I did a head swap on my 85 Iroc. It is the TPI. I put some fully ported 75 305 heads on it that a friend let me have. Problem is it is now running like crap. It bogs(I did the timing a million times)finally I got rid of the bogging a bit there still. After a while the car will act like it is over heating and all I hear are the lifters or something. So I checked them and they are fine. Today it left me stranded for about 20 minutes then it fired up. I do have a few exhaust leaks due to headers warping. Could that throw my ECM off? I hooked all my vaccum hoses up again but I may have missed something. Anyone have the hose diagram for the TPI? I wanna doble check it maybe I missed something. Or if anyone can think of something better please give me insight. It is overheating now it seems since it killed on me and didn't wanna start until it was somewhat cool. Man this is making my day. I know I should
ve left well enough alone but the speed bug bit once again and I had to have these heads since they were practically free. Help me out TPI gods. Laters
Paul

 

I have a hose on the vavle cover on the passenger side that was connected but now is not. I have many friends with the TPI engines, one with an orignal 85 and non of them have it. It looks like a PCV hose or maybe an evacuation tube? It spits oil somewhat but not much. Thing is I can't remember where it hooks up too. I know that was stupid.
Anyone???

 

That hose is a vacuum source. Its the pcv valve hose. Look for a barb fitting somewhere at or near the rear of the plenum to connect it to.

 

That hose on the pass side is the breather. It goes from the valve cover to the throttle body. Comes up from the valve cover in a 90* grommet, has a 2.5" piece of metal tube that points towards the plenum, a 90* elbow, a 12" longe tube going forward and an S shaped hose from there to the throttle body.

 

So that Passenger side tube connects to the TB then? Could that be a reason for a loss of pressure? My friend just called me to tell me that he found a tube on the garage floor where we worked on it. It used to come up from below the ALT and connect to the TB. The one right above the coolant line of the TB.

 

Well see if this solves this little problem. I can't stand it

 

That's the one! you're going to need that.

 

ThirdGen, I just sent you a couple of pictures that might help, so check your email.... If I was at home I could take a picture of the routing diagram and email it to you.....

 

Thank you I just gothome and read them. Could that line be causing this much headaches? If you also send me a close up of the FPR hose that would be great. Thank you everyone. This is why i love this site. Great people in here.

 

Yes! you are getting unmeasured air in behind the MAF and this will wreak havoc with the computer.

 

So the bogging(Obvious air problems and timing) and the wanting to kill on me symtoms are because of that damn tube. That sucks. Well its not all the problems but one of the main ones. Thank you.