I cleaned my engine this weekend with foamy engine brite and now I have a vacume leak. I have a single turbo so none of my searching helped it just came up with troubleshooting for twins. What spots should I check. It seems to be a pretty substantial leak because it would go down to 20 vacume when shifting and now it only goes to 10 or less. No racing, no excessive revs or speeding. I just cleaned the motor and now even at idle the vacume is less. HELP ME OUT PLEASE!!!

 

Whilst it seems hard to imagine you could have a mechanical failure from simply washing the engine bay, check if some of the lines have filled with fluid & are blocking the vacum signal.

I traced out a vacum leak on my 92 & in the process noticed some fluid inside the lines along the way. Although the problem ended up being something else (the joys of twin turbo's) perhaps you induced some into your lines

 

Your symptoms are indicative of a disconnected MAP sensor as well; you might want to check that first.

Then, check all the obvious entry points into the FD manifold... hmm, off the top of my head, there are:

- 2 nipples on the UIM, usually capped from the factory (the popular boost gauge tap point)
- 1 nipple on the LIM, towards the firewall (above rear rotor), on the inside (facing the block), usually connected to the FPR
- 1 big port on the UIM that connects to the brake booster crossover hard-line via a rubber hose
- 1 big port on the UIM on the front side of the t/b that connects to the PCV system
- three small nipples on the front side of the t/b that connect to various turbo stuff (vacuum res, etc)
- two or three small nipples on the back of the t/b, one of which should attach to the map sensor line

I don't think I missed anything... only due to the fact that recent troubleshooting on my car requires that I remove the UIM in its entirety approximately three (3) times daily.

That failing, verify that your idle air control valve, and or AWS solenoid are not stuck open. The idle air bypass valve is the valve on the back of the UIM with the white plug; the AWS solenoid is directly under the UIM. Both should close if you disconnect them.

 

Check every line coming off of the manifold. That's where the subsystems get their vacuum.

Dave