93 LT1 intake the same as 94 LT1 intake manifold?

[TraceZ]

Just as the title says...

Are the manifolds exactly the same?

[TraceZ]

nevermind, I answered my own question..

93 intake manifold - p/n#12518284

94-97 intake manifold - p/n#12552137

So, what is the difference?

[bigtow]

hmmm great mindes thik alike i just posted somthing similur

[TraceZ]

hmmm great mindes thik alike i just posted somthing similur

Yeah. LOL.. And to further answer my own question, they are different because the 93 manifold has no provision for the 94+ fuel rail crossover tube.

[Z Ya Later]

Plus the 93 manifold doesn't have the port in the back for the EGR tube that everyone hates. Man I love having a 93

[pennylessz28]

It's shaped different too if you ever looked at the two of them side by side. Also the 93 isn't an OBD I car, its stil PCM.

[Z Ya Later]

Ummm, the 93 intake is shaped the same as the 94, minus the missing provision for the forward fuel-rail crossover. 93 is also OBD-I, since OBD-1 covers 82-95 on GM vehicles.

[pennylessz28]

Yeah, I got it backwords, the prom chips are different.

And they looked different to me last time I saw one. It looked more like the TPiS mini ram.

[Injuneer]

As far as I know, they are identical except for the fuel rail cross-over issue, and possible a slightly different contour for the rails themselves, because of the plumbing for the batch fire injector setup. If there is no EGR connection on the 93 intake, where does the EGR connection go to? As far as I know, the 93 has two connections on the passenger side exhaust manifold, one for the AIR and the other for the EGR, and somehow they are all hooked together???? I could be wrong.... never looked at the EGR on a 93, but the wiring diagram for the 93 shows an EGR solenoid, driven off one of the "quad driver modules" (another 93 oddball).

[Z Ya Later]

The 93 does have the EGR valve, but the tube that plagues the 94-97 is not there. How exactly does that tube work, if its fed into the intake manifold?

[Injuneer]

There is an internal "passage" between the flange where the EGR riser tube connects to the passenger side corner of the manifold, and the hole toward the drivers side of the manifold that the pintle from the EGR valve sticks into.

OK... on the 93 intake, is the EGR valve in the same location? If so, how does the EGR flow get to the EGR valve? Where does the tube from the passenger side exhaust manifold go to? Is the connection in the same place as in this photo?

[Z Ya Later]

The valve is in the same location, but I have no clue as to how it pulls in the EGR flow. Come to think of it, my 79 Jeep with the AMC 360 has the factory EGR valve but no tube from the manifold. I'd be interested to find out how it pulls the flow in as well. Off to the books I go I guess lol

[Overworked]

hey folks,

My 93 back looks just as the one above except the EGR is moved down slightly and to the Right (in the pic, Left facing front of intake). I do have a solid tube from the AIR connection that comes out and to the left.

The 93 is also different than the 95 as there is a port in front of the intake under the TB for the PCV hose. Will post some picks if anyone is interested. LMK quick as intake will be going on very soon (I hope)

[Z Ya Later]

Yes, pics would be great, thanks. I have yet to take mine off to actually look at everything (if the gasket isn't broken, why replace it lol).

[Injuneer]

They all have the hole for the PCV vacuum connection on the front of the intake manifold under the TB... the hole just has a pipe plug in it when the particular model has the U-bend hose that pulls the PCV vacuum from the port about 2" behind the valve, on the drivers side. There is not really a rigid line on which years connect to the port under the TB, and which ones connect to the port on the side of the intake, at least not in 93 and 94. Apparently there are variations based on what emissions regulations each car had to meet. The Chiltons manual has pages of vacuum diagrams showing both configurations used in the same year. There is a 3-letter code on the vacuum routing label on the radiator cover that tells you (along with the diagram) which emissions setup yor car came with.