leonpiper69

iTrader: (3)

I know Edelbrocks but not holleys.

I did a bunch of searching and bought a book on holley (that didn't teach me anything I didn't already know).

But I am trying to figure out why this motor is running so rich at idle.

I rebuilt the 750 DP and I thought maybe it could have been a power valve but my searching says they are almost never bad.

IT won't idle below 1200 rpm and runs pig rich (black smoke and you can reallllllly smell it), Plugs were dark black and wet.

Can timing effect rich/lean?

Doug G

What plugs and how old ? ....look rusty at the hex.

How many turns from seated are the idle air screws ?

How are the throttle blades set ?

Motor combo ?

How much vacuum is it pulling ? (PV may be to large ?)

Whats the timing curve look like ?

Carb jetting, PV size, squirter size ?

leonpiper69

iTrader: (3)

This isn't my LS motor (that one I use HP tuners on)

It is just a 350 with edelbrock performer rpm heads and roller rockers with a performer intake.

Car sat since 09 and I just bought it (74 bird) and it would not run when I got it. Those were the plugs I took out which ran like poop. I threw a fresh set in and fresh gas and then it would run fine from 2k rpm and up but would not idle and when I turned it down to 1200 (the lowest it would idle but rough) it was puffing black smoke.

all 4 idle air screws are set at 1 1/2 turns and the throttle blades are a little too far open but that is because it won't idle if I close them anymore than they are.

Vacuum I couldn't check yet (still just trying to get it to warm up, and I don't want to leave it idling at 2K running that rich because I am trying to avoid fuel washing the cylinders)

Timing curve I haven't checked yet. It has a billet timing cover and an aftermarket cheap stamped chrome timing pointer that may not even be correct. I am wondering about the timing because if the pointer is off then the PO would have set the timing wrong. I need to use a cyl stop and try to find TDC to even see if the timing mark is half way accurate.

The PV I put in it for the rebuild is just a 6.5

Jetting is 73 front and 80 rear and the squirters are 28 front and 31 rear.


Basically I am trying to chase why it is idling so rich for reasons other than the carb. I really don't want to just drop the money on a new edelbrock just to rule out the holley (even though I like edelbrocks better). I was realling hoping a bad PV was the culprit but after rebuilding the carb the old PV looks good.

When I tried to fire it up today after putting the newly rebuilt carb on it I had the rear float too hi and she was spurting fuel out of the rear vent tube. I quickly lowered the float (mind you it wasn't running) and it was trickling raw fuel into the intake so i called it a day because it was getting to cold to keep messing with it.

leonpiper69

iTrader: (3)

And you can see the motor is a little crusty from sitting but it should be a decent combo for a daily fun driver to I LS it.

TXsilverado

iTrader: (18)

tried going in with the idle screws yet? 1.5 is a starting point. Mine is more around 3/4 out (off memory)

Doug G

Mine are close to 3/4 turn out also.

leonpiper69

iTrader: (3)

Yeah I started at 1 1/2 turns and then went to one turn.

But I think my instincts were right to throw the holley into a wall and get an edelbrock.

The black smoke and richness was BEFORE I rebuilt the carb. I gave up messing with it yesterday because of the cold and fuel trickling into the intake.

So today I went to mess with it and it wanted to start and then it is still spurting fuel out of both vent tubes and trickling into the motor. I cranked the floats all the way down till the nut wouldn't even turn them anymore and it I continued to crank it and it still puked fuel out of the vent tubes and then got really hard to crank at all.

So I pulled the plugs and fuel POURED and I mean a continuous stream of fuel out of the #2 cyl......... I hope I didn't bend a rod!

I pulled all the plugs and whirled it over and fuel spit out of all the cylinders. I yanked the carb off and rinsed and dried it so I could bring it in the house later to take it apart tonight. So I am calling it quits for the day.

Doug G

What is your fuel pressure set at ? WOW.
6-7psi max.

leonpiper69

iTrader: (3)

I don't have an adj regulator. It's just a holley mech fuel pump. And it never puked before, just ran way rich

Brand new needle and seats from the holley kit too.

TXsilverado

iTrader: (18)

check fuel pressure and clean/replace needle/seat.

leonpiper69

iTrader: (3)

Well....She is ALIVE!!!

But I think I need a FPR. It's reading 9psi on the little moon gauge and that might be why I was having trouble.

I won't be able to touch it again till monday (doing a 3 day gunshow this weekend). But at least I made some progress.

I got it to idle down to about 1000 rpm before it starts getting real ruff. I need to lash the valves and then check the timing (though the timing feels about right).

leonpiper69

iTrader: (3)

This is the little fuel pres gauge I have on it. I will probably have to replace that whole setup to run a regulator.

What is the cheapest way to feed and regulate the 4150 ? I don't want to spend 500 bucks.

This is the one I am thinking about getting (just want to keep it small and cheap). But I don't see where the tap is for the gauge????
http://www.jegs.com/i/JEGS+Performan...5081K/10002/-1

Doug G

The one you posted says...
•Billet regulator mounting bracket
•3/8" stainless hard line
•Pressure gauge tap with 1/8" NPT plug <~~
•Anodized black fittings


Then this will work well also....
http://www.jegs.com/i/Russell/799/641100/10002/-1

and this

http://www.jegs.com/i/Holley/510/12-803/10002/-1

leonpiper69

iTrader: (3)

Actually it does say that on the bottom part but up top on the right it lists the part numbers and comes with the regulator too, all for 111 bucks. So I ordered a couple other fittings and hose while I was at it.

I will post some pics when it is done. It should be a small neat package.