Hi,
I need some advice on a car start issue. My 2007 Camry doesn’t start when it is warm but starts normally when it cools down. For example, if I drove to the grocery store, shut off the engine, waited 1 minute and tried to start it again, it will start and stops immediately but if I left it to cool down for 10-15 minutes it will start normally again. I have been to couple of mechanics, they changed the cam and crank shaft sensors, ignition coils. The last advice I got today is to replace the fuel pump, the mechanic inspected the pump pressure and he said it is higher than normal. I really don’t want to pay another $600 for fuel pump and then it turns out again that it doesn’t solve the problem. I really appreciate your advice as I am really tired of visiting mechanics and spending money.
Thanks!
When it doesn’t start warm, you need to test whether it’s lacking fuel or lacking spark. Get a can of starting fluid (“ether”) and if it cranks but does not start, spray a couple seconds worth in the air intake, then try starting again. If it starts briefly, that means it lacked fuel. If there’s no difference, that means no spark.
Thanks Shanonia, The mechanic did that today and it was starting and almost stopping but as he sprays more it maintained the engine running until it became steady. Do you think it is the fuel pump then. He said that it might be the fuel pump but he is not sure and if we replaced it there will be no refund if it doesn’t resolve it.
That sounds like a case of vapor lock
Vapor lock occurs when the vehicle is driven, and when the engine is shut off hot, the engine heat starts to boil the fuel in the fuel rails. then if you wait long enough, the engine cools down to a point where the engine will start.The fuel system is suppost to prevent that from happening by holding what’s called residual fuel pressure over a certain time.
So,have your mechanic perform a residual fuel pressure test to see if that’s what’s happening.
Tester
An easy way to test that is to, once it doesn’t start, turn the key on till all the lights light up (KOEO) for about 6 seconds, then turn the key off (KO) for 6 seconds, then KOEO for 6 seconds, then KO for 6 seconds, due that about 6 times and then see if it starts right up… If it does then you are loosing residual pressure… Basically you are primming the fuel pump doing what I described, you can also do it with the fuel pressure gauge hooked up, but not required…
Why?
The fuel pump only runs for a second or two and shuts off.
Why?
You’re just letting the fuel run back into the fuel tank if there’s a problem with the anti drain-back valve
Tester
That is how you prime a fuel pump…
Edit: that is an old school test to see if it is loosing residual pressure
No it’s not.
ON-OFF-ON-OFF-ON-OFF…
Each about 2 seconds.
Tester
OK, I’m not going to argue with you over something I have been doing for 30 years now…
Me?
Over 50.
Tester
You do realize we are saying the same thing except for the 2 or 5 seconds thing…
It;s called the key dance
And that’s the way every mechanic I know does it since fuel injection arrived.
Tester
AGAIN, You do realize we are saying the same thing right???
I said about 6 seconds, about also means around, close to… lol
Thank you all for sharing your advice. I have a question about a case of vapor lock, if that turns out to be the case, is there a way to fix that? if yes, how expensive is it usually?
How long have you owned it? Miles?
When doing the key dance, less time with the key at Off means less time for fuel and/or pressure to bleed off before another try at Start.
Where can this fuel and/or pressure be going? Back to the tank through a leaking anti-drainback valve? Somewhere in the EVAP system, due to a different valve problem? Both those scenarios would mean lack of fuel and/or pressure at the engine.
If it were through a leaking injector, wouldn’t the car still start pretty quickly with maybe a stumble, and then run OK (unless the injector was open all the time)?
2 month now, the mileage is 107k miles.
It sounds like you have already done a lot of troubleshooting and have had a few mechanics take a look at your car. It is understandable that you don’t want to spend more money on a fuel pump if it may not solve the issue.
I would suggest that you take a look at the fuel pressure regulator. It is possible that the fuel pressure is too high and the regulator is not able to keep it at the correct level. This could be causing the engine to shut off when it is warm. You can check the fuel pressure with a fuel pressure gauge. If the pressure is too high, then you may need to replace the fuel pressure regulator.
Another possibility is that the fuel filter is clogged. This could be causing the engine to shut off when it is warm. You can check the fuel filter by removing it and inspecting it for any debris or blockages. If the filter is clogged, then you will need to replace it.
Finally, it is possible that the spark plugs are worn out or the spark plug wires are damaged. This could be causing the engine to shut off when it is warm. You can check the spark plugs and spark plug wires by removing them and inspecting them for any signs of wear or damage. If the spark plugs or spark plug wires are worn out or damaged, then you will need to replace them.
I hope this helps and good luck with your car!
I guess I would also have a look at the engine temp sensor that establishes the fuel ratio at a given engine temp. My old 68 dart woul do this due to the choke. Same concept.
Thanks for the detailed information! I tried this, the car started and stopped again. Does that mean that it is not a vapor lock and I should replaced the fuel pump, regulator and filter?