Skip to content
Trust My Mechanic
Trust My Mechanic

Your Free Car Repair Advice and Auto Repair Help

  • Home
  • About Me
  • Contact Me
  • A/C and Heater
  • Auto Repair Questions
  • Battery – Alternator
  • Brakes
  • Check Engine Lights
  • Coolant Leak
  • Exterior Care
  • Front End
  • Head Gasket Repair
  • Auto Insurance
  • Auto Loans
Trust My Mechanic

Your Free Car Repair Advice and Auto Repair Help

Engine Hard To Start When Hot

Austin Davis, March 12, 2013November 18, 2014

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.

Related Posts:

  • How Does The Thermostat in My Car Work?
  • How to Fix a Car That Doesn't Start
  • 5 Common Symptoms of Car Engine Overheating
  • How To Tell If Spark Plugs In Car Have Been Changed?
  • What should you do if your car battery is dead?
Idle & Running Problems car wont startfuel pressure regulator

Post navigation

Previous post
Next post
  • (no title)
  • Front and rear Brake Pads and Rotors
  • How do disc brakes work in cars and light vehicles
  • How do hydraulic brakes in cars and light vehicles work 3D animation
  • Look at How Far my Project Car has Come in a Year
  • 7 Things You Shouldn’t Do In an Automatic Transmission Car
  • How to Change EVERY FLUID in your Car or Truck 
  • 10 Winter Car TIPS & TRICKS you NEED to Know
  • How Much Weight can you REMOVE from your Car?
  • What Happened to the LEMONS BMW?
  • What it Actually Takes to Race a $500 Car for 24 Hours!
  • How to Install Windshield Wiper Brakes
  • How to Replace a Hybrid Battery in a Prius
  • How To Install A Flex Fuel e85 Conversion Kit In Your Car
  • How To Fix A Leaking Rear Axle 
  • How to Install Windshield Wiper Brakes
  • How to Perfectly Maintain Your First Car
  • How To Make Your Car Last A Long Time – Simple Checks
  • 12 Things To Check Before Buying A Used Car
  • Priced for Perfection: The World’s Most Expensive Cars
  • How To Drive A Manual Transmission + Rev Match + Heel Toe Downshift
  • How to Buy a Car To Flip for a Profit 
  • How to Buy a Used Car Interior and Exterior Inspection
  • How to Inspect a Used Car for Purchase

©2025 Trust My Mechanic | WordPress Theme by SuperbThemes