Isuzu tech. phone number?

Is there a phone number to call Isuzu about techical problems?


I keep getting a code for "EGR system failure", but the EGR valve is new and I'm getting good flow thru the tube. There is no sensor on the the EGR valve, so how does the ecm know the EGR system has failed.:banghead: I have a 93, 3.2L with a man. trans.

For vacuum actuated EGR valves, you will have a transducer that measures flow and a postioner that sets the vac supply to the dome. It sounds one or both is not working. The transducer measures the differential pressure across the exhaust feed to the EGR base. They are often called DPFE sensors. Trace around the feed pipe for pressure taps to locate the DPFE. The vac supply to the EGR valve dome may also be inop. Trace the vac line from the EGR vlv dome to where it originates to an electro-pneumatic positioner. That positioner might be shot as well.

G/luck
Joel

There are no sensors anywhere that I can find. Could Isuzu be using the MAP sensor to measure the differences in pressure? The only thing I see is a vacuum switch/valve that makes the EGR valve work and it works. I can see the stem on the EGR valve go up and down when I give it gas.