Why do I sometimes need starting fluid to get my 94 Jetta to start?

Some history on what I've done to the car so far:

Replaced spark plugs with Bosch 4301's

Replaced exhaust system with aftermarket no-name cat-back

Replaced battery before winter 09


95% of starts are fine. 100% of the time, when the car is started, it runs without issues. I did have a stutter problem when hitting the accelerator off the line, but that was fixed with changing the plugs.

In the few cases where the car doesn't want to start, spraying some starting fluid into the air intake housing allows the car to start without incident.


It's never the same weather conditions when the problem occurs. Sometimes it will be cold, other times warm, sometimes it will rain, other times it's dry. The problem has happened during 3 different seasons so far (fall, winter, spring).

When it happens, it can also go for months without happening again. The engine always turns, I've never had just the starter turning, so I don't think it's the starter.


I'm assuming that it's not the starter because it's such an intermittent problem and the starting fluid fixes the issue.

Also assuming it's not a faulty connection in the ignition coil for the same reason above.

I don't have any acceleration problems once running, so I doubt it's a fuel pump issue.

Could it be the fuel filter?

Maybe the air filter needs to be changed? (but it doesn't look dirty at all)

Should I just change the stock intake altogether? (it is pretty old, after all)


Are the vacuum lines easy to change?

Meaning, are they just buy new ones and replace or do I need to do anything else to prime them before I put them on?

I'm pretty handy, but I'm definitely no car expert :P

3 Answers

  • Briano
    Lv 5
    10 years ago
    Favorite Answer

    Replace the ground cable from the battery to the frame and the frame to the engine.

    Clean your ISV Idle stabilization valve it is between the Valve Cover and the Throttle body.

    Replace the BLUE CTS sensor, it is on the head water outlet flange (do not change it with the car is hot).

    Get thee a Bentley, as they are the bible of automotive repairs on this car.

    The Blue CTS causes numerous issues when flaky, and no start when cold or hot is one.

    Your o2 sensor can cause no enrichment on start if it too is bad.

    But the biggest issues that I have seen on dubs in the 30 some years of watercooling, is the grounds. Replacing the grounds will only assist you in the future.

    Occasionally spraying Ether in the TB is ok, shoot I have never lost a engine doing it,

    but it shouldn't be used on a regular basis, even in Diesels.

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  • Anonymous
    10 years ago

    1. You don't use starter fluid on an engine with spark plugs. (Unless you don't want pistons). Starter fluid is for diesels that don't have glow plugs.

    Gasoline has more bang than starter fluid.

    5. Check your vacuum lines. Pull off the little hoses and squeeze the ends. These are rubber hoses so you should be able to squeeze them closed. If they are rock hard then they are not grasping the metal nipple tightly and air is being sucked past them. (A household vacuum sucks at 7psi--a car is double that(minimum)). The stock intake is fine and can last till the car is 100 years old.

    not starter, not battery, not ignition coil, not muffler, not intake manifold, not smelly pine tree air freshener.

    Source(s): mechanic
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  • 10 years ago

    No intention to offend but you are clearly no mechanic by your diagnosis and conclusions..

    Mail me with more details about the car and I will try and help. 94 Jetta tells me nothing.. Diesel? Auto? Carb? Fuel injection? K-Jetronic? What? A few pics of the engine should make the problem easier to help solve..


    Source(s): 30 years in the trade....
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