Boost gauge

Last week I installed a boost gauge in my TC. It works well except for one puzzling thing. There is 16 to 18 inches of vacuum at idle but on slight acceleration the vacuum goes up over 20". On all engines I have seen, the vacuum goes down on acceleration. I'm thinking that maybe the cam timing is off a little. I did the "Quick and easy timing belt check" listed on the Dodge Garage web site which says the distributor drive should be parallel to the engine block when the cam lines up with seams in the cam holes and the timing mark on the bell housing is on zero. My cam lines up to the seams and the timing mark on the bell housing is at zero but the distributor drive isn't parallel with the engine block. Am I correct in thinking the cam timing is correct and the Dodge Garage thing is wrong about the distributor drive being horizontal to the block isn't correct.

Last week I installed a boost gauge in my TC. It works well except for one puzzling thing. There is 16 to 18 inches of vacuum at idle but on slight acceleration the vacuum goes up over 20". On all engines I have seen, the vacuum goes down on acceleration. I'm thinking that maybe the cam timing is off a little. I did the "Quick and easy timing belt check" listed on the Dodge Garage web site which says the distributor drive should be parallel to the engine block when the cam lines up with seams in the cam holes and the timing mark on the bell housing is on zero. My cam lines up to the seams and the timing mark on the bell housing is at zero but the distributor drive isn't parallel with the engine block. Am I correct in thinking the cam timing is correct and the Dodge Garage thing is wrong about the distributor drive being horizontal to the block isn't correct.

No, the Dodge Garage is correct. If someone has replaced your timing belt in the past, they likely got the INTERMEDIATE SHAFT SPROCKET indexed incorrectly when setting the 3 sprockets. That does not mean that the camshaft and the crankshaft are not properly aligned. It is just the intermediate shaft that is off a little. This only affects the distributor setting which is likely also not parallel with the engine block when set at the correct initial timing.

From what you write, it appears that the distributor timing could be retarded causing the lower vacuum reading at idle. What you did verify with your checking is that the cam and crank are properly set.

Thank you very much. You have been quite helpful with your knowledge and sharing it with others. Over the last ten years I have owned a 2.5 LeBaron, a 2.2 LeBaron Turbo GTC and now the TC. I had almost no problems with the LeBarons so I'm not as knowledgeable as I should be.