Well Damn..Vacuum problem
 

I dont have a vacuum gauge I am going to borrow one tomorrow. But my engine isnt pulling much vacuum.

I dont have any vacuum leaks and the car runs great @WOT.

here are my problems.

I set the fuel pressure @39psi @wot and when I attach the vacuum line the pressure only drops to 37 psi. So it is running rich at an idle.

Also my breaks are not working too great cause of the lack of vacuum.

I guess the E-cam is the problem:confused:

I do I fix this problem.

vacuum configuration...
 

Dark,
I have a GT 40 intake too. Tell me what you are drawing vacuum from and what things you have hooked up.

I have a b-cam with 1.7's and I've got plenty of vacuum. I have only the brake booster, pcv and fpr coming off of the lower tree of the GT 40. Everything else is plugged.

Hozer

I am running the brake booster off of the same line that goes to the pcv valve. And I have I line going to the fuel pressure regulator off of the big barb on the back of the intake everything else is plugged.

vacuum configuration...
 

I will give you my readings and vacuum psi tomorrow in return for your valve adjustment tips.

Maybe that can help you diagnose.

I think thats the reason your brakes arent working well. Run them off a dedicated fitting.

good call
 

I am running my brake booster line from a single large barb pulling vacuum from the port underneath the main runner from the throttle body.

My fpr and pcv are coming from thr two dinky lines coming off the tree underneath the main plenum by the driver's side valve cover.

I pull too much damn vacuum. I have to run a in line filter from my pcv so it doen's throw oil in the plenum.

I have always ran the lines like they are ran now without any problems. My problem is my engine is making very little vacuum.

I hope there is a way to fix it.

When I had the similar combo I pulled 11-12inches of vacuum.
I also had a dedicated line for the brake booster as well. Never had an issue with the power brakes either.
Either you have a leak or you do need a dedicated line to the booster. At least a 3/8 ID line.

I am going to pull the upper intake manifold back off tomorrow and see what I can find out.

Later,

Just as a baseline Dark...with my old 302 H/C/I combo (steeda #19 cam 480/480 lift with 115LSA and duration I can't recall) pulled 11-12 in-hg. at idle (750 rpm).

I'm not sure what you mean by the brake booster line - I've never touched mine.

E

My engine idles perfectly....The car feels fast when you drive it.

But here is the kicker...............My car isnt making enough vacuum to move the vacuum gauge at an idle.

If I rev the engine a little bit the gauge will go to 4 hg's.

You would think I have a huge vacuum leak but I have checked and rechecked everything over and over.

Upper to lower intake is sealed for sure.

Lower intake to heads is sealed for sure.

Hell if I know. This sux:mad:

Just out of curiosity, What is your timing at with the spout connector disconnected?

15 initial advance

Something has to be run wrong. I had a E cam for a long time and never had problems with vacuum. The brake boster runs off the vacuum tree right? I think maybe you blew a cap off somewhere or something. Your combination should have pleanty of vacuum.

I agree.

If you have near to stock compression I would try more timing to. I was always able to make more power running anywhere from 16-19 degrees. Each car a little different but same cam and similar parts. All had close to stock compression. 9 to 1--9.5 to 1.

If you can, post a pic of your vacuum tee and the hoses that goes to the booster and intake. Maybe one of us willl see something obivious??:confused: Worth a shot.

You sure you don't have a lower to head leak? It could be drawing from the crankcase and you'd never know it.

A huge vacuum leak should be audible if it's external...

Measuring vacuum...
 

Dark,
Where are you measuring your vacuum at?
We have nearly identical setups N/A and I have 10-11 inches of vacuum at 750 RPM idle. Measured at the fpr and at the GT40 tree under the plenum with a vacuum guage.
I am going to measure it at the big barb too for ya. I'll post it in a minute.
I agree with the pic idea too. That might make something jump out at everyone.

2 Things.
1st - Change the guage
2nd - Check the brake booster

Hope this helps a little?

Even if I plug all vacuum lines except for the one on the gauge I still dont get any vacuum.

I did a compression test just to make sure I didnt have a dead cylinder from setting the valves too tight and everything was fine 155-165.

The lower intake gaskets have got to be sucking air inside the intake valley.

We will see.