[cngr96]

I replaced the intake manafold gaskit on my 99 3.2 ES. Now it is hard to cold start. Requires long cranking times. When engine is warm and is shut down, then restarted ~10 minutes later, it requires long crank time to start and engine runs real rough for 10 seconds then all is well. No codes shown. It acts like there is no fuel in the lines and has to pump it to the engine. Is there a check valve somewhere to prevent fuel from going back to the tank when pump is not running?

I'm open to any ideas.

Thanks, Dan

 

[peva]

There are generally four ways the fuel rail can empty itself while sitting: One or more fuel injectors is leaking fuel into their respective cylinders because their pintles are not shutting off completely (sticking open or tip not closing against the seat due to trash or residue), the upper o-ring of one or more fuel inhectors are leaking fuel onto the engine (you should smell raw fuel before attempting to start if that is happening), or the fuel pressure regulator or check valve (both located in the fuel pump assembly, which is in the fuel tank) are leaking.

If any of those are happening, you can test for that by cycling the ignition switch 3 or 4 times before cranking. Turn the key to RUN and wait for 2 or 3 seconds, return the key to OFF and wait for 2 or 3 seconds, repeat 2 or 3 times, then crank to start. If the engine then starts without pronged cranking, then - yes - something is allowing the fuel rail to empty out. This works because when you turn the key on, the fuel pump is run by the PCM for only a second or so and then stops. Only running one time isn’t enough to re-fill the rail, but running several times is enough to re-fill and pressurize it.

When it does start after cycling the key, it will run rough for a few seconds and then smooth out because of some air still trapped in the rail (and also due to some cylinders being flooded with raw fuel if any injectors are leaking down).

 

[Rider500]

As peva mentioned I'd look at the injectors. I had similar symptoms when I had an injector leaking. When listening to the injectors with a stethoscope, I could hear one that didn't sound the same as the rest. When I pulled the plenum off you could see that same cylinder had discoloration in the intake port from too much fuel. New injector solved that.

 

[peva]

For injector issues (sticking pintles or tips of pintles not completely shutting off against seat) due to residues/deposits, you can try Sea Foam or Techron in a couple of tanks of gas to see if that gets rid off the problem. Quite often that works, but not always. A secondary benefit is that it will remove carbon deposits from the intake ports, valves, and combustion chambers.

 

[cngr96]

For injector issues (sticking pintles or tips of pintles not completely shutting off against seat) due to residues/deposits, you can try Sea Foam or Techron in a couple of tanks of gas to see if that gets rid off the problem. Quite often that works, but not always. A secondary benefit is that it will remove carbon deposits from the intake ports, valves, and combustion chambers.

Thanks rider 500 and peiva for the response. I will try these suggestions and let you know the results.

 

[1wayson]

I replaced the intake manafold gaskit on my 99 3.2 ES. Now it is hard to cold start. Requires long cranking times. When engine is warm and is shut down, then restarted ~10 minutes later, it requires long crank time to start and engine runs real rough for 10 seconds then all is well. No codes shown. It acts like there is no fuel in the lines and has to pump it to the engine. Is there a check valve somewhere to prevent fuel from going back to the tank when pump is not running?

I'm open to any ideas.

Thanks, Dan

have you done a fuel pressure test at the fuel rail?