Vacuum System has lost it's suck

Hi Guys,

355 Spider - 5.2 Euro model

Today I removed the the vacuum assembly (tank, solenoids, air pump etc) as I wanted to see if I could fix the air pump that has not operated since I had the car (fuse keeps blowing).

The pump has had it (internally welded) and neither of the solenoids are working so I put everything back.

Having started the car I noticed that I no longer have any vacuum being produced. I disconnected the vacuum source (from the engine) from before the tank and there is nothing.

The vacuum was fine before & I know everything is plumbed in Ok. The worry I have is that I stupidly decided to test the air pump after I had dismantled it and freed the impeller. I only had a 25amp fuse available (instead of 15/20 amp) and this caused the air pump motor to smoke (fuse didn't blow) , so I quickly switch off and removed the fuse.

So have I killed something ?

What would stop the vacuum being generated (is this not mechanically generated)?

Any ideas appreciated and once again thanks for any help you can give.

 

Not sure where the vacuum port is on the engine (where it's eventually connected to the board with the solenoids and vacuum tank) but you need to see if there is vacuum at that point. I would certainly think there would be. That would mean your vacuum hose is plugged/collapsed/pinched somewhere.

The air pump has nothing to do with creating vacuum. Mine is unplugged (electrically) and vacuum for the exhaust bypass valve still works fine.

 

cheers, I have tested the vacuum prior to the connection to the vacuum tank and there is nothing. Before, the vacuum pulled quite strong from this point. I have followed the pipe back to the engine to the point where it disappears into the engine housing and the pipe is fine.

 

Track the vacuum line from the accumulator back to the throttle bodies, and find where it gets connected.

Only below the throttle plates is there any vacuum in these motors.

 

I have pulled the vacuum pipe from both throttle bodies and checked the pipes for leaks and its fine. I reconnected to the ports and noticed that I can blow air into the pipe. Should this be possible?

Does anyone know how these ports are fed, is there any other pipework involved?

If I start the engine and put the vacuum pipe to by tongue there is a tiny amount of suck.

Any ideas?