Help on a P0093

skywarn · **Posted:** Sun Aug 10, 2008 6:28 pm

P0093 Fuel system leak detected – large leak Wiring, fuel pressure sensor, mechanical fault

What is this?!?!?!?!?!

The last time I got this code I changed the fuel filter, and code and limp modes went away. Now i cant get this code to clear.

Yes fuel heater puck is still there, but there is no leaks around it
No there is no air bubble in filter, the bleed screw was bled over and over to be sure there was no air in the sys.
dont think it matters but the fuel cap tested good

And now i have no idea what else to check

onthehunt · **Posted:** Sun Aug 10, 2008 7:31 pm

Bad fuel psi sender,wiring or the pump itself. I'm guessing it has to do with your CAT filter. Make sure that's not on there when you try to warranty your injection pump.

skywarn · **Posted:** Mon Aug 11, 2008 9:04 am

well I'm out of warranty so what can I do to start trouble shooting this prob?

skywarn · **Posted:** Thu Aug 14, 2008 9:54 am

anyone?

gmctd · **Posted:** Thu Aug 14, 2008 1:33 pm

Lift pump................

skywarn · **Posted:** Fri Aug 15, 2008 2:27 pm

lift pump ea? where is that at?

and now to make it worse... im have to have to turn and hold the key for 4-5 sec for her to start... :evil:

last night it took 10 min for it to start.... arugh!!! :evil:

so back to the lift pump what should i be looking for?

bdptp73 · **Posted:** Fri Aug 15, 2008 2:53 pm

skywarn wrote:

lift pump ea? where is that at?

and now to make it worse... im have to have to turn and hold the key for 4-5 sec for her to start... :evil:

last night it took 10 min for it to start.... arugh!!! :evil:

so back to the lift pump what should i be looking for?

Go easy on him guys. :roll:

skywarn · **Posted:** Fri Aug 15, 2008 3:01 pm

i know i think i messed the whole lift pump thing... but the threds are so off topic its hard to follow....

JL Rockies · **Posted:** Fri Aug 15, 2008 3:05 pm

I agree with you there brother.

skywarn · **Posted:** Fri Aug 15, 2008 3:39 pm

lift pump aside, I dont see how i have gone over 80K miles and just now need a lift pump...

so lets say installing a lift pump does not fix this code. what should be looked at next? Just out of fear, im going to remove the fuel filter again tonight and check the heater puck again, then check it again before i recheck it and put it back in. besides this any other thoughts?

gmctd · **Posted:** Fri Aug 15, 2008 3:56 pm

It's likley vacuum-locking - big air leak between tank and fuel manager head, incl fuel manager head - can either replace the plastic quick-connects back at the tank with clamped rubber hose connections, or install a lift pump in-tank, at the tank, or at the fuel manager head, 'sup to you

Noting the home-brew placard, could also be something plugging up the supply line, tank forward, whereby the CP3 would be drawing up to 28"HG vacuum, and still no fuel

fastRob · **Posted:** Fri Aug 15, 2008 4:33 pm

http://www.lostjeeps.com/forum/phpBB3/vie ... hp?t=26385
This is the thread I used.
Think simple, I worried, agonized and fretted.
1. Order correct pump.
2. Go to stealership and humbly ask for a couple of ends male and female. one place they were free another $35.
3. Get enough correct wire.
4. Wait until tank is low.
5. Hardest part was moving the carpet under the back seat.
6. Ask if you need help, think that it cannot be this simple, yes it is.
7. The tank connectors are quick disconnect so there is no need to break them.

Recap: 1 pump, 2 3+ foot wires with correct ends male and female, $200. or less and 2 hours

GMCTD did the heavy lifting on this mod, a tip of the hat to him and his help.

ATXKJ · **Posted:** Fri Aug 15, 2008 7:02 pm

FYI - somewhere in the thread it also mentions swapping the float arm so that the fuel gauge will read the same (it was never accurate)

As to the initial question - you have a air leak in a vacuum system - probably due to the fact that molded plastic around the heater connector will fail over time - and start letting air leak in - the more air the more problems - the lift pump pressurizes the system - now if the leak is big enough - you might start getting fuel coming out with the pump, if that happens then you need to change the fuel head - dealer will charge ~$150 or so for a stock that will do the same thing - however a much better solution would be to change to Racor.
check out Stan's install http://liberty.eurekaboy.com/racor.htm

nescosmo · **Joined:** Sat Jul 14, 2007 11:17 pm **Posts:** 202

ATXKJ wrote:

FYI - somewhere in the thread it also mentions swapping the float arm so that the fuel gauge will read the same (it was never accurate)

As to the initial question - you have a air leak in a vacuum system - probably due to the fact that molded plastic around the heater connector will fail over time - and start letting air leak in - the more air the more problems - the lift pump pressurizes the system - now if the leak is big enough - you might start getting fuel coming out with the pump, if that happens then you need to change the fuel head - dealer will charge ~$150 or so for a stock that will do the same thing - however a much better solution would be to change to Racor.
check out Stan's install http://liberty.eurekaboy.com/racor.htm

Racor is the best way to go and to do the tank job for me it cost too much money. I went to autozone and bought a Master E8012S that is set for 6 to 9 pounds, but it give you in real world about 3 to 4 psi. I install it under the Jeep at about the back sit, do the wiring cut the lines and that was it. If the pump stop working the CP3 will still get fuel. That and the Racor the air and fuel issue went away. Also check your FCV it could stick use brake cleaner or carb cleaner to clean it.

onthehunt · **Posted:** Sun Aug 17, 2008 8:55 pm

Ooooh... I didn't see the 100% bio-diesel in your sig line. Definetly changes things. Take a fuel sample or pull your filter and cut it. Plugged?? If not, test your fuel system for leaks/obstructions and hope you find one as you are getting close to the big $$ zone. If you can't test the system just go down to the dealer and buy a $150 filter head that comes with a new filter and install and bleed. Hope it fixes it. If a lift pump fixes your problem it is just covering up a bigger one.

skywarn · **Posted:** Tue Aug 19, 2008 2:58 pm

Yes running 100% does change alot... the one thing i do like about the cat 2 filter is it will let you know when its time to replace it, hence the multi limp modes. which i had a lot of. but just like last 2 times i replace the fuel filter and all is good! no more limp modes and no more CEL. This time it was different, all went as planed, changed fuel filter, un hooked EHM and re pluged in ORM, CEL light went off. :wink:

then next day POW!!! P0093...

Ive called Racor and they flat out tell you that there product cannot and will not stand up to any bio blends higher than 5%. but they have had good luck with the stock CRD KJ fuel head... go fig ea? anywho, ive gone through the fuel head yet again, removed filter checked hoses, wires, and re attached. all looks good so far.

Im thinking on going to the dealer and having them look at it, then saying thanks as i drive off and fix it myself... but then again, thats just not right...

the reason i keep going around the lift pump is just what was said, the prob would still be there just covered up by the lift pump. Thus ill get the prob fixed then look into installing a lift pump. I like the sound of only $200 and easy!

BTW what is the FCV? and check if it needs to ber cleaned.... i dont know what that is...

Thanks for all the help!!! keep it coming! I feel that im soo close to finding this code!

Joe Romas · **Posted:** Tue Aug 19, 2008 4:53 pm

Flow control valve (FCV) is on the left side, drivers side in the US, of the engine with the big charged air hose connected to it. Take the 3 or 4" hose off and the butterfly valve is in there.

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

From Racor bulletin 7679, titled "Racor filtration and biodiesel."

"Racor uses materials compatible with up to 20% biodiesel blend. Above 20% biodiesel may require material changes to dynamic seals that are not normally changed at [filter] element change-outs."

If your contact was unaware of bulletin 7679, published in December 2006, it seems likely they didn't know the product line as well as they should have.
BTW, I have run up to B90 in the R490 and no less than B20 for over a year now without issue. When I added a fuel return cooler I used fuel line rated for biofuel (SAE J30R9) use.

Last year, I emailed the product manager at Racor with specific questions on the use of their 200 and 400 series filters with biodiesel blends greater than B20 up to B100, as to which of the seals would require upgrading. There are 2 seals on the filter, one for the filter head and one for the bowel and 2 O-rings on the bottom bowel, one for the drain and one for the WIF sensor port.
This was the response I received:

"Good Day, xxxx,
All permanent rubber parts in Racor filters are made of fluorocarbon rubber
(similar to trade name 'Viton').
Only the replacable rubber seals that come with service elements are
buna-n. These seals are essentially captured within their sealing glands
and any swelling would actually increase the sealing capability.
Regarding fittings, these are low-swell, special formulated buna-n. (Once
installed, there should be no reason to remove the adapter fittings).
Best Regards,

Gary Garcia
Manager
Product Engineering Group
Parker Hannifin Corporation
Racor Division"

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