# Lag in throttle



## Cincy240fan (Dec 31, 2006)

Ok so i have a question about my 95 240sx. It is an automatic and sometimes in the morning or after the car has sat for a while and the engine has gotten cold when i press down on the gas pedal the call will lag and seems like its gonna die, but it never does and then when i give it more gas it picks up with propblem. i was wondering what the propblem might be.


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## Dustin (Dec 14, 2003)

i'd be willing to bet it's a vacuum leak.


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## Cincy240fan (Dec 31, 2006)

i know im gonna sound dumb but what would cause that?


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## rogoman (Dec 16, 2004)

One of the major areas of possible vacuum leaks are the intake plenum connecting bellows; there's one at each end, next to the MAF and next to the throttle body. Check them for cracks. Also inspect the other connecting hoses and clamps.

The sure way to determine the possibility of a vacuum leak is to install a vacuum gauge. To check the intake system for a vacuum leak, attach a vacuum gauge to a full vacuum source. A good place to connect to is the charcoal canister. There should be three hoses connecting the carbon canister. Two of the hoses go to a purge valve that's built into the canister. The second larger hose off the purge valve should be your vacuum line. With the motor fully warmed up, the reading at idle should be 18 - 20 InHg. At 3,000 RPM, it should be 21 InHg.


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