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persistent spark plug fouling

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Old Dec 29, 2018 | 03:32 PM
  #81  
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Could be a bad regulator.
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Old Dec 29, 2018 | 07:49 PM
  #82  
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Originally Posted by Rescue Rogers
Could be a bad regulator.

that's what happened to me, brand new Edelbrock billet regulator failed all the way shut, maximum pressure, flooded the carb and forced fuel past the needle/seats and flooded the motor, was horrible
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Old Dec 29, 2018 | 10:24 PM
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Originally Posted by Japery
I just installed the regulator(Holley 12-803) and tried to start but the gauge still reads 7lbs. I tried adjusting and nothing happens. Could it be the reg? It looks very cheap to me. Checked the plugs and they were drenched with fuel. When I turn over the engine the fuel gauge should read the 6/bs ,right, or does the car have to be running?
Yes...it has to be running.....

Jebby
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Old Dec 30, 2018 | 09:16 AM
  #84  
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So the gauge isnt giving an accurate reading at turning over the engine? If so I have more problems than a regulator. It really stumbles when running and not all cylinders are hot. Im thinking I should look at all the ground wires and maybe replace the module. It just really sucks that everything is bran new and it runs like this. Sooo frustrated now.
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Old Dec 30, 2018 | 01:00 PM
  #85  
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Cool cylinders indicate that a cylinder is not firing at all or not at the correct time (on the wrong stroke). How does that happen? Firing order.
Double check - triple check. Mis-ques happen to everybody. Start at number one on the distributor cap and trace wire to the #1 cyl. NEXT! #8 . . . . . .

At least you will know that part is correct.

Last edited by HeadsU.P.; Dec 30, 2018 at 01:03 PM.
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Old May 10, 2019 | 09:02 PM
  #86  
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Update on this rich problem. I had to tow it home from a local shop because he was clueless as to what was causing this rich condition. I have the car now at another garage with a litte more grey hair guys working on it (not that young mechanics cant fix it)and they are kind of stumped too. Anyone out there that can give me something that I can have these guys check. So far they checked the float and adjusted the pressure to 5lb.

Last edited by Japery; May 10, 2019 at 09:22 PM.
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Old May 10, 2019 | 09:37 PM
  #87  
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I just went back and looked at the post from the beginning. Did you return the regulator and get one that was working? Did you get that metal plate so you dont have a vacuum leak at the carb manifold junction? Has anyone opened the carb and checked the internals?

Im dealing with a lean problem/ dead cylinders problem right now after upgrading my cam and heads which is similar in frustration to your issues. I had to start over and make sure everything is double checked. I checked my valve lash, checked my compression, checked all my plug wires, checked my ignition spark, wiring order and called the manufacturer of the heads to get the correct spark plug info he recommends.

So my suggestion to you just start from the beginning and make sure you have adequate spark. That all you plugs are getting good spark at the right moment, and that you have a good fuel regulator. Try disconnecting the fuel all together and just getting it to run for a moment on starter fluid. THen introducing fuel to get it running again. See if you can eliminate multiple problems to make it easier on yourself. Thats why I went back and started over. I wanted to be sure I didnt have a flat cam or a cylinder with no compression and that the valves were set correctly so I can concentrate on the spark and fuel next.

If you can make sure your problem is carb and not ignition then you can concentrate on the carb. If its bad wires or plugs then you'll be looking in the wrong direction.
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Old May 10, 2019 | 09:51 PM
  #88  
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If you are running a HELI type distributor make sure you have 12 volts at the Distributor, Not the resistance wire feed of approx. 9.6.

Disconnect the PCV valve and see if you are sucking oil from there. Run the car with no PCV for a while.


I can't run Champion Plugs in my 72, they foul. My 1980 truck does the same. Why I don't know but they only last 1k miles or so in the truck. (yes they are the correct plug) The NGK last 10k+ miles.
I run NGK or Autolite most of the time.

Last edited by BLUE1972; May 10, 2019 at 09:57 PM.
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Old May 11, 2019 | 04:21 PM
  #89  
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Thanks for the responce. Yes. I changed the regulator and have the proper carb gasket. I dont think they checked the internals(Im guessing that means compression test)Im pretty sure its not the wires as i bought two sets back when i was throwing parts at it. Checked the coil and is fine.

Last edited by Japery; May 11, 2019 at 04:28 PM.
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Old May 11, 2019 | 08:05 PM
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An Autolite AR 3910 is not a hot plug by any means. Are you running NOS? I also believe you have a carb issue that is running way too fat since the plugs are black sooty. Once you square that away, throw a set of Autolite 3924 in there and it should be happy. The last digit on an Autolite is the heat range indicator. The higher the last number, the higher the heat range, zero is a very cold plug. If you are running a DUI coil, they say to run a widre gap at .055", I run .045" with the 3924 with my 383 and it runs just fine with a DUI coil and module in a GM dizzy. You can also gap them at .035 - .040" and be OK also. So, find your fueling issue and replace the plugs.

Last edited by Buccaneer; May 12, 2019 at 05:08 PM.
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Old May 11, 2019 | 08:54 PM
  #91  
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hvent read th whole thread. Put a stock plug and pump back on it

I run a very radical 383....stock gap, little bigger than stock pump no regulator no issues. Ck again.
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Old May 11, 2019 | 09:14 PM
  #92  
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A simple carter will do just fine. No need to buy a hp pump fell for that more than once.
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Old May 12, 2019 | 12:55 PM
  #93  
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Blueprint engines recommends champion 792 plugs. Im not sure what the difference is between racing plugs and regular. thoughts? I was always told to use what the engineers tell you to use but im not really going to race this car.

Last edited by Japery; May 12, 2019 at 12:56 PM.
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Old May 12, 2019 | 01:11 PM
  #94  
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If you had a leak at the carb gaskets the engine would run lean - suck in too much air.

The problem has to be too much fuel if the plugs are fuel soaked.

Go to AutoZone and get a $25 fuel pump for the motor. That should solve the problem.

Just be sure the floats in the carb are working properly.

Which carb exactly do you have for the motor and what jets are in it.
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Old May 12, 2019 | 06:09 PM
  #95  
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I have the Edelbrock 1905 AVS2 650 CFM 4 Barrel Carburetor and a new summit 7lb mechanical fuel pump.I realized later that 7lb was to big so I added a adjustable fuel regulator with a gauge so I could see whats going in. Mind you its at the 2nd mechanics shop and there not sure whats going on.Thinking it has to be something odd going on Right?
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Old May 12, 2019 | 08:50 PM
  #96  
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Originally Posted by Japery
I have the Edelbrock 1905 AVS2 650 CFM 4 Barrel Carburetor and a new summit 7lb mechanical fuel pump.I realized later that 7lb was to big so I added a adjustable fuel regulator with a gauge so I could see whats going in. Mind you its at the 2nd mechanics shop and there not sure whats going on.Thinking it has to be something odd going on Right?

1905 = It comes with: Metering Jets – Primary .101, Secondary .098; Metering Rods – .070 x .037; Step-Up Spring – orange (5" Hg).



Based on these specs I would think it's on the rich side.


the 1406 comes with .098 main jets and a .075 x .047 rods . which is good for most engines. As a rough guess I would say the carb is too rich and has to be de-jetted.

This is if the carb is getting 5 # of fuel pressure or less.


There is a chart in the carb box - I would de-jet the carb and see if the problem goes away.




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Old May 12, 2019 | 09:07 PM
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Oh cool. Thankyou for that info.Ill pass that on to the mechanic. If thats what it is should I get the tune up kit that has all the rods and springs?
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Old May 12, 2019 | 09:15 PM
  #98  
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Originally Posted by Japery
Oh cool. Thankyou for that info.Ill pass that on to the mechanic. If thats what it is should I get the tune up kit that has all the rods and springs?

If the carb is not damaged I would get the kit, you will need it to dial in the carb anyway...

Using the kit to lean out the carb will cost less time and eliminate some guess work. I would go 2 stages leaner and see if it improves.

Last edited by BLUE1972; May 12, 2019 at 09:17 PM.
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Old May 15, 2019 | 05:14 PM
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So I looked up a calibration kit for the AVS2 and couldnt find one.So I called Edelbrock and found out that they dont sell one yet and it will be available the end of June. So I tell him my story and he didnt think thats what I needed. The carb is set up perfectly for a 350 SB at sea level. I told my mechanic to call him and hadnt heard anything back. This car is driving me nuts.
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Old May 15, 2019 | 09:25 PM
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Have you swapped out the carb yet??? if you do that you can put that to rest one way or the other,,, you should do that because you keep coming back to that.. how many times can you rebuild it?... swap it, and be done with that path.
Spark... maybe,,, but still do not think so...
I still think your sucking oil from the plenum, or rocker studs.
Blue Print has come out and admitted they had some engines sold that were sucking oil through the rocker arm studs..
I don't think its gas, i thinks it oil, and you running lean enough and hot enough to burn the oil dry.
jmho
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