electric fuel pump

[Wildcat385]

New to the forum. Just bought a CJ8 with AMC 304 and automatic. Have heard from a few people that my jeep will run better with an electric fuel pump. Was wondering if this is true, and what is a good brand to get that will be easy to install. Also wondering if there are any other easy mods that will help out my jeep. TIA.

 

[JR74CJ5]

:ww:

What does "run better" consist of?

Basically, what do you not like about how it is currently running?

Also as far as other mods,

What are your "grand plans" for this rig?

Do you want a road mannered and off road capable, Strictly on road / off road, etc.

Also if off road, do you like mud play, rock crawling, sand dunes etc.

Just helps us to know some suggestions on what would be sweet mods for you...



~ JR

 

[Wildcat385]

Mostly on road, but would like it to be off road capable. More than anything else, just feel it is a little underpowered. Didn't know if there might be any simple mods to gain a little power. Mostly will be used to run around the farm with the kids.

 

[JR74CJ5]

On the AMC 304 , I noticed a power gain with Headers.

Also a HEI distributor would be nice upgrade

Maybe throttle body / fuel injection mod (not sure you'd need that though)

Also what carb do you currently have on it?

Also have you done any tune ups yet?

If not, I would start with:

• Checking your timing
• Checking carb for leaks / tuning it
• Check spark plugs, clean and re-gap or replace (check gap when buying new)
• Check your distributor cap and rotor for corrosion replace or clean up
• Double check and re-gap if necessary the points in distributor.

If still a little underpowered for you, You can check the compression in the cylinders to see what you're getting.

These Motors (AMC 304 ) are a good powered motors when running right Don't know how much you know about them, so forgive me if this is redundant, but watch your oil pressure closely, sometimes the oiling system kinda sucks...



~ JR

 

[Wildcat385]

It has headers already, as well as HEI ignition. I have changed spark plugs. Wires looked almost new. I have not done cap or rotor, probably should. I had the timing adjusted when it got here from Florida. It wasn't off much, just changed it a little to allow for difference in altitude. What are your thoughts on the electric fuel pump? Also, it has an edelbrock carbeurator.

 

[CJim7]

Electric pumps are totally unnecessary on carbureted engines. The carb will only take so much fuel regardless of the delivery system. If you have a lack of power, its probably a different issue.

 

[JR74CJ5]

Electric pumps are totally unnecessary on carbureted engines. The carb will only take so much fuel regardless of the delivery system. If you have a lack of power, its probably a different issue.

X2... Unless maybe the fuel filter is a little clogged? possible? Also Air cleaner? those, if dirty, would / could restrict power production since they'd be starving the components (air & Gas)

Have you checked the compression of the cylinders? Not wanting to be fear spreading... just saying a possibility. I would think you'd be pretty peppy with those upgrades already... I would suggest double checking the HEI adjustments again, I'm assuming you have a different type of ignition system / coil system for it, maybe the spark is lacking? Did you re-gap the new plugs or just put em in? Might check that too...

Other than that, not too sure. What kind of edlebrock carb you got?

 

[CJim7]

Did you re-gap the new plugs or just put em in? Might check that too...

That's a mistake a lot of people make. TFI and HEI upgrades require a .045 gap vs. the OEM .035.
Is it running rich?

 

[Wildcat385]

It is running a little rich, and I know I gapped the plugs to .035. So I need to regap the plugs to .045?

 

[Wildcat385]

It is running a little rich, and I know I gapped the plugs to .035. So I need to regap the plugs to .045? Also not to sound dumb. Where is the fuel filter on a AMC 304 ?

 

[CJim7]

It is running a little rich, and I know I gapped the plugs to .035. So I need to regap the plugs to .045? Also not to sound dumb. Where is the fuel filter on a AMC 304 ?

Correct...045, that should make things work better
What you will have is an inline fuel filter...trace the fuel line from the carb to the fuel pump on the drivers side of the block, it (metal bulb) should be between there unless someone put one in a hard to get to spot...like down on the frame

 

[Wildcat385]

Thanks for all your ideas.

 

[CJim7]

Also...make sure you are running 8mm plug wires with the HEI

 

[BusaDave9]

I also have a AMC 304 and I installed an Electric Fuel Pump from Summit Racing. The reason was I had a bad problem with vapour lock. My engine would die when it got too warm. Then it could take up to an hour to get it running again. I tried every vapour lock "fix" out there. When I put in the electric pump it ran great. Fixed the vapour lock for good.
Let me also say; do not put in an electric pump unless you must. Everyone says an electric pump always fixes vapour lock but it was the last thing I wanted to try. Why? Because I think the mechanical pump is much simpler and for that reason much better and more reliable. If the engine is running the mechanical pump is being activated. If an electrical pump isn't working there are far too many things that could have gone wrong.
The pump motor could have gone out.
A fuse may have blown
The relay could be bad
And of course it could be a bad connection or ground.
It seems like every CJ has some type of electrical problem. With something as important as fuel delivery Keep It Simple!
When I got my electric fuel pump I also installed a clear fuel filter. When my engine is warm and I pull into the gas station I can see vapour bubbling into my filter.
I still have vapour but now my electric pump can still pump. A mechanical pump can't pump vapour. A mechanical pump is on the engine and it is not made to suck a vapour. The electric pump is back by the tank and can always push, even if there is vapour in the lines.

 

[CJKrawler]

Hey Busa, do you still have your mechanical for backup? How long did it take to shut down?

sorry to hi jack, but what you are saying might have something to do with my engine troubles. It's a 360, as far as I can tell, the only changes were a Holley carb and an electric fuel pump. I just got it, and am trying to troubleshoot a fuel delivery issue, where once I get it to start, it will only run for a minute. There was a fuel leak around the carb, so I am have the carb out. I am starting a new thread for those troubles, but I just wanted to give you a little background as to why I was asking.

 

[BusaDave9]

Hey Busa, do you still have your mechanical for backup? How long did it take to shut down?

CJKrawler, I threw out my mechanical pump a week after installing my electric.
My pump shuts down as soon as I turn off the ignition but the bubbling I see in my fuel filter is the fuel vaporising. It gets warm running under my jeep near my exhaust and into my hot engine compartment. This is also why it took me up to an hour to restart my jeep after vapor lock. The gas in the tank is cool. It warms up on it's way to the carburetor. When the engine shuts off the fuel sits in the hot fuel line under the jeep or in the engine compartment. that can cause more vapor.
If you have an electric pump vapor lock is less likely but still possible. I was told by a mechanic that there is no cure for vapor lock short of getting fuel injection. I am wondering if you have a problem with fuel pressure regulation. I will be looking for your thread CJKrawler.

EDIT: I see your thread now. http://www.jeep-cj.com/forums/f2/vacuum-line-help-pictures-10401/