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Help!! Plenum Removal 86 quad

3603 Views 22 Replies 6 Participants Last post by  kredden
Ok I am trying to remove the plenum. I have removed everything the shopmanual says, except the brace from the engine mount. I cannot find the bolts that hold it. I can feel a 17 mm bolt on the bottom side of the plenum, I started to remove it and fuel came from the hole. Is this right. Please help, where are the bolts?

Also I noticed the motor mount is oval shaped, is this an after market mount.
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First, why do you need to remove the plenum? (mostly curiousity on my part)

I can't think of a 17mm bolt under the plenum with fuel behind it. (Doesn't mean there isn't one...) The plenum support is is like an upside down 'L', one end bolts on near the motor mount/starter brace, the middle supports the plenum on a pair of rubber isolated bolts and the other end bolts up under the intake near the engine. Are sure the bolt you loosened had fuel behind it and not coolant? Maybe there is a bolt under there that goes into the cooling system? The fuel rail is attached to the plenum by a bolt from underneath (smaller then 17mm I'm sure). But there shouldn't be any fuel behind that bolt.

I'm not sure about the motor mount. The ones I've seen were round.
did you remove the 2 13mm bolts on the bottom of the manifold..easy to miss, follow the throttle linkage down from the throttle butterfly there should be 4 hose clamps. 2- 13 mm bolts to the underside of the manifold.disconect the linage..( on y 84 you remove the oil vapor between the manifold and the fender)..also helps to remove the overflow bottle, to get underneath the manifold...remove the coldstart injector..and the small hose between the throttle buterfly..the vac hoses..and that should be it.. it will take some twisting to get it out thou.... call me at 916.529.7597..m car is outside the door..i will look if you want..
..oh yes.. on the support to the manifold the the motor.. 1 10 mm nut on the rubber thingy..thats. in the middle between 3-4 cly.
thanks for quick reply. I am rebuilding front suspension. The large bolt that goes thru the body and holds the upper A arm is hard to get to. I thought if I removed plenum it would make job much easier. Also thought since I am there I would change motor mounts.
OK, sounds like two good reasons to remove the intake plenum.

I still can't figure out what bolt you could have loosened to find fuel...
Me neither other than it might have been a pool in the plenum for whatever reason?

Still, 17mm is kinda a big honkin thing, at least AFA anything on the plenum proper is concerned other than the idle air bypass stuff.

I guess a picture would be the most explanitory.
cant post a pic because u cant see the bolt. I found it by feel. It is on the bottom side of the plenum about midway from front.
Hang on, going to take a picture real quicklike.

OK, attached is what the bottom side of the plenum off an 85 looks like when assembled. (as in it's all there, just not on an engine)

The 17mm ones are for the support brace (my error in the previous post, I thought they were 15mm) while the 13mm ones are for the throttle bellcrank support (you did uncouple the throttle rods didn't you?)


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Yes I did take the linkages off at the 2 points shown in the pic. Is it necessary to remove the two 17 mm bolts shown, or does the support inbolt at the motor mount?
tifosi.. is your car put together???:):):):)
yes take off the 2 17 mm bolts
Ah, that picture be worth more than 999 words...

I don't recall the plenum's brace as having 17mm bolts but it must be so. And if they pass all the way into the plenum's interior then it seems likely there could have been a pool of fuel to drip out. Certainly nothing under pressure.
no it was not under pressure, just dripped out. I can get the front 17mm bolt out, but I think you have to be a triple jointed midget monkey to get to the rear one.
If you don't take the two 17mm ones out, you have to remove the crossbolt at the mount and the single bolt that goes to the bottom of the actual intake manifold (you can see it peaking out next to the support arm in the attached)

The safer bet is to uncouple the rail support and remove the 17mm bolts as that'll give you the most wiggle room when removing and installing.

Going the other route can be seriously tedious when trying to reassemble, especially when it comes to that manifold nut.

(believe me, you'll swear enough just trying to get the rubber boots all lined up at one time)

Still, as you're working the camber arm, did you try form underneath, or removing the wiper washer resevior and radiator overflow bottle then reaching down through?

Granted it's working blind in both instances, but it's a lot less to put back together later.
tifosi.. is your car put together???:):):):)
Oh yes, but it looks like this.

I just happen to have the complete L-jet system sitting in storage boxes in the event I want to revert. (or take pictures for reference :D )
Oh yes, but it looks like this.
Gee, seems like you went through a lot of work just to get rid of a fuel rail someone painted red...
Yeah, but the new polished aluminum rail looks so much better so I guess it was worth it :D
I just replaced the inner caster bushing myself. It was a pain in the butt but I did get it off without removing anything in the engine bay other than the overflow tank. Long story short, remove the piece that the tie rods attatch to and has the bracket you can see on the inside of the wheel well. You will have to ppull the inner fenderback to get to the 3rd nut. If you have air tools, an impact w/ a swivel socket and extension should get you on the head of the bolt. A breaker bar with a 5" ext will get you on to the nut side. The bad part is that in addition to this being a lock nut, it has loctite applied which makes it pretty difficult to budge. I ended up putting a nut splitter on it and putting enough pressure to break the loctite grip. I didn't have to split the nut but it took about 350#s of torque to break it loose. It was pretty frustrating when I couldn't figure out why it wouldnt come loose but it just took patience. Oh, and if your putting poly bushings in, boil them in water before trying to sqeeze em through. makes it much easier.
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