This is a 1997 351w motor and i was wondering if someone knew what this was without taking a pic of it,if you stand in front of the truck it would be on the left side of the coil,and it has a few electrical wires and two vacum lines going into it.it also has a round cap at the top and it turns but not sure if it comes off, but what is it and what does it do.Thanks

 

If it's in front of the coil, is the EGR vacuum regulator (EVR) if, on the left side, its either the TAB/TAD solenoids that control air for the air injection system. But I'm pretty sure you are talking about the EVR

 

Bingo!


For reference: Fuel Injection Technical Library » EGR Vacuum Regulator (EVR)

Another shot here:

 

Yep its the evr ,now do u guys know if its bad would it cause the throttle to surge,and thanks a bunch for the picture of it and letting me know what it was

 

Check the EGR valve to make sure it opens and closes. Ay idle, apply vacuum to the port, the truck should stall, or just about. If that checks out, then check to see if the vac line has vacuum at idle. If it does, its probably bad, if not the valve may be stuck partially open

 

X2...what he said

 

ok i will give that a try nothing else is working,and thanks again guys

 

Have you pulled the codes from the truck yet? That would be what I'd do first..