Holley help needed. MAJOR FLOODING!! - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 08-14-2004, 12:04 AM
dirtydave's Avatar
Member
 
Join Date: Oct 2003
Location: so. cal
Posts: 35
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Holley help needed. MAJOR FLOODING!!

Long story short;

dropped in newly built 383 chev into my truck. On my first attempt to crank it, fire came out of the carb right when it started to turn over. After flames were put out, fuel was pouring out of the secondaries on my Holley 780 vac. secondaries.

I thought the flames were from incorrect timing but it is set right to my knowledge. I searched all through these forums just to double check and it's right on.

So I adjusted the float level down as far as I could, and checked my fuel pressure during cranking and it's right where it should be (6-9) psi. Holley said this pressure should be fine for my carb. The carb is clean and the needle and seat assemblies are new. Now when I try to start it, it does the same thing and when I stop cranking, fuel is now dumping out ALL boosters and flooding the everloving crap out of my engine!

any suggestions?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-14-2004, 01:00 AM
Member
 
Join Date: Aug 2004
Location: n.s canada
Age: 44
Posts: 31
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Major Flooding

If you changed floats the problem may be the floats them selves.Some floats are different even a slight difference may be making them bind.Give them a good look, if you have a vernier caliper check the measurements.Best of luck.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-14-2004, 01:02 AM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,658
Wiki Edits: 0

Thanks: 15
Thanked 60 Times in 57 Posts
yes, lower the fuel pressure back to about 4 psi as a starting point. Holley likely forgot to add some times they`ll accept higher fuel pressure and some times they won`t. if it seems okay afterwards, break the engine in and set the fuel pressure around 5 psi or possibly 6.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-14-2004, 01:27 AM
dirtydave's Avatar
Member
 
Join Date: Oct 2003
Location: so. cal
Posts: 35
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
ok here is where it gets a bit more confusing for me.

I put this same holley on my old 305 just to see if it would crank and run before I swapped in the 383. It ran fine with no hitches. I haven't done anything different to the carb since then.

Doublevision, I think you're right when it comes to the fuel pressure. I just took out the holley mech. pump and put in the old stock pump to bring down the fuel pressure (i don't have a pressure regulator so this is the only way I can think of bringing it down right now)

still has a hard time starting and when I stopped turning it over, I took a peek into the carb and saw fuel pouring out of the secondaries again. so I took off the fuel bowls and re checked the needle and seat assy along with the floats. looks fine to me.

what causes fuel to just dump out for 30 seconds after I'm done cranking the engine? Also, I'll get a backfire through the carb once in a while when trying to start up. can the crazy flooding cause this at all? I would think not but what do I know?!

thanks for your responses
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 08-14-2004, 03:24 AM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,658
Wiki Edits: 0

Thanks: 15
Thanked 60 Times in 57 Posts
When I did the engine swap in my cutlass, I used a stock pump, I had all kinds of fuel pressure problems, fuel would pour out of the boosters, out of the top of the carb, it even did as you discribed, I got a gauge and checked the pressure, it was 14 psi, completely unheard of for a stock pump. I tried several different stock pumps and they all did the same thing, so I had to get a regulator, when a carb starts pouring fuel out of the boosters the first thing you should suspect is the fuel pressure, since the carb ran fine on another engine then it has to be the fuel pressure, it rules out anything else, since nothing is wrong with the carb`s floats and there`s no trash in the needle and seats, that only leaves fuel pressure as the problem since it`s all that`s left that can overcome the needle and seat. The problem with my car was the vapor line, I had to remove the carbon canister to install a sbc, and the canister was on the passengers side, I plugged off the vapor line which caused it to build pressure in the tank and the fuel pressure would rise until it overcame the carb, it would even hold pressure after the engine would shut off, just as yours seems to be doing. I took the cork out of the vapor line and the pressure returned to normal.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 08-14-2004, 06:39 AM
Member
 
Join Date: Jun 2004
Location: Kentucky
Age: 28
Posts: 45
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Also have the Power Valve checked, if the carb has backfired you very well could have blown P vlave and that would also cause an overload of fuel.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 08-14-2004, 06:58 AM
GoneNova/406's Avatar
Member
 
Join Date: Aug 2003
Location: columbus,ohio
Age: 59
Posts: 1,163
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
is your dist. in 180 degree's out ?its a very common mistake.i've done it .after being down for long periods of time you sometimes forget things.when i tear down that far i always start at tdc on # 1 after making that simple mistake once or twice.and after it backfired did you check your power valve.i know the newer 750's have blow out protection,mine does but i don't believe the older 780's do.i'd bump it around after fixing the carb and bring it up to tdc on # 1 and look to see if your rotor is pointing to #1 on your dist.cap.if it isn't pull the dist. up and look at the slot in your oil pump shaft and be sure its pointing between 5/7 cylinders,if it isn't use a long screw driver and make that change in slot direction,drop dist. back in and the rotor should be pointing to # 1 on your dist. cap.providing your carb. is fixed and you primed the oil pump while you had the dist. out, you should be ready to go.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 08-14-2004, 07:48 AM
King of my Man-cave.
 
Last photo:
Join Date: Nov 2003
Location: Michigan
Age: 55
Posts: 2,899
Wiki Edits: 0

Thanks: 3
Thanked 15 Times in 12 Posts
Adjust the floats with the engine running so the fuel just wets the bottom threads of the sight hole. Anything more than that will cause it to flood. I would also look over the needle and seats VERY carefully. It doesn't take but a SMALL bit of debris to cause major flooding. Plus, anyting more than 4-5 lbs of fuel pressure can make a small flooding problem bigger.

tom
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 08-14-2004, 01:52 PM
dirtydave's Avatar
Member
 
Join Date: Oct 2003
Location: so. cal
Posts: 35
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Ok I'm making progress but I'm not there yet.

Doublevision: Good call on the tank vent tube. I had a piece of tape over the opening so nothing would fall in during the engine swap. I forgot about uncovering it.

machine shop tom: I took out the needle and seats again and inspected and cleaned once again. I adjusted the floats again and put er back together. (i would adjust it when it's running but it's not running yet. ha ha)

There isn't anymore backfiring through the carb and the extreme flooding has stopped!!! It will just crank without starting. As soon as I turn it over it starts to make an effort to sputter but then it's just the sound of the starter again. I triple checked the timing. All is good there.

Is it possible that it's still flooded really bad inside? I had a bunch of gas pour down the intake last night from the flooding prob. How should I correct this. I'm also afraid of breaking in the cam with a possibility of gas in the oil.

Any more suggestions? Oh and to Unixkid and GoneNova, I put in power valve protection when I rebuilt the carb.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 08-14-2004, 07:35 PM
Member
 
Join Date: Jul 2004
Location: San Jose, CA
Age: 45
Posts: 138
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Remove the spark plugs and turn her over a few times without touching the gas petal to air out the cylinders. Maybe let her sit for an hour or two with the plugs out to dry.

Then try starting again.

Oh, also, check if the plugs are wet with gas.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 08-15-2004, 07:11 PM
dirtydave's Avatar
Member
 
Join Date: Oct 2003
Location: so. cal
Posts: 35
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I just wanted to thank eveyone for their help and that I got her started. I blew all the gas off of the plugs and let the cylinders air out for a while.

She still had a hard time starting but a squirt of starting fluid helped her get going. It spit out the carb a couple of times and flames shot out once but it seemed to smooth out as long as I didn't let my rpm's drop too low. I advanced my timing a little more and that seemed to help as well. Unfortunately some crazy overheating prevented me to properly break the cam in. I had to shut her down because of a small fire. I hope that didn't mess the cam up too bad.

But now on to bigger and better problems.......a loud low end knock through all rpms and all temps. My investigation begins as soon as it cools down.

thanks again to all
Dave
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 08-15-2004, 11:21 PM
80MalibuBC's Avatar
New Member
 
Join Date: Mar 2004
Location: Pitt Meadows
Age: 29
Posts: 16
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
not good sounds like the engine could be the problem if oyu have a knock with a brand new engine
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 06:02 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.