Did you have any other symptoms to confirm the pump was at fault? E.g. pressure drop in the fuel lines after ignition switch turned off?

I keep coming back to what could blow off the duct as an indication that something else is wrong. The fuel injection "spider" under the intake plenum (on which the throttle body sits atop) can leak allowing fuel to accumulate below the throttle body.

 

I didn't check the pressure, I just went ahead and change the pump. It was a cold morning when duct blew off upon starting it, could that be a cause?

 

How cold is cold to you? I've started mine when it was 15'F (and perhaps colder) with no problems.

I'm a big fan of knowing why I am replacing a part before doing the replacement. It is possible that the fuel pump was bad and replacing it helped address the fundamental problem. It is also possible that the fuel pump was fine and it was just a coincidence that the other symptoms seemed to change at the same time. (BTW, these fuel pumps tend to eventually fail so replacing it was at worst a preventative measure.) It is also possible that there is still something else going on.

 

It was about 28 degrees that morning. No, replacing the fuel pump had nothing to do with the current issue. The duct blew off the morning I was getting ready to change the fuel pump, before I changed the fuel pump.

 

In your original post you said you could hear air being sucked in somewhere, is that still the case? That you had this pop off, apparently with enough force for the wingnut to be lost to me sounds like something bad going on. I'm running out of suggestions besides taking off the duct between the throttle body and the air filter and doing a thorough visual check of it and everything else on the intake plenum. Also grab the throttle body and try to move it to ensure it is all secure.

 

My bets he broke the nut, the air plenum didn't blow off it vibrated off, And the sound may just be the clutch fan noise as its running

 

 

And how is your problem? Did you manage to fix it?


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