thebannister8
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- Oct 25, 2011
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hi there...i'm new here and have an 89 gmc sierra with a 5.7 litre...i went and failed smog today and was checking out the tbi...i have 5 vacuum hoses...4 in the front and 1 in the back...it's all hooked up as it should be according to the diagram on the air filter...i notice though that the far right inlet has zero or near zero vacuum at idle and a little vacuum at higher revs...the other inlet have a significant amount of vacuum...the far right one goes to the egr vacuum solenoid...is that inlet supposed to have very low vacuum...i poked a wire through and it it does go through to inside the throttle body...it seems though that the hole on the inside of the throttle body is very small...thanks