My local fiero shop would charge almost 300$ to locate and "fix" any vacuum leaks, i feel like itd be smarter to just replace the vacuum lines with rodneys. I read ill need to replace the upper plenum gasket as you have to remove it to get to the lines. Is there anything else in the process that needs to be replaced? Also any personal experience on the difficulty of replacing the vacuum lines? Also ill do the EGR tube
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Hello, I have done a quite a few of these, one using Rodney's and one using The Fiero Stores lines, and others with stock replacements. Both RD's and TFS were good and both required a little bit of tweaking. Nothing major or discouraging though. Be sure to get a 10mm and 8mm 12-point socket for the intake bolts and bolts that holds the throttle body heater lines in place. It is a pretty much easy and straight forward task. The only thing else I would do at the same time if needed is fuel injectors and or pressure regulator, valve cover gaskets if weeping or leaking. Good luck with the project
------------------ "Because in a split second, It's gone" Ayrton Senna
[This message has been edited by Ponnari (edited 05-17-2016).]
The upper plenum gasket probably should be replaced after you've had it off, but if you're careful and do not disturb it, there is a chance you may be able to re-use it. When I replaced my vacuum lines, I replaced my gasket, but then, I replaced almost everything, since it's all thirty years old now. If you re-use the old gasket, make sure you torque the plenum bolts to spec (18 Ft-Lbs) to help the old gasket seal as best it can.
The vacuum lines are dead easy to replace. Because it's vacuum, you don't need any clamps, except in some certain cases (the brake booster line). Also, depending on how you feel about engine bay dressup vs functionality, there's no reason the vacuum lines need- to be solid. You can replace them all with soft line, though they won't last as long as the Rodney's lines. When replacing vacuum lines, just remember to follow the vacuum diagram, and when you've double checked and feel done, check everything a third time.
When replacing the EGR tube, it helps to remove the heat shield between the tube and the Distributor/coil. It gives you a lot more room to work. But be sure to put the heat shield back into place, as the EGR tube does get very hot. In fact if you can sew, you can put the old tube's heat blanket over the fiero store's tube and double up on heat shielding, give your ICM even more of a fighting chance.
When replacing the EGR tube, test your EGR valve's diaphragm as well. With the engine cold, feel under the top of the valve, and you can find the diaphragm. Put your finger over the nipple and push the diaphragm up. If it moves or hisses, you have a bad diaphragm ( and a vacuum leak) and should get a new EGR.
With the vacuum liens and plenum off, also check your PCV valve. Take it off of the hose and shake it; The "valve" is a ball bearing check valve. If it rattles, it should be good. If your PCV doesn't rattle, replace it while you're in there.
You can replace most lines with rubber tube and take more direct routes, it just doesn't look as neat and they kind of get in the way. I do them one at a time and blow through the tube to check that it's the one I think it is. There are other things to check, like the fuel filler, cruise control, emissions canister, valve cover gaskets, oil filler cap, brake servo, anything connected that could let air in. This is why it's expensive to find the leak.
