Engine Mechanical problem
1993 Acura Integra 4 cyl Two Wheel Drive Manual 135000 miles
My stock '93 Acura Integra LS won't start when it has been sitting in very hot weather for a couple of hours. The engine will turn just fine, but it won't actually start. If I wait for a while until the ambient temperature drops, the car will start up like new. I had never heard of vapor lock, but after some research that seems to be the most likely culprit. What can I do to fix this?
The vehicle is equipped with self bleeding and during initial ignition on, the fuel pump will operate for 2 seconds to purge the system. If it is really vapor lock, try turning the ignition on for 2 seconds and off then repeat a few times and see if it starts. If it is vapor lock, it should start.
You might need to look at the fuel pump main relay which tends to have bad soldering points if the above does not work.
May, 25, 2008 AT 5:16 PM
When you say that I should " turn on the ignition", do you mean turn fully to actually start the engine, or just turn the ignition until the power is fully on? Or does it make a difference? I have tried completely turning the ignition repeatedly, but I have not stopped short and just " powered" the ignition repeatedly. I will give that a try (the next time I'm in that situation) and see what happens.
Also, just to make sure I understand, vapor lock would not occur in my vehicle unless the relay isn't working properly? I was also considering new spark plugs, but the engine seems to be getting plenty of voltage, as it turns over just fine.
One last thing I just thought of - it has been idling very low (intermittently), but runs fine when accelerating. I was thinking that perhaps my fuel pump is going bad. Could that explain why it wouldn't start in hot weather, yet starts fine the rest of the time?
May, 26, 2008 AT 6:29 AM
Switch on only, do not crank as cranking will get the injectors working thus reduction in fuel pressure.
If you can get a fuel pressure test when the vehicle is not working, that would be the best.
One simple way of checking whether there is vapor lock is to unloosen the fuel relief pressure valve and switch on the ignition. If fuel gushes out with high pressure, then is not vapour lock and also not the cause of your hard starting.
However if it there is no pressure or bubbles, then there is vapour lock or the fuel pump is not functioning maybe due to the pump itself or the current supply which is from the main relay.
May, 26, 2008 AT 12:07 PM
Youre problem is you're 'fuel pressure regulator" needs to be replaced.
June, 3, 2008 AT 8:41 AM
You need to replace the main relay. I had the same problem on my 94 integra. The part cost me only $75 and it just plugs in down by the gas pedal.