Stop and go Buick

My son’s 2000 Buick Regal 6-cylinder sedan has an intermittent habit of not starting. At first we thought it was because his fuel gauge wasn’t working because he would add gas from a gas can and it would start. This is definitely NOT the problem. It is very erratic, and when it does this, it usually starts later when he tries it again, but there seems to be no rhyme or reason to when it starts or doesn’t start. Whether the engine is warm or cold, how much gas is in the tank, the weather, etc., nothing seems to make it more or less likely for this to happen, except of course that it does it at the most inconvenient times and in the most inconvenient places. Once it does start it runs fine. We’ve changed the fuel filter, and it seemed to us that if it was a fuel pump problem it would just not start, period. Has anybody run into this problem? Could it be a small leak in the fuel line that’s letting air in, maybe? I’d sure like to be able to take it to my mechanic with an idea of what’s wrong and how much it’s going to cost!

Maybe a bad neutral safety switch. Next time it won’t start try shifting from Park to Neutral. Then try to start the engine in Neutral. If it does start, have the neutral safety switch replaced.

Please tell us a little more about the car and the problem. How many miles, is the check engine light on (is the light working-should be able to see it when you first try to start). When you say does not start, is it no sound when you turn the key, or clicking only, or does the starter spin but not engage the engine, or does the engine crank but not start?

I don’t remember the mileage but I know it’s over 100,000. It cranks just fine, but it doesn’t start up, not even an attempt to bust off. The check engine light is not on. It sounds and acts like it’s not getting any fuel, even when the tank is full. When the problem first started, it seemed as if my son could put gas in the tank from the can he kept in the trunk, and the car would start right up. Now that’s not working and it’s not starting more often.

My son just texted me: the car has 197,000 miles on it.

you really keep a full gas can in the trunk? that is scary. I do keep one in my pickup bed. but it is secure and protected and I can see it and I check it every time I drive to make sure its ok. I will sometimes get gas for my lawn mower in my car, but I put the can in the floor where I can see it and grab it if necessary. and I don t even like that

Since it does crank, the neutral safety switch isn’t the problem. Let your mechanic diagnose it. That’s his job. We’re just guessing here. He’ll be able to tell whether it’s getting spark, fuel pressure, etc, and if there are any stored codes.

Well, the car is on its way to the garage, so I guess that finishes this discussion. I was hoping for a quick and easy answer, but not expecting it - I know it was a lot to ask for! Thanks to everyone who tried to help - I sure appreciate the responses!

" It sounds and acts like it’s not getting any fuel, even when the tank is full."

The standard test is to spray starting fluid into the air intake while cranking. If it starts (and then usually stalls when the spraying stops) it’s definitely not getting fuel. There are also anti-theft devices that can cause intermittent no-start problems.

Try this link. My friend’s car had a similar problem.

Fuel pumps can be very erratic-working sometimes and not others. Listen for the pump running to see if its working or not. If not bang on the tank and see if that jars it loose.

Since the car is being examined by a mechanic who can see and test the car, this thought may well be moot, but…I think that there may be a clue contained in the following words “it seemed as if my son could put gas in the tank from the can he kept in the trunk, and the car would start right up”.

Think about it–if there is a problem in the evaporative emissions system, merely opening the gas cap momentarily (even if gas wasn’t added) may have temporarily resolved the issue, thus allowing fuel delivery to take place.

@Merla–Please report back to us after the mechanic gives you his diagnosis. Even if it turns out that I am wrong, I am interested in hearing details on what the mechanic found.

OK VDC, I’m not firing on all cylinders today but can you expand on how a problem with the evap system could cause a fuel starvation problem?

@Bing–If there is a blockage in the liquid/vapor separator (or in the vent line between the liquid/vapor separator and the carbon canister), the fuel tank won’t be able to “breathe” properly, and fuel starvation can result.
It’s relatively rare for fuel starvation to happen as a result of this situation, but it can happen–and with the huge number of miles on this particular car, I wouldn’t rule it out as a possibility.

If a blocked vent is causing fuel starvation, there should be a hissing sound when you take the gas cap off as air rushes into the tank.

OK thanks VDC. I’m still back in 1965.

Just to expand a bit on VDC’s explanation, what can happen if the tank can’t breath is that a vacuum can form in the tank’s airspace as the fuel is pumped out. The vacuum can become sufficient to prevent the fuel pump from pumping gas.

This can come from a malfunctioning component in the evaporative emissions system or from a fuel saturated charcoal bed, sometimes the result of “topping off” the tank.

Let us know what the mechanic finds. We do care.