ISC is good. Clogged IC or IC pipes?

[emd645e3]

I was checking the vacuum lines for leaks and what not, and they all checked out fine. I noticed that when I took off the line to the brake booster, and didnt plug the inlet up with my finger, the idle smoothed out completely. I came to the conclusion that the surge (about 1250-1500 RPM 2 times a second) has to be caused by lack of air, not too much air. It makes sense to me, but does it make sense to anyone else? Maybe there's some kind of restriction in the intake or IC pipes, or the intercooler itself? I know the previous owner had a 14b on the car that took a dump, and maybe he didnt clean out the oil that got into the system?

 

[95blackGsTurbo]

Very good possibility. Take the IC out and soak it in gas for a while to get all of the oil out. Flush it out real good to make sure nothing is left inside and clean the IC pipes really good. Did you try replacing the line to the brake booster to see if that might be pinched or clogged?

 

[emd645e3]

I'll be cleaning the IC out tomorrow. I'll test the booster line and see what happenes, also.

 

[emd645e3]

Is the vacuum line for the brake booster supposed to be able to suck in air, or is it an absolute vacuum?

 

[95blackGsTurbo]

Absolute Vacuum. It shouldn't be pulling in air. If it is, it's got a leak.

 

[emd645e3]

Well, its not pulling air. I thought maybe the booster let some air through it, but I thought wrong.