[25stevem]

Note that when a carb has the “ in the ball park “ primary jetting and the motor is fully warmed and out of gear you should be able to disconnect the accelerator pump and just about wing the throttle open in terms of the primary and get no back fires out thru the carb.

If you do then something is up with the carb or you have a vacuum leak.

[68WarDog]

[QUOTE=West Coast GTO;6339518]I degreed the cam BP6014SP dot to dot and found the cam has a 112 intake center line, not the 108 that the cam card says( or recommends). Does that mean I have to advance the crank +4 to get to the 108 intake center line that Comp Cams recommends ? Timing set has multiple positions.

Did you advance the cam? You mentioned multiple keyway timing chain. Have you checked your timing ?

[West Coast GTO]

Wardog:
Yes, I chose the correct keyway, then re-degreed the cam to get the correct 108 ICL. Checked the degree at ICL twice before installing heads.
BTW, I am using the "30-"30 cam valve adjustment procedure for setting lash.

[68WarDog]

BTW, I am using the "30-"30 cam valve adjustment procedure for setting lash.[/QUOTE]

I personally have never liked that method , especially with hydraulic cams. With a NEW engine. I prefer the valley pan be off, so I can confirm the lifters are on the base. Is it possible that some of your valves may be out of adjustment?

[West Coast GTO]

That actually kept me awake last night. I will adjust lifters again using the cam manufacturers method.

[25stevem]

Please everyone, stop talking about setting the lash, it's a Hydro Cam so there should be no clearance.

[West Coast GTO]

Well, this is really getting irritating.

I verified correct wiring order, adjusted the valves, verified cam does not have flat lobes( by the oil all over engine method), ATTEMPTED to set idle mixture on the Quadrajet idle mixture screws( and those didn't respond hardly at all) and sprayed starting fluid around carb, intake manifold at top, etc. with no change.
The good news is that the cam is not flat and the oiling system works very well.
I did note that the #3 exhaust lifter felt soft when setting zero lash and preload.

Anyone have any other ideas I can try?

[25stevem]

Well even if you do have a lifter that will not adjust right that will in no way cause the carbs mixture screws to do nothing, so with that being said I think you have found the cause of why the motor runs the way it does now, your Carb is either messed up and, yes you may have a vacuum leak taking place also.

An easy way to confirm a vacuum leak is to get the motor fully warmed up and then while at idle and out of gear slowly close off the choke.

If the motor then picks up rpm you have a vacuum leak taking place somewhere.

[West Coast GTO]

This is getting worse and worse.
I verified firing order AGAIN and changed plug wires( #6 and #8 had low ohm readings), checked correct ohm reading and wiring from magnetic contact at distributor, reset idle mixture screws on the Quadrajet to what they were set originally, tested for vacuum leaks by temporarily crimping vacuum lines( only difference was to PVC that wanted to kill the engine) and using a propane torch( unlit) at carb and upper/ lower intake manifold.
The car didn't want to set the electric choke at all, ran rough the whole time I was checking for vacuum leaks and backfired again thru the carb at slow off idle acceleration. Car was not very warm( 4 to 5 minutes running) when I tried to close off choke plate manually or with my hand, which made it want to die.

At this point, I just want to start buying parts( carb, distributor, coil, etc) in an attempt to find just what is causing this problem.

[68WarDog]

Originally Posted by West Coast GTO

This is getting worse and worse.
I verified firing order AGAIN and changed plug wires( #6 and #8 had low ohm readings), checked correct ohm reading and wiring from magnetic contact at distributor, reset idle mixture screws on the Quadrajet to what they were set originally, tested for vacuum leaks by temporarily crimping vacuum lines( only difference was to PVC that wanted to kill the engine) and using a propane torch( unlit) at carb and upper/ lower intake manifold.
The car didn't want to set the electric choke at all, ran rough the whole time I was checking for vacuum leaks and backfired again thru the carb at slow off idle acceleration. Car was not very warm( 4 to 5 minutes running) when I tried to close off choke plate manually or with my hand, which made it want to die.

At this point, I just want to start buying parts( carb, distributor, coil, etc) in an attempt to find just what is causing this problem.

Is it possible that you might have some bad fuel? When was your last fill-up?

[West Coast GTO]

I added 10 gallons of the 91 no ethanol to the tank before starting the engine for the cam break-in. That is the only fuel I use for this car. Previous fill up was last November ( same fuel).

[25stevem]

I am going to go way way out on a limb with this one so here it goes!

I have not gone all they way back thru this string to the beginning since you first posted about the car, but if you bought this car or the motor and your still running the same Cam, then maybe it's one that's ground with a 4 and 7 swap in the firing order?

[West Coast GTO]

I called both Comp Cam and Butler regarding the cam. Both verified that only the custom roller cams can come with swapped firing order at 4 and 7. Butler also recommended checking the new spark plug wires for correct ohm readings and also double check intake manifold to head junction for vacuum leak due to possible valley pan lack of clearance.

[PDC]

Have you got a friend with a known good distributor you can drop in for an hr just to test? I had Davis Unified HEIs on both of my traditional Pontiac engines and never had one ounce of trouble. As far as plug wires, I had great luck with Taylor Thundervolt with only 40 ohms/ft resistance. They make them in 10 mm and 8 mm which should fit in factory looms for an 'almost' factory look. I found that the Chevy Big Block pre-cut set fit a Pontiac block very nicely and routed over the valve covers as smoothly as any custom cut-to-length set could. I completely understand the folks who wisely caution against throwing new parts at a problem - but if you know a couple of plug wires are currently reading wonky anyway - I would consider dropping in a DUI HEI with a set of Taylor wires and fresh plugs to at least eliminate those variables - if not possibly get the car running right.

FWIW - I ran the exact cam you are using in my 455 with box stock D-Port E-heads. Jim Butler recommended the cam to me. Basically the XE-274 ground on a 112* LSA. I had mine nitrided for peace of mind and installed it with a set of Made in USA Johnson Hylift lifters. Car was running an RPM intake with a box-stock Holley 4150 750 cfm carb and Doug's headers. Had a DUI set up for 20* all in at 3,000 with 14* base timing. No doubt other cams would have made more peak power, but the car ran beautifully, made nice low and midrange power, sounded great and was a very enjoyable street driven car.

[West Coast GTO]

I ordered the thick intake gaskets today from Butler and will install them as soon as I get them and verify if any intake vacuum leak. I don't know anything about Quardajet carbs except how to set the idle mixture screws and I have a hard time believing the carb is the issue ( especially since Cliff set it up specifically for this car). In the meantime, I can get a new HEI distributor from a local vendor for $100 that will fire from the 6AL control box on the car. I don't have anyone around here that I can borrow a dizzy from( not alot of Pontiacs here in Northwest Idaho).
PDC: Good to hear about you liking this cam in your car. Mine sounded great during the cam break in at 2000 rpm.

[25stevem]

I would not blow the money right now on a new DUI.

Your symptoms do not seem to be related to that.

The simple fact that your carbs mixture screws do nothing leads me to say that you have a vacuum leak, or you have a clogged air bleed in the air horn of the Q-jet.

You would be surprised how fast this can take place with a Carb especially if it has sat over the winter!
I had this happen once and since I play Guitar I had some old strings sitting around of the needed small diameter to get down into the air bleeds and break up the dirt which I then flushed out with carb clean.

In fact many times all you need to do is flush out these bleeds with carb clean and then sit the carb upside down for a while and allow them to drain out.

I would pull the intake and set it back on the motor and 100% confirm that it sits flush and does not rock around without the gaskets there and if it does not modify the bottom of it such that it does not contact the lip of the valley pan,and then take it from there by looking at the carb like I just posted.

If you color up the bottom flange area of the intake with a big black marker and set it on the motor and slid it back & forth a number of times you will clearly see any contact issues with the valley pan show up.

You can use clay, play dough to the same end .

[West Coast GTO]

25stevenm: Can do and will do. Thanks for the ideas!

[25stevem]

keep at it, you will get it right!

[West Coast GTO]

OK, I followed all the suggestions listed above except doing a leak down test.
Cleaned the Quadrajet with guitar string, then flushed with carb clean. Put on a new thick ( .120) intake manifold gasket and relieved the aluminum valley pan for clearance( also viewed the wear pattern on the new cam-GREAT).
I now have timing at 18 degrees at idle( no vacuum can on distributor) with heavy silver springs on mechanical advance, idle at 800 warm with 12-13 HG vacuum and engine acts like it is lean/ shaking. Engine pops thru exhaust if too much advance at idle. CAR STILL BACKFIRES WITH OFF IDLE ACCELERATION.

I will admit that when I rebuilt the heads I did not check valve spring pressure, just cleaned and reassembled. I do have a new Brawler double pumper that I will install after I get the backfire problem solved. I also have a new( to me) 6Al control box with programmable advance options in case the old 6AL box may be going bad.

Any suggestions please?

[AG]

Disconnect the 6AL to eliminate that as a possible source of your problem.