Moparchat - Home of MOPAR enthusiasts worldwide!



Go Back   Moparchat - Home of MOPAR enthusiasts worldwide! > Technical Forums > Performance Talk

Click here to search for Mopar cars and parts for sale.


Reply
 
Thread Tools Display Modes
  #1  
Old 02-03-2001, 05:18 AM
mopargator mopargator is offline
Inactive User
 
Join Date: Mar 2000
Location: huntington beach, ca
Posts: 16
Unhappy

I have a 70 Charger with a 383 with an Edelbrock Performer intake manifold and Edelbrock (Dog Poop)Performer 750cfm carb. Here's my problem...After installing these items a couple months ago, I had to pour gas into the carb to get it to start if the car sat for over 3 days. So I installed a Holley Blue electric fuel pump and bypassed the mechanical pump. This took care of my first problem, but now if I drive the car for over 45 minutes or so, or run some errands around town and start and stop the engine more than a couple of times, the car will not start!!! I have to let it sit for over an hour before it will start again. Acts as if its flooded. Why is this happening and how can I stop this. I plan on going back to a Holley carb, but this is what I have to deal with right now. Please help me!!! Thanks
Reply With Quote
  #2  
Old 02-03-2001, 01:47 PM
Christopher's Avatar
Christopher Christopher is offline
Inactive User
 
Join Date: Mar 1999
Location: fl
Posts: 2,018
Post

Did you install the regulator when you put in the blue pump?? If not,YOU MUST!!Otherwise you'll have way too much fuel pressure.And did you check the fuel pressure of the mechanical pump before you by-passed it?? A bad fuel pump can lose it's prime.Check these first.The Mopar/Carter Hp pump in the M-P catalog is a good hi-vol mechanical pump and works well.I have one in my 70 'Bird and it works great.
Reply With Quote
  #3  
Old 02-03-2001, 01:50 PM
rat roaster rat roaster is offline
Senior Member
 
Join Date: Dec 1999
Location: Alberta,Canada
Age: 65
Posts: 138
Post

The gasoline in your carb may boil if the carb is getting hot(after you shut off the engine)and flooding the engine. I had this problem and a Holley heat shield fixed it.I had a switch on my fuel pump and had to turn the pump off and on to make the car run untill the carb would cool off again. The gas would boil and overflow into the engine after I shut it off.Then the carb now with no gas left in it would get hotter and as soon as the electric pump filled it , it would boil over again.I would start the car with the pump off and cycle the pump off and on till the carb cooled off. The heat shield and thicker insulator carb gasket solved it for me.Next time you think the conditions are right for this to happen try starting the car with the electric pump turned off. Push the accelerator pedal to the floor crank the engine and as soon as it starts let the accelerator back to a lets say 2000 rpm and look for the signs off flooding like black smoke exhaust. I had a M1 intake and Holley carb on mine with big headers and alot of under hood heat. It was fine until I would run around town and then shut it off. Remember that a liquid boils easier when not under pressure and when the engine is hot and you shut off the pump (pressure source )and engine the gas will boil in the carb and dump into the engine.

[This message has been edited by rat roaster (edited February 03, 2001).]
Reply With Quote
  #4  
Old 02-03-2001, 04:41 PM
ehostler's Avatar
ehostler ehostler is offline
Registered User
 
Join Date: Jan 2000
Location: Annandale, VA
Age: 57
Posts: 15,212
Post

Your engine probably no longer has this, but all big blocks orginally came with a heat shield between the valley pan and the intake. It consisted of two metal shields and some insulation thta sat in the pan.

Most engines don't have a problem, when that shield is removed, but some do.

------------------
Ed - MoPower

'96 Dodge Ram 1500 SLT CC 360 4X4
'68 Charger 383-4
'69 Coronet 500 Convertible 440-4

[This message has been edited by ehostler (edited February 03, 2001).]
Reply With Quote
  #5  
Old 02-03-2001, 06:18 PM
64SAVOY 64SAVOY is offline
Inactive User
 
Join Date: Feb 2001
Location: monticello, MN
Posts: 2
Post

Had a similar problem like that with the same carb. You might want to see if the float bowls have cracked, heard these carbs are known to do that.
Reply With Quote
  #6  
Old 02-05-2001, 03:48 AM
PRO PRO is offline
Inactive User
 
Join Date: Nov 1999
Location: Grand Junction,CO.USA
Posts: 1,573
Post

For starters,if any car sits for 3 days and wont start unless primed it usually means that the gas is draining back to the tank due to a failed oneway valve in the fuel pump,also its likely that a fuel pump that does this is not creating ideal pressure,now the reason it wont start hot,its too rich,these 750 carbs have big jets in them,look at your plugs to verify but Ill bet there black,buy a stirp kit and get out your carb manual and rejet.Heres a baseline jet reccomendation. ,101 pri/.098 sec and 68x52 rods ........PRO....
Reply With Quote
  #7  
Old 02-05-2001, 04:18 AM
ben440brown ben440brown is offline
Inactive User
 
Join Date: Feb 2001
Location: Annapolis,MD,USA
Posts: 66
Post

Another problem I've had in cold weather with hard starting after several days is plugs that are too cold - especially with point-type ignition. The initial rush of fuel with the choke on washes out the plugs. Going to a hotter plug helps burn off the gas - really good for around town driving, too. In the Champion numbers, I run R15's in my stock 440 street car
Reply With Quote
  #8  
Old 02-05-2001, 05:52 AM
toolman toolman is offline
Senior Member
 
Join Date: Mar 2000
Location: Temecula, California, USA
Age: 61
Posts: 154
Post

Mopargator, I have had the same problem on my 383 with the Edelbrock 750 carb. The thick Edelbrock carb thermo spacer solved my restart problem. I was never able to solve the "start after 3 days problem". When I switched to a Holley and installed the larger squirter assembly up front, it always starts with one pump of the accelerator and turn the key. Fires up in one second! Even after two weeks!
Reply With Quote
  #9  
Old 02-06-2001, 04:27 PM
tucks 300
Guest
 
Posts: n/a
Post

Heres my problem, My ride used to start great after sittin afew days. But since my fuel pump failed and replaced it, after sitin afew days I have to dance on the pedal and crank the hell out of it to get it going. I replaced it with a same type OEM type pump. Whats the deal there?
Reply With Quote
  #10  
Old 02-06-2001, 05:19 PM
mshelly mshelly is offline
Inactive User
 
Join Date: Oct 2000
Location: Mountain View, CA USA
Posts: 92
Post

My Edelbrock carb/intake combo has hot start problems. I wanted to try a 1/2" carb insulating spacer but don't believe there is enough air cleaner to hood clearance.

The valley pan insulator Ehostler mentioned is something I've never seen. Anyone have a photo of one?
Reply With Quote
  #11  
Old 02-07-2001, 03:06 AM
road chicken's Avatar
road chicken road chicken is offline
Inactive User
 
Join Date: Feb 2000
Location: WI
Age: 58
Posts: 818
Post

Mshelly: That heat shield is basically regular insulation wrapped in tin foil. It was put there to keep the valley pan from cracking due to the heat from the exhaust crossover/heat stove thermal cycling/ work hardening the S.S. You can make one. It's about 6" X 6" X 1" thick. Just compress it right under the heat stove when you put the intake on. If you have the exhaust crossover blocked off, don't worry about it.

------------------
71 RR
97 SS/T

Move
Over
People
Are
Racing
Reply With Quote
  #12  
Old 02-09-2001, 06:27 AM
toolman toolman is offline
Senior Member
 
Join Date: Mar 2000
Location: Temecula, California, USA
Age: 61
Posts: 154
Biggrin

I have seen the heat insulation piece in a stock 69 coronet 383 car! It was the original piece soaked with oil and dirt. The owners never had their car worked on nor taken care of and that is why it was still there stuffed under the intake. It looked just like regular home insulation.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Fuel Problems scat70 Restoring your MoPar (Tricks & techniques) 5 05-20-2006 11:25 PM
Fuel problems, low filter? mrpoptart Performance Talk 13 01-31-2005 11:27 PM
fuel pump problems dodgecity Ram Truck Chat 7 09-02-2003 07:51 PM
Fuel Pump Problems big-nasty Diesel & Turbo Diesel Chat 5 10-27-2001 04:50 PM
Fuel tank/Fuel cell problems FarmBoy Performance Talk 4 04-20-2000 01:16 AM




All times are GMT -4. The time now is 08:00 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
. . . . .