Pulling the Plenum for the first time...

[Billy Mild]

I have had the ZR1 for a few weeks now and have driven more than I thought I would over these past few weeks. The no radio hasn't bothered me that much since I have some way of listening to tunes(phone with bluetooth speaker).

I have cleaned the grounds inside the car, but I know I need to clean the grounds on the engine block and anywhere else in the engine bay. I have been told that pulling the plenum is the right of passage to owning these cars.

I'm not a noob to working on cars in general, just corvettes. I have a guy local to me who went and looked over the car with me, let me know what I should do to get the car up to snuff. Pulling the plenum is on the top of this list to me.

List of things to do:
-Replace Fuel Injectors(don't know if its ever been done, but Tech 1 showed a big difference between the 2 banks of the engine)
-Fix some vacuum lines
-Change/flush coolant
-Change PCV rubber pieces
-Change MAP sensor hose(mine is all rubber not the hard plastic line like stock)

Is there anything I am really missing when pulling the plenum? Can I get some of these vacuum lines at the local part store? That MAP sensor hose is like $45 on Jerry's gasket. He told me to make sure I book about 8 hours to do all this work.

[Roadster]

I will be watching this thread, as this is something I may be doing over the winter. There is a wealth of info on this forum, these guys really know the ZR-1 inside and out. I am always learnng something new on this site, and learning more about my 94 as time goes on.
Be sure to take pics along the way, as it is always good to get another look at what owners are doing to their Z's.
BTW, what year is yours? And good luck!!!

[Billy Mild]

My car is a 1991. White with red interior.

I figured I would post this question on here in order to have all the parts lined out before I start tearing it apart.

[Schrade]

I didn't know this thing either when I started (still don't much ); but maybe put every bolt back in it's hole when the part is out of the way, which takes longer, BUT, bolts NEVER get mixed up when you do.

And, clean the parts as soon as you remove them.

Dirty parts stack up REAL quick; then at re-assembly, you get rushed, and don't do as good a job as you'd have done otherwise.

And no one gets mad if you post LOTS of snappics as you go

[XfireZ51]

Billy,

Just a couple of suggestions.

1. The BLM split between left and right banks is not unusual particularly at low airflow levels like idle. If you are going to swap out injectors, it should not be because of that alone. If you suspect something else fine. Also, depends on mileage.

2. If stock coils and wires then I would upgrade these.

3. You'll need to make sure you drain coolant to levels below plenum.

[secondchance]

When ignition is in run position how frequently and for how long does your vacuum motor run? If it stays quiet for 30 seconds or more I would say your vacuum lines are in good shape.
Also, I would have a couple of 3 way vacuum check valves handy just in case.
I would check all vacuum line plastic to rubber boot connections and if they are sliding relative to the other, I would slide the hard line out about a 1/4", dab of Crazy glue, slide back in. Also, seal the rubber boot shoulder with black silicone sealant followed by a zip-tie. 'Course all that is unnecessary on my car since I pulled the whole secondary vacuum off the motor now.

[Billy Mild]

Originally Posted by XfireZ51

Billy,

Just a couple of suggestions.

1. The BLM split between left and right banks is not unusual particularly at low airflow levels like idle. If you are going to swap out injectors, it should not be because of that alone. If you suspect something else fine. Also, depends on mileage.

2. If stock coils and wires then I would upgrade these.

3. You'll need to make sure you drain coolant to levels below plenum.

My car has 69,000 miles and to my knowledge has never had the injectors done. The car runs a little rough at idle. The local guy seemed to think it ran really rough for a ZR1.

They appear to be stock coils, and wires. It seems to be hit or miss with changing out coils.

Originally Posted by secondchance

When ignition is in run position how frequently and for how long does your vacuum motor run? If it stays quiet for 30 seconds or more I would say your vacuum lines are in good shape.
Also, I would have a couple of 3 way vacuum check valves handy just in case.
I would check all vacuum line plastic to rubber boot connections and if they are sliding relative to the other, I would slide the hard line out about a 1/4", dab of Crazy glue, slide back in. Also, seal the rubber boot shoulder with black silicone sealant followed by a zip-tie. 'Course all that is unnecessary on my car since I pulled the whole secondary vacuum off the motor now.

I would like to replace vacuum lines not just put a band aid on them. Where should I get the 3 way vacuum check valves?
My vacuum pump runs every second or so. So it there are some vacuum leaks.

[secondchance]

Originally Posted by Billy Mild

I would like to replace vacuum lines not just put a band aid on them. Where should I get the 3 way vacuum check valves?
My vacuum pump runs every second or so. So it there are some vacuum leaks.

Based on my experience, unless plastic lines are cracked and broken, replacing with new lines will only buy you time because heat and oil fume softens the rubber and makes the seal loose. Crazy glue, zip tie and sealant (or epoxy) on the shoulder is the permanent solution.

http://www.amazon.com/ACDelco-15-505.../dp/B0016I0E42

[Harvie]

Took me 3 hours to pull the plenum off a motor last night. Anytime I do something the first time I make or have diagrams and try to follow the service manual steps.

The throttle body extension is real fun getting off when attached to the engine. 25t 1/4 ext and fish

[Schrade]

Originally Posted by Billy Mild

The car runs a little rough at idle.

Not necessarily vac leaks...

It could be air getting by the 2' TB butterfly (which I suppose amounts comparably to a vac leak), but not entirely the same.

Cut a gasket withOUT cutting the 2' holes, to re-check idle quality. I did this, and idle was rock-steady. I'll put it back in, when I learn coding.