RE: My 1990 Testarossa Since both of my Fuel Pressure Regulators starting leaking 'abruptly' They needed replace, which required the removal of the upper intakes. No issue there (other than the previous owner not knowing the difference between Hex and Torx and hammering it in apparently on the bolts), but there are some 'nipples' on the fronts with small (1/4"?) hoses drawing vacuum from these on the fronts, and I of course forgot to mark them when removing. I looked in the service manuals and couldn't find them, and the nipples (one 90 degree, one straight) are marked as non-US but I have a US car.... Can anyone explain what these hoses are for; and does it matter which is which (I would say the bore on the angled one is larger so presume it does)... I can track down the destinations but that won't help me. Any advice/info source would be appreciated.
For the front of the left 7-12 plenum, vacuum sources are for WSM page D2 electronic ignition, and WSM page H6 AC vacuum reservoir.
Left - as in Passenger US? And, does it matter which hose goes to which nipple? It may be that one of them crosses over to the same nipple on the other side? I will check the manual if I can find it, UPDATE: Yep, I see the references but unclear as to which nipple feeds which hose... MAYBE I see that the inboard on (closest to the center of the engine) is the AC one, but very unclear.
Richard, 7-12 is 7-12, and is on the left driver side US. My past notes say AC control vacuum hose connected to left plenum inside port, and the ignition control vacuum hose connected to the left plenum outside port. I had marked same, but I do not think it really matters. Steve will probably jump in if he does not like this. No crossover, my 86' right plenum has only one nipple for the SMOG control located under the right side fender. EDoug
Thanks, that is what I thought but I will say that the angled one looks like it has a larger 'bore' so maybe has more vacuum. And the pictures seems to support this. But I do have nipple(s) on the passenger side; the driver side is where I messed up. I will check and see where is all goes and make it this way. The car runs ok I think (haven't road tested yet) but it seems there is a 'roar' that wasn't there before, all of the hoses and connectors are tight as are the gaskets on the intake... we shall see ... Much appreciated for the quick response. PS I agree the passenger side might only have one nipple, the other port is plugged.
Only to add that the single vacuum hose on the 1-6 bank plenum also runs the differential pressure valve system (which functions like the accelerator pump of a carb during cold-running to squirt enrichment during throttle blips) so that function needs to be maintained even if the smog (air injection system) is disabled.
Thanks, it will be a good idea for me to check both that I have the correct hoses in the correct place AND that the other ends go where they are suppose to, as well. I was careful but worth checking all of this
