to: None

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Last week my Jetta started misfiring pretty badly, the idle became erratic, and, in general the car was just not happy. I popped the hood and quickly discovered one of the clips that holds on the distributor cap had popped off. I reconnected it and restarted the car and everything was fine again. The next day the same thing started happening, so I popped the hood to find that the same clip had fallen off again. I zip-tied it closed and figured that would be the end of the issue.

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Nope, 10 minutes later same misfiring again. Keep in mind during all of this, there were no codes thrown or check engine lights. So after doing some research I thought the problem might be the maf sensor, but connected a multimeter and found the voltage output to be within spec and I cleaned it just for good measure. I took apart the airbox to look for obstructions and found the hot air valve (the airbox pulls hot air from right above the exhaust manifold and cold air from the wheel well to maintain a constant predictable intake air temperature) was stuck open and constantly pulling super hot air into the intake. I also found and corrected a few small vacuum leaks, checked spark plugs, wires, fuel pressure, and nothing actually eliminated the problem.

In my research I kept coming back to the problem being the maf sensor so I disconnected it completely and surprise! The car runs perfectly, smoother actually than it has in at least a year. So I begrudgingly purchased a new one and tossed it in and now the problem appears to finally be gone.

TL/DR

A 1997 jetta will run perfectly fine with a misaligned distributor cap, superheated intake air, and vacuum leaks. It will barely run at all with a "bad" maf sensor that gives absolutely no signs of being bad.

TL/DR (abridged)

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DISCUSSION (4)


Kinja'd!!! Jake - Has Bad Luck So You Don't Have To > Decay buys too many beaters
07/20/2014 at 16:47

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accurate.


Kinja'd!!! Vicente Esteve > Decay buys too many beaters
07/20/2014 at 16:48

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2 Point Slow owner here! And yes, they are odd engines sometimes.


Kinja'd!!! Decay buys too many beaters > Vicente Esteve
07/20/2014 at 16:52

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On the bright side, after fixing all that, the engine is probably in better shape now than it ever has during my ownership.


Kinja'd!!! Vicente Esteve > Decay buys too many beaters
07/20/2014 at 16:57

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I get the same experience as well, if my car goes to a mechanic, it changes the feel of the engine. Sometimes in good or bad ways...