How do you guys find your vacuum leaks? I recently pulled the upper intake manifold on my s4 to do the omp delete and after putting it all back together my car has the symptoms of a vacuum leak. Ive already blow vapor smoke into several different lines and saw no smoke rise from anywhere. I also tried isopropyl alcohol in a spray bottle and soaked anywhere there could be a leak. And i used the propane torch method. My car does idle at about 700-1000 (Does drop down to 500 sometimes and itll bounce around and almost die) but thats with the mixture screw tuned to as rich as possible which I'm not comfortable with. The fuel pressure regulator is working just fine as is the fuel pump. The air pump is bare, no lines are attached to it and i unplugged all the connectors going to it. I havnt been able to test the tps because all the write ups are for the s5 which is a much different system, but i did unplug it which just made it die. Before i adjusted the mixture screw it would die at idle

Air pump area





Throttle body





Dynamic chamber





Engine bay. Ive rotated the afm back to oem position and its made no difference





dynamic chamber

 

First off, what the hell is sticking out've your thermostat housing???????

Also, did you use all new gaskets? Sometimes getting the upper/lower manifold can be a PITA to seal

How did you block off the OMP injectors?

 

Its some ebay water neck. And i blocked them with the block screws from pineapple racing with thread lock. And i didnt use a new gasket but i couldnt find any leaks around the manifold using any of the methods i named

 

what is that under the TPS connector?..big hole looking thing that looks like a hose connection?

 

Air pump intake. Ive had it disconnected forever

 

I read many threads where people have reused the intake gaskets, and couldn't find a vacuum leak, but it was their problem. new gaskets are alway the way to go when your in there, they are over 25 years old, and they are cheap, don't be cheap with these cars, they will bite you back when you try and bite a penny

 

Yeah youre probably right. Ima take the manifold off again and put in new injector seals and do the gasket

 

Since your gonna be that far, may as well take the lower off and replace that gasket as well and free up your 5th 6th ports if your still using them