Hard start

[emerald]

Having a hard starting problem with my 93' ATX. Will start normally if soon after shut down. If let sit for more than a half hour it needs to crank about twice long as normal. Had a mechanic tell me the fuel system could be leaking down pressure. Any other ideas. Thanks. Keith

 

[Bizzy]

Gas cap may need to be replaced if it's not venting properly. (Vapor locked)

Fuel pump could be on it's way south. How does it sound?

You might consider checking into the plugs and wires as well. They make a huge difference in starting.

 

[sdpatt]

That is the characteristic result of the discharge check valve on the fuel pump not holding the fuel line pressure after shutdown. This ball bearing one-way valve is designed to hold the line pressure after the pump shuts down. If the ball leaks, the pressure releases back through the pump into the tank.

The valve is physically a part of the pump and only a pump replacement will correct the problem. This is not a driveability problem and can be avoided during startups by cycling the ignition key a couple of times to ON before turning to START. This allows the pump to run and prime the fuel system before trying to start the engine.

I will at this point recommend installing a higher volume pump when you decide to replace the pump. There is no downside to the use of a 155 or 190 lph fuel pump.