anybody ever seen anything like this

[kansasvmax94]

i just replaced my opti spark on my 94 formula. I have ram air. I noticed a small diameter hose connected to the rubber boot in front of the mass air-flow sensor which was connected to the bottom of the old opti. it looks like whoever installed this, which appears to be somesort of vacuum or breather hose, just hogged a hole out of the bottom of the opti and pushed the hose into it.

Any idea why this was done. The hose was completely blocked with crud in the opti side, i guess just crud from inside the opti. OH, also, should my old opti rattle like it has broken pieces inside? (just a joke)

[kansasvmax94]

oh, bye the way, my new opti from Dal Slabaugh, doesn't have the reamed out looking hole in the bottom, but is identical in every other way i can see, i should hog out a hole in the bottom of my new opti should i??????

[94 formula]

Looks to me like whoever had it before you did that just as a vent system like you said. And no I would just leave it how it is and install it don't hog out the hole.

[pete]

Your pictures came over dark, so there is no detail to your opti.

The previous owner was probably trying to update the hose setup to what the 96-97 used. It takes two vacum hoses.

If you look at your new opti, the base plate has 3 small holes on what would be the bottom when installed. If you plug two of the holes (I used small pop rivets, or use some small screws) and drill out one to 3/16" and insert a 3/16" 90 deg. plastic vacum hose fitting, then run a 3/16" vacum hose up to the rubber air intake hose ahead of the MAF. The latter opti's cap has another hose fitting, probably 5/16", that hose runs up to the intake manifold drivers side and connects in a tee fitting that also goes to the EGR. This hose has a filter and check valve in it also. There is actually a GM part for this hose assembly, Shoebox may have it on his site. I bought a replacement cap at Autozone that came with the hose connection on it, I don't think you want to add one to a cap that doesn't have one.

Also, while you are in there, the water pump is what will drown out and kill your opti when it fails. I drilled out the weep hole on the pump to 3/16" and installed a 3/16" 90 deg. plastic vacum hose fitting, put a couple of feet of vacum hose on it, and route it over to the steering rack, tie it off with a wire tie.... that way when the pump fails, the coolant will drip away from the opti to a noticeable spot.

things to do for awhile