Good Evening Everyone. Well, the car was running great again. By the way, I have an 89 IROC with the 5.7, all stock, rebuilt about 40k ago. Anyway, all is fine and all of the sudden Im going thru town and it starts chuggin or pulsing real hard almost like its out of gas. Before you ask, I checked the gas even though the gauge said half. Not it. Well, I drive it this way back to the house. I go out a couple hours later and it fires right up and runs perfect. Yesterday, the wife tells me as shes sitting on the side of the road that it did it to her two days ago and now it has done it and shut off. Difference is that this time it isnt fixing itself. I lift the hood and notice that even though I have the spark plug wires tied back, they are actually stretching under heat and laying on the manifolds. Maybe a problem, but not this one. I start it tonight with the intent of looking for a bad wire before replacing them and notice a vacuum noise coving from the passenger side between the 2nd and 3rd runner. I cant see anything except a vacuum pod, but Im sure the sound is coming from under the tpi. Can anyone tell me whats under there and the best way to get to it. Ive never had the tpi intake apart. It almost looks like I can just pull the runners off and get to most of it. Is this true. Thanks in advance for any help. Bob

 

Start the car and spray the suspected area with some throttle body cleaner and listen for idle changes. If it does change then you've narrowed down the vacuum leak. You have an EGR valve under there and a fuel pressure regulator along with some vacuum lines for the brake booster and pcv valve and maybe something else that I might've missed.