Need some help figuring out why my Holley 750DP is popping through the top of the carb. I just put new plugs and distributer cap and rotor button on. I have tested all the plugs wires to make sure they have fire.
the car was running really rich so I rejeted the front with 72 jets.
Any ideas guys

 

popping,like backfiring?

try adjusting/checking your timing and that your plugs are on in the correct order first.

 

I have checked the timing and its fine and the firing order is correct.

 

hmmm

well the popping from what it sounds like to be is a backfire.. if the timing is correct, and the plugs are on correctly, then the valve should be closed before it fires...... did you have the valve covers off to set the valve lash or somthing?

if you havent messed with the valves, and only changed the cap, rotor and plugs, and it was running fine before, i would be looking more closely at everything.....

ive actually seen cases where 2 burned out wires got close enough that the spark jumped from one wire to the other and fired the wrong cyl... did you move or re arrange the wires?


if you only changed a the ignition stuffs, i would look very carefully at them again, since your prob is probly there... trace each wire by hand...

 

The wires are pretty new MSD wires. They are not dry or have any cracks in them. I use zip strips in a way that makes it impossible to get the wire in the wrong place. I have an extra set of new wires here so I will try that first.
If its a wire I will smack myself because I did a test on every wire to make sure it was getting fire.

 

lol.. one time back in highschool, i was in a rush (near the end of the day) to get the car running.. i set EVERY wire in the wrong place... i still dont know how i messed it up that much.. lol

anyway, i turned the key and BAM! the air cleaner lid buckled for a sec, and smoke was drifting out of the air cleaner.. lol..

im just glad i didnt bend anything....

 

changed the wires and the carb is still popping out the top of it. Anyone else have any ideas?

 

ive got that exact same problem ive had the timing checked new cap and rotor new wires new plugs and it stil does it .it pops at the carb i ran for a little while with the filter off so i could see and when it popped a little puff of smoke came out of the carb..im trying a carb cleaner today..i was told by a friend that you can get a spray bottle and mist some water over the carb while your running itll clean the carb.with some backfires..dont know if its true gota ask someone here to see if that will work..if you figure it out let me know
thanks

 

I have heard of people doing that also. I did find out the problem with mine, my fuel pump took a ****. si I will be buying another one very soon. If your carb is running to lean it will pop thru the top like mine so I would check your jetting first.

 

thanks ill check that out today..ya it seems like everytime i get somthing fixed somthing else goes..just finished gettin the tranny rebuilt and a new clutch

 

Im having the same problem. Also here in ky.

Wires are good, plugs, rotor, and cap are new. Has an accel super coil. I am running a holley 750 vs #3310. This is on a stock 92 L98 with a wieand Team-g intake.

I just cant figure out the problem. I am running 5psi on the fuel and the front jets are 72. I have tried the timing at every position imaginable.

I just need to get this thing going.

 

I run my regulator at 7 to 7 1/2 P.S.I. and my timing at 38 degrees. You probably know this but when I set my timing, I set it with the engine running at 2500 RPM. 5 psi sounds to low to me.
I'm hoping that after I put in the new fuel pump my problems will be solved but who knows.
I sent 2 private messages to black84-6spdz28 but he never got back with me. He was having the same problem.

 

Well, I did some work on it last night. Even with the fuel at 5 psi, I had black smoke rolling out of the exhasut.

So we got to looking and it had a 31 squirter on it. I change it to a 25 and went from 72 jets to 70's. I also wired the back butterflys shut so it would run on the front 2. I took it out and ran alot better. It cleaned the plugs right up.

Looks like I will be getting a 4150 converson kit and a adjustable secondary diaphram.

It still has a slight mis. Just cant find it.