89 jetta starts hard sometimes

[jettavirgin]

its seems to happen when i let the car sit for more than a hour. ill turn the key and hear the fuel pump hum for a couple seconds then ill go to start it and it will crank for 5-6 seconds before starting. it runs fine and if i shut if off while its still warm it will start right back up no problem. any suggestions

[Doug Tatham]

Check your fuel pressure on the injector manifold.
If it's low, I'd try cleaning both the fuel supply pump and the fuel pump. Set them in a dish of fuel injector cleaner or toluene or some other solvent and rotate them by hand. If you use a 12 volt source to rotate them don't make sparks!!! It could be that one of the pumps is getting weak and it's taking a while to bring up the pressure. There is a check valve on the main fuel pump. Make sure it's working right. The check valve is a very likely solution.

You may also want to try running some injector cleaner through your system to remove any gum that may be stopping things up.

The first step to just about any fuel issue is to check the pressure. Monitor it when you start the engine. It should go up to 40 psi right away.

[jettavirgin]

I tried all above to no avail but I looked more into this problem and found gas in the main intake hose on a stubborn start situation. I pulled one of the vacuum hoses off the gas pressure regulator to find gas inside it. im guessing this is the problem so im gonna replace it and see where that puts me.

[Doug Tatham]

It sounds like you nailed it. Replacing the regulator will probably fix the problem.