Hard start

[mason110]

Hello,

 

Im having problems on my 1999 silverado, It will not start right up I have to crank it for a long period or cycle the key on off a few times to let the fuel pump circulate. I replaced plugs, had the injectors cleaned, cleaned intake and fuel system, checked fuel pressure regulator which is good. no ses codes except for EVAP system malfunction, but I cannot find a leak antwhere visible. What do oyu suggest? Thank you in advance.

 

 

By the way its a 4.8 1500 series two wheel drive.

[GM-Tech]

Put a fuel gauge on it and see what happens to the pressure when you shut the truck off. It should hold. If it drops like a rock, the check valve in the fuel pump is probably the culprit and you'll need a new pump.

 

When the pump allows pressure to fall immediately, the line will drain back to the tank. Then when you go to start it next time, the pump has to fill the line before it can build pressure sufficient to start the engine.