Fuel Pump Eccentric

[3b a runnin]

My 360 in the cj5 totally died on me recently. After a little troubleshooting, I decided to change the fuel pump, because it would run with the electric pump, but not the mechanical. When I removed the pump, it seemed pretty simple.

install a new pump, and no better.
So I decide to tear it down and check the eccentric.

eccentric and all else in there is fine.
Since I don't know how to post a video, you'll have to take my word for it. The new pump is GARBAGE.
I clamped it in a vise and tried it and no vacuum at all.
The old pump with a bent arm would make 8 in of vacuum.
All this because of JUNK parts.
I'll never put one on again without checking it 1st.

 

[H Tate]

Can you post comparison photos so I can get an idea if my spare is good or bad?

 

[3b a runnin]

Yes I will
Wish I knew how to post a video
Basically clamp the pump in a vise, and attach a vacuum gauge to the pump inlet port. I clamped at the bolt boss. When you work the activator lever by hand, you should see some vacuum on your gauge.
Even my used one with a bent lever would pull 8in. of vacuum. Actually holding the lever down would keep the vacuum at 8in. until I released it. New one didn't even register on the gauge.

 

[Dave Deyton]

Had an old 56 CJ that the fuel pump died out on the farm. Tied an antifreeze jug to the windshield frame and drove it back to the house with gravity fuel feed. When I took out the fuel pump the foot had come off the lever. Pulled the oil pan and the foot was in the bottom of the pan. How it didn't hit something, I will never know. Just used it around the farm at my wife's grandparent's. That Jeep was so rusty the front seats were mounted on 2 X 6's.
The import aftermarket fuel pumps don't seem to be very good. Got a spare original rebuilt one on the shelf. The 53 M38A1 ran out of fuel and now won't prime. Priming lever broke off the fuel pump. May need to put on the spare and get ready to rebuild this one.
I wonder what vacuum is needed for the wipers. On both Jeeps the wipers work fine if the blades are not on the windshield.

Dave

 

[3b a runnin]

Perhaps someone would be willing to post this if I emailed them the videos

 

[Lilbuff63]

I’ve been having fuel pump problems on a friends AMC 258, been through multiple pumps with each one lasting varying amounts of time. Some would fail right away and others after a few miles. Don’t know if it’s a manufacturer issue or just old stock with bad rubber diaphragms. Pretty frustrating when you’re also dealing with a carburetor issue. I think he’s ready for EFI!

Perhaps someone would be willing to post this if I emailed them the videos

Only way I know how to post videos is through YouTube, Vimeo or another host site.

 

[jeepdaddy2000]

I’ve been having fuel pump problems on a friends AMC 258, been through multiple pumps with each one lasting varying amounts of time. Some would fail right away and others after a few miles. Don’t know if it’s a manufacturer issue or just old stock with bad rubber diaphragms. Pretty frustrating when you’re also dealing with a carburetor issue. I think he’s ready for EFI!

There seems to be a pleura of "new" fuel pump complaints, and not just with Jeeps.
I suggest a switch to an electric fuel pump. A lot cheaper than FI.

 

[3b a runnin]

Can you post comparison photos so I can get an idea if my spare is good or bad?

Just pics but here thay are
this is the old pump that had the bent lever just hook the vacuum gauge to the inlet port and stroke the pump
this is only 1 stroke and hold it

this is the new, AKA junk pump

and here's the latest new pump that I received tday from Jegs

all 3 pumps are the same MFG and same part number.

 

[44bz]

I ordered a new Carter pump for my 304 and the lever hardly moves at all. I couldn't even bolt it to the timing cover because the lever did not move enough to accommodate the eccentric. I didn't check the vacuum, but I'm guessing it wouldn't pull any.

 

[3b a runnin]

I could stroke the pump by hand, but the small pair of needle nose vice grips made it easier.

 

[3b a runnin]

And that pump was bad also
Before I got it together enough to get it out of the shop, it leaked.
Finally runnnin with a different brand of pump. Actually I'm using an electric pump for now.
I also swappped the Qjet out for the TA 470 that I had on the shelf. Driving it a little, and tuning a little.
Only good thing out of this circus, was I took the time to change the rear main seal while I had it apart, and it doesn't leak any, so far.

 

[3b a runnin]

I guess a little update is due. I've been really fighting this thing.
I kept having issues with the jeep dying in the road. Yea, driving along at 2k rpm or whatever, it would just quit!! Expected it might be the electric fuel pump, siince that was the last change.
Finally found a mechanical fuel pump at the local NAPA store. I had to do a little behind the counter help, but it worked. We eventually found a Delphi Tech, MF0042. This is a 2 port pump with the ports on the bottom. Some AMC pumps are inverted, but the fuel fittings won't clear the power steering pump on my jeep. This pump actually works great.
I could not do anything with the Holley TA 470. I give up and bought an Edelbrock AVS2 like this one. Edelbrock 1406 Edelbrock Performer Carburetors | Summit Racing
I got it mounted and runnin now. Still doing a little tuning, but it is probably 90% now. I consider that a WIN
Edelbrock offers a spring loaded needle/seat assy for this carb. for off road use and it showed up tday. I'll get to that soon.

 

[Jon B.]

I have a pump from a 304 that probably works. Do you want it? Whatever it costs to ship is what you’d pay for it…

I have no idea who made it.

Jon B.

 

[3b a runnin]

I have a pump from a 304 that probably works. Do you want it? Whatever it costs to ship is what you’d pay for it…

I have no idea who made it.

Jon B.

If its an old one, its probably better than the new ones. Yea I'd be interested
Let me know about shipping and such in a PM
Thank you Sir

 

[Fireball]

Edelbrock offers a spring loaded needle/seat assy for this carb. for off road use and it showed up tday. I'll get to that soon.

Other things that help Edelbrocks for offroading are blocking off the crossover between the bowls, lowering the float level a little bit, and regulating the fuel pressure to 3.5 psi. After those mods, the one on my '71 with a Buick 350 works pretty well at all angles. The biggest complaint I have with it is the fuel evaporating out of the bowls if it sits for more than a day. Since I don't drive it every day, It's annoying to have to crank it a long time to fill the bowls before it will start.

 

[T.M.]

Other things that help Edelbrocks for offroading are blocking off the crossover between the bowls, lowering the float level a little bit, and regulating the fuel pressure to 3.5 psi. After those mods, the one on my '71 with a Buick 350 works pretty well at all angles. The biggest complaint I have with it is the fuel evaporating out of the bowls if it sits for more than a day. Since I don't drive it every day, It's annoying to have to crank it a long time to fill the bowls before it will start.

You can always plumb a small electric pump in-line for priming. That's what I've done, and it works pretty well for me for priming the Jeep up when it sits. I also have a pressure gauge that's plumbed in just before the carb, so I can see when fuel gets up to the carb. Also would work if the mechanical pump gives me trouble and I need to get back home.

On the other hand, giving the engine a little time to crank does get the oil moving before it fires up. I think I remember NorCal69 saying that when I was originally discussing my fuel system plan.

Here's what I used: Keep in mind the pressure is high for carbs. I used this one because my Jeep has a regulator plumbed in.
https://www.summitracing.com/parts/sum-g3165

 

[jeepdaddy2000]

I give up and bought an Edelbrock AVS2 like this one. Edelbrock 1406 Edelbrock Performer Carburetors | Summit Racing
I got it mounted and runnin now. Still doing a little tuning, but it is probably 90% now. I consider that a WIN
Edelbrock offers a spring loaded needle/seat assy for this carb. for off road use and it showed up tday. I'll get to that soon.

I have a bit of a love hate relationship with the Edelbrock (called the AFB from here on out).

I ran a 500 for a few years and found it a bit inadequate offroad, The long float bowls tended to flood on extreme angles.

That being said, the ability to tune both the mixture and power circuit with the lid on is a huge plus and the lack of a vacuum diaphragm power valve keeps backfire fears at bay.

A strip kit will provide all the jets, needles and power circuit springs you should need for any tuning. It does require some math, as the needles aren't stepped proportionately (an issue I don't understand to this day).

IMHO, they perform really well on the flats and in most offroad situations, and are super simple to boot.

 

[3b a runnin]

It's been a while but here we go again. I've had 2, yes 2, Delphi mechanical fuel pumps fail in the last week. Both pushing gas out the weep hole.
Is it even possible to get this many bad pumps? Or have I got something else goin on with this engine? The fuel pump eccentric is the original, or at least I have never changed it.
What about an engine can cause 7 fuel pumps to go bad???
Help please

 

[iharding]

Regarding bad parts… I bought a new heat riser valve (exhaust flapper) that looked beautiful and appeared to operate perfectly. I was suspicious about how springy the operating coil was so I put it on the range and turned on the gas. It did not operate. The coil was a plain old spring. Not a bi metallic coil. Vendor didn’t care. Crown doesn’t care.

I had to buy a coil and struggle to install it because nobody else makes these.

it’s a sad state of affairs.

 

[timgr]

Call the Crown warehouse in Canton MA and and complain.