How long to prime

longview · **Joined:** Tue Sep 25, 2007 3:28 pm **Posts:** 88

So, how long should it take to prime the fuel system?
I have been pumping that darn thing for an hour with lots of air, but no fuel.
What am I doing wrong?

Long Story
I finally got my fuel pump and wire harness. I took the whole thing apart, dropped the tank, removed the seat, blah, blah.
I decided to just swap out the entire wire harness. This means you need to unplug a connector from each wheel. These connector basically dont come off.
The little red tab that locks the release button breaks before it pulls out. Well, I thought no big deal, I just need to remove the tire to get better access to the stupid connector. That is when I find that the tire shop that put my new tires on over tightened the lug nuts with their 800000 PSI impact wrench. I broke my lug wrench and stripped one lug nut. No kidding. :evil:

So, at this point I am fuming. No real choice but to drive it some where to get the lug nut off so that I can get the tire off so that I can get the connector off.
Of course this means I need to put the tank back on.
I got that all done, but now I cant get it to pull a prime.

Cowcatcher · **Posted:** Wed Jun 25, 2008 11:42 pm

The manual says noth about opening the bleeder, just pump it and the CP5 is supposed to bleed off extra air. So if you are using the bleeder and not using a good 1)open bleed, 2)pump in, 3) close bleed 4) release pump, 5) repeat you might jus be recirculating air by sucking it in the bleeder. Try keeping the bleeder closed and see if you get pressure.

If none of that works then you have a major air leak between the tank and the filter head.

longview · **Joined:** Tue Sep 25, 2007 3:28 pm **Posts:** 88

I have been doing like the manual says, which is:
1) pump 20 times
2) open the bleeder to release air
3) close bleeder
4) repeat

I get lots of pressurized air releasing, which tells me the system is pressurizing.
I do this every week or two to fix the air-in-filter-head problem.
I just cant seem to get it to prime after having the tank off.

fastRob · **Posted:** Thu Jun 26, 2008 12:51 am

longview wrote:

I have been doing like the manual says, which is:
1) pump 20 times
2) open the bleeder to release air
3) close bleeder
4) repeat

I get lots of pressurized air releasing, which tells me the system is pressurizing.
I do this every week or two to fix the air-in-filter-head problem.
I just cant seem to get it to prime after having the tank off.

Did you hook up the connectors correctly? Pinched Lines?
How much fuel in the tank?
Did you change the filter too?

longview · **Joined:** Tue Sep 25, 2007 3:28 pm **Posts:** 88

As far as I can tell it was hooked up correctly.
There are only two lines to plug back into the fuel float/pump.
I did have the new pump already mounted in the tank, but still had the old wires.
Maybe you cant draw a prime through the pump like you could through the stock float?

I did not change the filter, and I had about 2.5 gallon of fuel in the tank.
Think it needed the fuel level higher?

I will be pulling it apart again after work today to try to figure it out.

dgeist · **Posted:** Thu Jun 26, 2008 8:56 am

longview wrote:

As far as I can tell it was hooked up correctly.
There are only two lines to plug back into the fuel float/pump.
I did have the new pump already mounted in the tank, but still had the old wires.
Maybe you cant draw a prime through the pump like you could through the stock float?

I did not change the filter, and I had about 2.5 gallon of fuel in the tank.
Think it needed the fuel level higher?

I will be pulling it apart again after work today to try to figure it out.

I had the same issue when I put mine all back together. The fuse for the pump had blown at some point, so I needed to prime it to get to the auto parts store. I probably pumped for 5 minutes (about 4 minutes longer than ever before). I could get it to start, but it wouldn't stay running. Finally, I just swapped the 20A fuse from the AC compressor in there temporarily. I know it doesn't help you, but at least you can still be confident that YOU didn't do anything wrong. I'd call the tire place and complain that you're stranded and can't get the lugs off and you'd like them to send someone out with an impact wrench to get the wheel off.

Dan

Uffe · **Posted:** Thu Jun 26, 2008 9:21 am

There's nothing wrong with your fuel lines or anything else for that matter.

Priming is just a PITA and you should get someone to shoot compressed air into your fuel tank while the bleeder screw is opened. Then prime 2-3 pushes and you're okay.

Cowcatcher · **Posted:** Thu Jun 26, 2008 10:15 am

Uffe wrote:

There's nothing wrong with your fuel lines or anything else for that matter.

Priming is just a PITA and you should get someone to shoot compressed air into your fuel tank while the bleeder screw is opened. Then prime 2-3 pushes and you're okay.

Isn't the fuel tank vented?

longview · **Joined:** Tue Sep 25, 2007 3:28 pm **Posts:** 88

Thanks guys.

I think I will hot wire the pump tonight to get the fuel lines charged.

dgeist · **Posted:** Thu Jun 26, 2008 10:30 am

longview wrote:

Thanks guys.

I think I will hot wire the pump tonight to get the fuel lines charged.

Yeah, just hang a couple alligator clips out the window and put some electrical tape around them and drive over to your tire dealer

Sir Sam · **Posted:** Thu Jun 26, 2008 1:26 pm

after the rollover I had to prime it a bunch, prolly a good 80-100 pumps..........

but ya, just a temp hot wire would be a good way to prime the system.

Uffe · **Posted:** Thu Jun 26, 2008 4:18 pm

Cowcatcher wrote:

Uffe wrote:

There's nothing wrong with your fuel lines or anything else for that matter.

Priming is just a PITA and you should get someone to shoot compressed air into your fuel tank while the bleeder screw is opened. Then prime 2-3 pushes and you're okay.

Isn't the fuel tank vented?

Probably only vented when the cap is put in.

If vented all the time what difference does it make to a closed system? There's just another filler tube then. And the pressure in the tank would increase anyway because compressed air needs tonnes of airflow to negate, which probably can't happen in a little vent tube.

I did the compressed air trick when I changed the fuel filter on my KJ - worked perfectly.

gmctd · **Posted:** Thu Jun 26, 2008 4:54 pm

I thought the idea of installing a lift pump was so the lp could prime the system?

longview · **Joined:** Tue Sep 25, 2007 3:28 pm **Posts:** 88

I got it all done.
My problem was just that I ran into a snag while changing out the wiring harness.
So, I basically had the old harness with the lift pump.
All is good now, and no priming required.

gmctd · **Posted:** Fri Jun 27, 2008 1:32 am

Good fix, then - now, keep an eye on the fuel manager head for any leaks resulted from previous operation

Goglio704 · **Posted:** Fri Jun 27, 2008 9:24 pm

gmctd wrote:

Good fix, then - now, keep an eye on the fuel manager head for any leaks resulted from previous operation

I would change the phrase "resulted from" to "revealed by."

SBosco · **Posted:** Sat Jul 05, 2008 9:37 am

Starting about 2 months ago I noticed that after atleast a few days of sitting, once in a while the jeep would not start. It would crank without any problems but not tuen over. I figured that it might have been a fuel problem and pumped the fuel system with the factory hand pump located on the filter assy. It started immediately after. This happened a handful of times. At the time I figured that I was a few thousand miles overdue for a fuel filter change and that might have been the problem. However, I changed my fuel filter about a month ago and it still happens.

Any ideas?

If I take it to the dealer, will they give me flak because I changed the filter myself?

dgeist · **Posted:** Sat Jul 05, 2008 12:05 pm

SBosco wrote:

Starting about 2 months ago I noticed that after atleast a few days of sitting, once in a while the jeep would not start. It would crank without any problems but not tuen over. I figured that it might have been a fuel problem and pumped the fuel system with the factory hand pump located on the filter assy. It started immediately after. This happened a handful of times. At the time I figured that I was a few thousand miles overdue for a fuel filter change and that might have been the problem. However, I changed my fuel filter about a month ago and it still happens.

Any ideas?

If I take it to the dealer, will they give me flak because I changed the filter myself?

The dealer would have no way of knowing that. Also, they cannot require you to have them do the work or void a warranty for that reason unless it's obviously done improperly. Regardless of the filter's status, it sounds like you have the dreaded air-in-fuel from a leaky system. Check the fuel heater plug for diesel (there shouldn't be any). Ultimately, getting this fixed is a crap shoot once it starts. The only real solution for folks that have air in fuel is to install a pump at the tank like there should have been from the factory. A good priming will get you a long way for now, though. Correctly cooling down the engine before shutdown also helps prevent air bubbles.

Dan

Dan

BVCRD · **Posted:** Sat Jul 05, 2008 5:30 pm

I bleed mine once every 500 miles. To do so, I pump 3 times so as not to blow out the heater wire seal, open bleeder, close bleeder, pump 3 times, open bleeder, close bleeder, and finally pump 3 more times and open bleeder a 3rd time to get nothing but fuel out.

SBosco · **Posted:** Mon Jul 07, 2008 9:12 am

So after the supplemental pump, I won't have this issue anymore? Can you give me more details? ie.) where most leaks occur, where the heater plug is, type and difficulty of installation of pump etc?

Thanks

How long to prime

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