vapor lock?

[gmoneyjive]

Been having this problem for a while now... every once in a while (2-3 weeks), I go to start my car, and it turns over and then stalls. So I try to start again, and it won't start, it seems to be suffering from fuel starvation. It won't start again unless I let it sit for a few minutes, then it starts fine - other than this it runs perfectly fine (other than the fact it's an old shitty '92 civic).

I know vapor lock used to be a problem on older carbureted cars, but I've heard that it can also affect fuel injected engines as well (which mine is). I also thought it might be a fuel pump problem, but I've had those before in another car and it usually affects it at higher speed (high fuel flow), so I don't think that's it.

A few things perplex me tho - first of all, this only happens once every few weeks, and it doesn't seem to happen when I'd think the engine would be at it's hottest - say, after an hour at high speed on the highway. It seems to happen after a short trip when the engine is only stopped for a minute or 2. Also, I've heard vapor lock can cause some power loss or worse not even reacting to the throttle at all, and this simply isn't the case. Once the car is running, it is fine... the trouble only seems to be in starting it.

I know there's some pretty knowledgeable people on here... am I way off the mark on this? Or what else might it be? And if it is vapor lock, what can I do about it? A few suggestions I've found so far are to check the cooling system, and to make sure fuel lines aren't near anything that gets too hot...

btw... this also happened a bit with my old '90 civic (tho not as bad)... I wonder if it's a civic thing lol

one more thing... I made the mistake of trying to pump teh accelerator one time, then it wouldn't start for hours, I guess this is a bad thing, right?

[bigpoppanils]

if its vapor lock, i doubt your car would be starting at all

[teklord310]

hmm...

Try the distributor cap and rotor... its a cheap option.

Try some injector cleaner.

Lets see what the other guys have to say.

Here is something i found online:

Could this be a classic case of vapor lock? Very possibly. Vapor lock used to be a common affliction with carbureted engines during summertime heat. Engine and exhaust heat would raise temperatures under the hood and near the fuel line until the fuel literally boiled. As the fuel boiled in the fuel line, the fuel pump could no longer pump it. If the engine was running at the time -- not at all uncommon -- the symptom was a complete loss of power. In many cases the engine continued to idle, but would not react to opening the throttle at all. If the engine vapor locked after shutting it down hot, the symptoms were precisely as you've described -- it will crank over but not fire. Can vapor lock occur with modern fuel-injected engines? Absolutely.

Reflecting on the basics -- an engine needs air, fuel and ignition to run -- your best course of action is to check for fuel and spark while cranking the engine in the "no-start" condition. An old spark plug or timing light can be used to check for spark. With the key off, adding a small amount of fuel or volatile aerosol through the throttle body or a vacuum line, then cranking the engine, should tell if it is a fuel starvation problem.

If the engine starts and runs for a couple of seconds on the fuel you added, it's either vapor lock or some continuing issue with the fuel pump, fuel pump relay or computer system.

If you determine it is a loss of fuel pressure, try carrying a large squirt bottle of water in the car so that when this scenario occurs you can spray individual fuel system components under the hood such as the fuel rail, pressure regulator, throttle body, etc., to rapidly cool them off, then try restarting the engine. If you find you can get the engine running again by cooling, for example, the fuel rail, then you've identified vapor lock as the problem.

The only solution is to lower underhood operating temperatures by servicing the cooling system and cleaning debris from in front of the radiator and A/C condenser, and trying a different source of fuel. You might find a fuel with a slightly lower vapor pressure that will reduce the potential for vapor lock.

So it doesn't sound like vapor lock.

[gmoneyjive]

Originally posted by teklord310

hmm...

Try the distributor cap and rotor... its a cheap option.

Try some injector cleaner.

Lets see what the other guys have to say.

Here is something i found online:

Could this be a classic case of vapor lock? Very possibly. Vapor lock used to be a common affliction with carbureted engines during summertime heat. Engine and exhaust heat would raise temperatures under the hood and near the fuel line until the fuel literally boiled. As the fuel boiled in the fuel line, the fuel pump could no longer pump it. If the engine was running at the time -- not at all uncommon -- the symptom was a complete loss of power. In many cases the engine continued to idle, but would not react to opening the throttle at all. If the engine vapor locked after shutting it down hot, the symptoms were precisely as you've described -- it will crank over but not fire. Can vapor lock occur with modern fuel-injected engines? Absolutely.

Reflecting on the basics -- an engine needs air, fuel and ignition to run -- your best course of action is to check for fuel and spark while cranking the engine in the "no-start" condition. An old spark plug or timing light can be used to check for spark. With the key off, adding a small amount of fuel or volatile aerosol through the throttle body or a vacuum line, then cranking the engine, should tell if it is a fuel starvation problem.

If the engine starts and runs for a couple of seconds on the fuel you added, it's either vapor lock or some continuing issue with the fuel pump, fuel pump relay or computer system.

If you determine it is a loss of fuel pressure, try carrying a large squirt bottle of water in the car so that when this scenario occurs you can spray individual fuel system components under the hood such as the fuel rail, pressure regulator, throttle body, etc., to rapidly cool them off, then try restarting the engine. If you find you can get the engine running again by cooling, for example, the fuel rail, then you've identified vapor lock as the problem.

The only solution is to lower underhood operating temperatures by servicing the cooling system and cleaning debris from in front of the radiator and A/C condenser, and trying a different source of fuel. You might find a fuel with a slightly lower vapor pressure that will reduce the potential for vapor lock.

So it doesn't sound like vapor lock.

yeah... I found the same site, and that's the reason I thought it might be a minor form of vapor lock that only happens on occasion. I've had a distributor go before, and it was nothing like this, I had majority loss of power, and pretty much couldn't drive the car. Cleaning the injectors might do the trick tho - I'll give it a shot.

[cintron]

how about changing the fuel filter? that's usually a biggie.