Bringing a 1977 Z back life

[siteunseen]

And it's supposed to blow out from the valve cover to get circulated back through the intake.  It connects on the big rubber accordion hose before the throttle body.

Something I ran into that was a pretty good vacuum leak was my dumbass putting the valve cover gasket on upside down.  At the front where the thermostat housing bolts on to the head is straighter than the passenger's side.  You'll see it sticking out above the thermostat housing if I remember right.

[Av8ferg]

ZH, I’ll check all that and see what I find.  The sound almost leads me to think a intake valve might not be on the closing and on the compression stroke th I’m getting blow back.  Is this possible?  I guess the fact that my compression checks were good other that #4 @ 145 Psi.  If a valve were stuck i guess it would be close to zero. 

 

[Av8ferg]

Cliff, I didn’t know vacuum leaks could make such a difference.   I’ll get those sealed up.  Since we’re on the topic of vacuum leaks, any idea where this hose with the little dohickie attached goes?  I’ve cirecled it in green on the pic. 

[gwri8]

Here's a shot of my stock 77' engine for a comparison.  Mine does not have the check valve (dohickie) that yours does. If I recall correctly, the FSM calls for one there?

This page shows it attaching to the Thermal Vac Valve.

Edited March 16, 2018 by gwri8
Added FSM page

[Dave WM]

so you are not getting spark at the plugs?

[rcb280z]

1 hour ago, Av8ferg said:

little dohickie

That gets its vacuum source from the Thermal vacuum valve. Look under your AAR, there should be a "block" with 2 coolant lines running to it, if the PO didn't remove it. The AAR sits on top of that. At the end of the said block (cant remember its correct name) there is the thermal vacuum valve with 2 vacuum ports. One goes to that check valve you mentioned. That is not going to affect starting the vehicle. Its something you can address at a later date.

 

Just noticed in post 47 that check valve is connected but now it is not.

Edited March 16, 2018 by rcb280z

[Av8ferg]

My car had a CA title when I bought it. Title was from 1998. Maybe it’s an original California car and those had that vacuum delay valve.  

[Av8ferg]

I may have pulled it when I removed the fuel rail to clean it. Thanks for the info.  

When I pulled a spark plug and attached the spark wire to it and had my buddy crank the car I was getting a spark across the plug.  

[rcb280z]

51 minutes ago, Av8ferg said:

I was getting a spark

How good of a spark. Should be a nice blueish strong looking spark.

To me, when I watch this last video, your timing is way off. What have you done to check it? You could bring number 1 piston up on compression stroke and see if the distributor rotor is pointing to number 1 plug wire. IIRC.

[siteunseen]

I can't remember if you've said this already but will it fire with starting fluid?

[Av8ferg]

29 minutes ago, siteunseen said:

I can't remember if you've said this already but will it fire with starting fluid?

I need to buy some and will try when I get back.  

[siteunseen]

10 minutes ago, Av8ferg said:

I need to buy some and will try when I get back.  

You could shoot it down that hose off the valve cover but make sure to open the throttle blade so it'll get into the intake manifold.  Roll the throttle rod to the driver's side fender to open it up, squirt some in.  The reason I say that is you won't have to touch the accordion hose, those are begging to crack and expensive to replace.  Some people pull the brake booster hose off but then you've opened up the intake to unmetered air, aka "vacuum leak".