So I've been experiencing some "fluttering" recently. Once the car warms up it flutters or jerks (slightly) when holding the speed at about 40mph (1700 rpm.)

I removed the hose from the EGR valve and plugged it and that made the fluttering go away when driving it so I figured the problem was probably the EGR valve or ports ... so I purchased a vacuum pressure gauge to test it.

When I hook it up to the valve and apply vacuum, the engine sputters so I figured the valve and ports are working properly.

When I hook the gauge up to the hose (instead of the valve) and increase the rpms to about 2000 or so, the gauge registers vacuum for a split second and then drops to zero. This makes me think my solonoid (located in the control box) is bad.

I'm not very knowledgeable when it comes to mechanics so I'm probably missing something. Any thoughts on this? Any help would be appreciated. Thanks.

UPDATE:

I bought some hose and extended it from the #16 hose into the passenger seat ... hooked up the vacuum gauge and went for a spin. Brought it up to operating temperature and tried holding it steady at about 40mph (1800 rpm.)

There was not a stitch of vacuum. Never registered at all.

I brought it back and let it idle for a few mins and took another spin. This time, as I put it in drive and headed down the long driveway, it registered about 8 inches as I was creeping along around 10mph. Stopped at the end of the driveway and accelerated out onto the road. Vacuum held steady at about 8" ... for about 15-20 seconds then dropped to zero.

I held the speed steady at 40mph but no vacuum registered again. Brought the car back to the driveway and parked it. Revved the engine a couple of times ... no vacuum.

Sooo, there it is ... any thoughts?

I'm going to guess it's either the solonoid or the main computer.