By March 12, 2013 Read More →

Engine Hard To Start When Hot

car is hard to start when hotHello again this is Donald and I was wondering if you could possibly help me out with this question. I have been getting poor gas mileage lately. When the car starts in the morning it starts fine but when you warm it up and shut it off and leave it sit for about an hour and then go to start it again it wont start and stay running unless you push the accelerator to the floor to let the engine breathe.

I think it is getting to much gas and when it does start you can smell gas so today I took the vacuum line off of the fuel pressure regulator and smelled it and it smells like gas and I don’t think it is supposed to so I was wondering if maybe the fuel pressure regulator was going bad in it what do you think and can you please tell me if it is hard to change.

Can anyone do it and if I need any special tools to go with it I have been getting about 22 mpg and should get like 29 hwy mpg right. Please email me back as soon as possible when you get this message.

Thanks Donald


Hey there Donald,

I think I would have your throttle body and idle speed control motor cleaned first and see what that does. If those items are dirty, they will cause rough idle, dying at idle, and slow/extended start complaints.

Also worn out spark plugs, spark plug wires, a weak fuel pump and a dirty fuel filter could also cause your complaint, but I don’t think you have a fuel pressure regulator problem from what you mentioned.

BUT no you really should not smell or see any raw fuel inside the regulator when you remove the vacuum hose. But, then again I would expect a hard start when cold too if the regulator was really bad.

I would however want to use a manual fuel pressure gauge and test the fuel pressure at the back of the engine. An electric fuel pump located in the fuel tank will usually fail when it gets hot, and basically overheats and shuts down.

Allowing the pump to cool off, will restart the engine again until it again overheats and shuts down. Since the pump can be tricky to catch in the act, start with the throttle body clean first and rule that out, it’s easy and cheap to do.

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Austin Davis, consumer car repair advocate. "Hi there! I love to help people solve their car repair problems and I hope my site was helpful to you today. Thank you for stopping by."

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