Engine trying to shut down

[travis565]

I have a 78 CJ5 with a chevy 350 in it. It is my first jeep but not my first chevy 350. But i has a holley carb on it not sure of the size but it doesnt have the float adjustments on it. My question is when i brake even in neutral the engine tries to die out and its only when i brake not accelerate. I toom i on the trail thenother day and had to start it every obstacle i came to it smelled lime it was flooding out. The hills were not something that seems like it would aggravate the carb but are holleys that tempermental? I looked for other culprets to the dieing out but the only thing i can come up with is that the holley is that much of a premadonna or maybe the fuel pump isnt supplying enough fuel unless im pressing the gas pedal or letting it idle. Kinda weird but i figured id run it by you guys before i go replace that carb.

 

[Buuushman]

If you have power brakes, the booster works on engine vacuum- I'm not sure on the internals of the booster, but it is prolly causing a vacuum leak that is killing the motor.

Bush

 

[Old Dog]

I took it on the trail the other day and had to start it every obstacle i came to it smelled like it was flooding out. The hills were not something that seems like it would aggravate the carb but are holleys that tempermental?

Sounds like the float is set to high.
And yes holleys are that tempermental.
Go to the junk yard and get a 5.7 TBI and put on it, you won't be sorry.

 

[travis565]

Ill definately chase the vacuum lines for the booster down see if there are any cracks or anything and ill check into the tbi vegas is crappy as far as junk yards but maybe ebay or craigs list.

 

[travis565]

Is there anything else to do besides swaping the carb with the tbi? Computer or anything? I found a remanufactured one on ebay for 100 bucks. If thats it im going to buy it

 

[Buuushman]

If it dies in neutral when you hit the brake, it really sounds like the booster. If it's bad, you should be able to hear the booster sucking air when you hit the brakes. It's also pretty easy to change out. I.M.O. it's not likely the computer is bad, I'd do a little more investigation before throwing parts at it.

Bush

 

[Buuushman]

B.T.W- If it only happens while moving or on inclines Old Dog is right- pull the bowls and set the floats, I've had my Jeep with a Holley in plenty of off camber and steep situations and never had a problem with it.

Bush

 

[Old Dog]

Is there anything else to do besides swaping the carb with the tbi? Computer or anything? I found a remanufactured one on ebay for 100 bucks. If thats it im going to buy it

Like Buuushman said, if it dies anytime you hit the brake, check the booster.
If it's on bumps and hills than the float. You usually need to set them a littler lower for offroading than the street.
As far as the TBI you need the computer and wireing harness too.
Theres a couple good write up out on the web.
I just spent the extra money and got the kit from Howell.

 

[travis565]

Thanks guys
When i just press the brake pedal while idling the engine revs up a tad. Its only when im slowing down and by what you all are saying is its prob the floats. It is a non adjustable holley do you all know how to go about adjusting them by taking the bowls off? And i read today about hooking the vents together via a tube with a hole in the top to prevent flooding. Have any of you tried this? They said it was all the avenger did over a stock holley. Worth a shot

 

[Buuushman]

You should be able to remove the float bowl, hold the bowl upside down and see if the float is hanging horizontal(that is the top of the float is parallel with the inside top of the bowl). That's a good starting point. Some that are none adjustable you have to bend the metal.


Bush

 

[travis565]

ok cool ill try that on my next day off. thanks man so the object is to lower the level correct?

 

[Buuushman]

Depends on if it is flooding or starving- but making sure it is level with the housing should be the way it came out of the box and should work properly.

Bush

 

[travis565]

It's flooding it's leaking from every Venturi at idle and loading up. And I noticed what appeared to be small rubber fragments in the filter so I changed the fuel pump aparently it's been failing and now there is trash in the carb so I'm sure that's been the deal the whole time. Going to rebuild it tomorrow. We will see what happens.

 

[jeffgtoman]

You should find out what the fuel pressure is before you go any further. Get a brass fitting that will allow you to tee into the supply line. Attach a fuel pressure gauge to the new tee. Most carbs need 4 to 7 psi when the engine is running. Too much or too little fuel pressure will have the same affect as a float that is too high or too low. It is easier to test and repair a pressure problem than a float level problem.

 

[jeffgtoman]

You should find out what the fuel pressure is before you go any further. Get a brass fitting that will allow you to tee into the supply line. Attach a fuel pressure gauge to the new tee. Most carbs need 4 to 7 psi when the engine is running. Too much or too little fuel pressure will have the same affect as a float that is too high or too low. It is easier to test and repair a pressure problem than a float level problem.

I didn't see page 2 when I posted this. Sorry. You'll have to wait and test after you get the carb back together

 

[travis565]

Yea I'm hoping it's just trash in there and after I get it back on we will see. If it's a new pump it should be pretty much spot on I hope.