I have a vacuum leak where the upper intake manifold seals around the fuel injection control module. The o-ring that goes around the control module is not seating in the upper intake manifold becaue the control module does not go up into the intake manifold enough to seat. The control module is loose at the point that it is attached to the lower intake manifold, I don't know if this is normal or not but it seems like the control module should be about a 1/4 inch taller in order to seal right. Any suggestion?
vacuum leak at fuel injection control module on 1997 Chevrolet 2500 Pickup
by homebuilder in Eufaula, OK on November 14, 2009
ANSWER by backyard tech on November 14, 2009
I've been doing this a long time and have never heard of this. You need to have a smoke test done on the intake system to pinpoint the leak.
ANSWER by Bad68 on November 15, 2009
If you mean where the injector harness plugs in to the injector pack yes this will cause a major vaccum leak. Pull the upper half off again and check that the injectors are positioned in their bracket properly. Not necessarily pushed all the way down. Nothing should be loose. Take it back apart. Good luck.