Mystery Part Identification (link to pictures!) - likely fuel problem, won't start.

May 02, 2004 7 Replies

OK, experts: I have a 1985 Jetta, 190k miles, CIS fuel system, and the Bentley book (what a wonderful resource). The car does not start. I strongly suspect the fuel system, and not only that, I suspect the problem is between the fuel distributor and the engine (I have successfully performed all the check tests for fuses, pumps, and pump relays). When I loosen one of the injector hoses from the distributor, I get no gas leaking out (but when I loosen the hose into the distributor from the fuel pump, I get pressurized gas spray). Sparks are A-OK. I have no clue how its compression is, but the car starts when you spray ether into the air intake.



While I would love your help in this matter, here's the real reason I'm writing. When I crank the motor to start it, an awful buzzing noise comes from under the hood, from the fuel distributor area. I have an awful suspicion that this noise is coming from the mystery component shown here:

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What is this part? It's got an electrical harness connector attached! Believe you me, I scoured the Bentley, and there is NO mention of this part anywhere. I am perplexed. Got any ideas? If it's buzzing, and you know what it is, does it follow that my car won't start?


-vinny


don't remember what it is called, but i know it always buzzes... or atleast mine does (my cars run) and i was told it was supposed to buzz... although one of them is louder than the others...

have you tried jumping the fuel pump relay? That's usually the first to go... there are two big prongs on the relay... jump those two slots on the relay panel and see if it runs then...

good luck... i dont know what else to tell you... never had a problem with the fuel distributor... just 4 fuel pump relays and one fuel pump...

Does the car keep running after you've sprayed ether into the intake? Any loud buzzing from the rear passenger side of the car which would suggest a bad (in-tank) transfer pump?

Darryl.

It's called the frequency valve for the Lambda(O2) control and it should buzz. In a nut shell it controls the fuel/air mixture by changing the duty cycle of the valve. This make the engine go rich or lean depending what the signal is from the O2 sensor. Some years it also made the engine run rich for after a cold start.

The part is the frequency valve. It varies the fuel pressure depending on O2 sensor output.

To get fuel out of the distributor you have to raise the airflow meter plate that's under the boot.

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