I have looked through some schematics and the only wires I found were to the solenoid/swithing valve, but nothing to the EGR valve itself. The reason I am asking is because I got a code 53 and I am trying to figure out which of the 4 possible problems it would be. Just a note, I put direct vacuum onto the EGR valve and it did not open. I can move it with my fingers so I know it is bad, but how does the computer know?

Mark

 

It only knows about the solenoid. Not sure exactly what "high voltage at the EGR valve" means, unless it is high resistance or an open circuit that the ECM can see.

When you put the vacuum on the valve, was the engine running? Some valves are a "positive pressure" type, that needs the engine running in order to open when vacuum is applied. Wierd, but true.

 

When I threw the meter at the switching valve it read 14.15 volts at idle. I thought this was kind of high but I don't know.

It is a negative system, at least that is the way I understood the way the numbers read on the valve itself, the last digit being a "N" (supposedly that tells you it's a negative pressure system). I bypassed the switch and ran the vacuum line directly to the poted vacuum port on the base of the carb (the one that goes to the switch anyway, I just took it straight to the valve). And yes, the engine was running at idle and I would take it up to around 1500 with no change. I put the vacuum gage on the same port and at just off idle I got 5" which is what the book (Chilton's) said I should get.

P.S. HEY five7! Some how I knew that I would get first response about this from you!

Mark