ok not the pipe below the egr
valve! but i do not know how to test if the computer is sending anything, and my local AutoZone says they cannot scan the computer this car is too old, local body shop told me not to bother with the egr
system? he said that the car is running and looked at the egr
valve and system and said it is working properly, don't worry and put a piece of tape over cel
? this is going to be a SHOW car, so it must be perfect!
Well one way to test the EGR
& VSV to see if the VSV is getting a computer voltage command to open, is to fully warm the engine, open the throttle & let it snap closed, while watching to see if the EGR
valve pintle moves.
If it doesnt move, disconnect the vacuum line between the EGR
valve diaphragm & the VSV Output port to the EGR
valve, where ever it's easiest to access.
Then with the engine fully warmed up, connect your vacuum gauge to the Output VSV port, or disconnected EGR
diaphragm vacuum line, or put your finger over the port or the disconnected vacuum line at the EGR
diaphragm & open the throttle to rev the engine & when you let the throttle snap closed, you should measure or feel vacuum at the VSV Output port, or disconnected vacuum line to the EGR
valve diaphragm, if the VSV is working & recieving an electrical signal from the computer to open & apply vacuum to the EGR
If you Don't feel vacuum on the VSV Output port, or vacuum line to the EGR
diaphragm when the throttle snaps closed, then suspect the new VSV, or that it isn't getting an electrical signal from the computer to open & apply vacuum to the EGR
valve, OR, maybe the vacuum line between the intake manafold & Input side of the VSV has a problem.
If you come to suspect the computer isn't sending an electrical signal to the VSV to open, back probe the VSV electrical connector to see if the signal is there. If not there, then back up to the computer firewall electrical connector & back probe there. If you don't have a pinout of the computer firewall connector, look for the same color code/stripe wire thats on the VSV electrical connector. If no signal at the firewall connector, suspect the computer VSV driver has gone belly up.
Again, if all that checks out, look/inspect to make sure that the small feedback differential pressure port/aperature, inside & below the EGR
valve, is clear of carbon deposits. If its clogged up, it'll not be able to apply EGR
feedback & that'll corrupt the PFE/DPFE sensor feedback pressure measurement across the feedback aperature/port, that the PFE/DPFE sensor measures & the electrical signal it generates & sends to the computer will be corrupt, so the computer will get confused about what to tell the VSV to do, to control the EGR
valve, all a really vicious circle.