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vacum readings

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odd401 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote odd401 Quote  Post ReplyReply Direct Link To This Post Posted: Dec/11/2014 at 7:30pm
Cry i drove it to the shop that redid the intake and showed him the vacum readings when in gear,sprayed carb cleaner to try to find the leak,didnt change the idle,used propane into the oil fill tube to see if it would change,and no change,now i have lifters knocking on both banks and in gear my oil pressure goes to 10 psi,i think its gonna shell out again.im gonna plug the external distributor line to see if i get better pressure.i pinched the end inside so it would spray the gears so i dont know if it will help.changing out the power valve to a 4.5 instead of the stock 6.5 to see if that helps.and im gonna pull the egr valve,try another one cuz we have these stupid emissions here in north colorado.i hope it isnt something internal,this motor sucks compared to the first build,thanks for the advice
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odd401 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote odd401 Quote  Post ReplyReply Direct Link To This Post Posted: Dec/11/2014 at 7:39pm
Smile i forgot to reply,my truck is a 81 j-20 and it has a cat, i modified the heat riser,cut the butterfly out and welded the sides to make it look stock,new cat, edelbrock shorty headers and a flowmaster 2 1/2" in,dual 3 " out so it flows good,but now it has no power,my trans doesnt shift like it used to as well.hope i can walk tomorrow,been on crutches all week so not much work is getting done.
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gremlinsteve View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote gremlinsteve Quote  Post ReplyReply Direct Link To This Post Posted: Dec/11/2014 at 7:50pm
Lifters making noise?

Did they replace the cam and add new lifters?
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odd401 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote odd401 Quote  Post ReplyReply Direct Link To This Post Posted: Dec/11/2014 at 9:18pm
yep,its all brand new,comp cam and lifters,10-216-5,comp roller tip rockers,comp .100 long push rods,rocker studs.new cam,rod and main bearings, rings,pistons were good . new distributor,a holley 670 truck avenger carb, holley fuel pump and regulator, filter and fuel lines. ive got about 150 miles on it.hope i can work on it tomorrow.redo the power valve and figure out where the oil is leaking,getting oil burning smell in the cab at about 3500 rpm.not sure whats going on.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Dec/12/2014 at 10:03pm
You might want to block off the EGR temporarily anyway. That will at least eliminate it as a vacuum leak. If it's leaking you may be able to clean the seat and use it, but it may need replacing. 
Frank Swygert
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Boris Badanov View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Boris Badanov Quote  Post ReplyReply Direct Link To This Post Posted: Dec/13/2014 at 8:02am
I blocked a few EGR's internaly back in the 80's
so it looked like they were in working order
when they did nothing, although the valves functioned.
 
 
Gremlin Dreams
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Boris Badanov View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Boris Badanov Quote  Post ReplyReply Direct Link To This Post Posted: May/17/2015 at 4:26pm
BUMP
Gremlin Dreams
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Post Options Post Options   Thanks (0) Thanks(0)   Quote purple72Gremlin Quote  Post ReplyReply Direct Link To This Post Posted: May/17/2015 at 6:04pm
You have alot of problems. And you ha ve gotten good advice which you have not taken, and you give me the impression that you read what you want to read.
And you need to write better. Its hard to read what you say.
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uncljohn View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote uncljohn Quote  Post ReplyReply Direct Link To This Post Posted: May/17/2015 at 6:41pm
I just sort of went through a bit of what you are now doing. With pretty much the same symptoms. The only difference was instead of paying some one to screw it up I did it myself and a whole lot cheaper.
I errored in two places. When I rebuilt the distributor I made a mistake in assembling it. The second problem was a vacuum leak and while I could not work on it all the time, it took me a couple of months to figure out what was leaking. But the symptoms were the same, seemingly the timing had to be advanced to ridiculous numbers and the idle had to be cranked way up to get it to run.
Slowly I verified pretty much all of the things that has been discussed, but again, I did it myself rather than pay some one else.
When I found the distributor problem I was surprised the thing even ran, but it did. But fixing it did not solve things, because there was still a vacuum leak. And I could not find it.
The location of the leak I found by accident. On an AFB there are two connections for the PCV valve, one in front and the other in back. On some AMC intakes this is done with a carburetor spacer. The back one, (hard to see in the car) a plug, would blow off from a back fire as soon as he car would start. As it was hard to see and I would not look too often under the hood, up and behind it some times stayed off for day until I would find it, wonder why and put it on. The next time I started, blow it off again. With no exhaust I could not hear the hiss.
So did not look. One day I did. Fixed the leak. put a small hose clamp on the plug, now it idles at 700 rpm, the final tune is still not done, the timing is roughly 10degree's b4 top dead center and the vacuum reading is about 9 inches and steady. I have a cam with a fair amount of overlap on it. I think you still have a vacuum leak, but like some one else said, you are not really giving good solid information as to what your are finding. If the vacuum is still actually going to zero and bouncing between there and 10 inches, that is a major leak some where.
I do not understand the reasoning behind the loss of the distributor drive gear, other than it is I believe a hypoid gear and very sensitive to the amount of pressure applied at the mesh point. Too much pressure will eat the gear. I have played this game for a lot of years and the directions given by people to relocate a gear from one distributor to another are sketchy at best. But that may be exactly what is happening.

This is an installation instruction for installing helical distributor drive gears:
Distributor Slip Collar Benefits
The adjustable distributor slip collar allows you to compensate for variations in machining of the
engine block, intake manifold or heads. The adjustable collar will ensure that you obtain the
correct distributor to cam gear mesh as well as the oil pump to distributor shaft overlap. Once
adjusted, the slip collar needs to be locked securely in place around the distributor housing.
Adjusting The Slip Collar
1. Loosen the slip collar and insert the distributor into the engine until it bottoms out agains t
the oil pump drive.
2. After it bottoms out, raise the distributor 0.010” – 0.030” then slide the slip collar down
into position and tighten it.
Checking Gear Mesh
It is recommended to check for proper gear mesh between the cam gear and the distributor. To
do this, coat the distributor gear with moly grease and install the distributor. Next, crank the
engine and pull the distributor out. The gear pattern will show in the grease. The proper mesh
will leave an even pattern in the middle of the gear. Adjust the slip collar to obtain the correct
pattern of the gear mesh.

If the mesh is not correct, than the gear gets eaten up. Ether once installed, the distributor is adjustable for height, thus mesh can be adjusted or shims have to be used.
Or the distributor itself has a means for compensating for mesh thus height automatically.
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