I have a head scratcher. Whenever I fill up, truck is low on power for the next 20-30 minutes. The truck will usually die, ONE TIME, the first time you let off to stop. This can be one mile down the road or twenty miles. Cranks right back and won't die again. We have tried not topping off the tank, leaving cap off, and fueling at different tank levels. Lift pump is new. Truck runs fine with full power after 20-30 miles. Power comes back gradually, it's not like flipping a switch. Engine temp doesn't matter.

Thanks

Welcome to M1973M.

 

Fill in your signature and let us know what you have for a ride and a detailed description of it and any current or past modifications repairs or added options ect, anything to help out a bit better.

Signature complete.

The 2003 belongs to my business partner and I am not very familiar with the CR. The truck has an Edge programmer under the hood, not sure on model, but it does not have selectable levels. Truck is basically stock. It does have MBRP exhaust. Bought second hand, so unsure if it had other mods.

Edited December 18, 201410 yr by QDM4fun

My first thoughts are to eliminate the edge. I have seen them do crazy things when they go bad. Ill do some thinking because this is a weird one

I just can't figure out what filling the truck up with fuel could affect. We have tried fueling while the truck is running and turning it off to fuel. The only thing I can come up with is maybe the fueling is somehow getting air in the fuel system? There is no "fuel sensor", like in a flex fuel vehicle, correct? I feel like it has to be a mechanical or physical problem, not electrical. He did say if he gets fuel at about 1/4 tank and fills to 3/4, he has no problem.

little confused here.   is it  the  2001  or 2003..     those are not   CR's.

 

Are you getting fuel  from the  same  place  everytime  this  happens,   or  is it  no matter where you buy it?    

 

The  truck with the new   in-tank LP..   this is  the one you are talking about right?    Isspro  gauges;   you have   fuel pressure  correct?     what's pressure doing when it's  acting up?

 

was the LP  changed out to  fix THIS  problem... and  didn't  fix it?

This problem is on my business partner's 2003 CR, not one of mine. He has no gauges. He said he has LP under hood mounted on firewall. LP was not replaced to fix this problem. Assuming it is fuel pressure related, why would he only have problem when tank is full?

2003 are common rail and fuel is measured in flow not pressure. I cant think why fueling up would cause it to die. Unless the cold fuel is seizing up the warm fuel pump or something.

Uh he shouldnt have a pump in the firewall. It will be mounted on the back of the fuel filter or if its been modded with a chrysler pump it will be in the tank. Or it could be on the frame near the tank

Edited December 18, 201410 yr by mopartechnician

His pump is probably on filter canister. I thought it would be in the tank, but he said it was under the hood. Like I said earlier, I am not familiar with CR.

That's a weird issue for sure.

 

My first guess is that the fuel level is somehow blocking the vent in the tank and it creating a vacuum which reduces flow.

I thought that also, so we tried leaving the fuel cap off. Is there a simple way to test fuel flow?

This is messy but... You could loosen the fuel filter lid and taking a rag and a air gun and blowing some pressure to the fuel tank to verify the fuel can flow to the filter and there is no blockage. As for flow you could open a fuel line up and route into a bucket or similar and turn the key on and see what comes out for flow. Another way is to measure fuel pressure at key on and the continue to watch as you start if the pressure falls out then the lift pump supply volume can't keep up with the demand volume hence a fall in pressure.

 

There is always more ways to skin a cat...

This problem is on my business partner's 2003 CR, not one of mine. He has no gauges. He said he has LP under hood mounted on firewall. LP was not replaced to fix this problem. Assuming it is fuel pressure related, why would he only have problem when tank is full?

Gotcha!

 

ok,  how about this:    something is  goofy  with the  return going back to the  module,   ... and  when the tank is packed full,   the return is  compromised...  thus  'jacking'  with the   internal pressures  of  the  cp3???    After  20 miles or so,   enough  fuel has  left the tank   things  resume to normal...

 

Makes me wonder If the return line is  on the right nipple..

Edited December 18, 201410 yr by rancherman

I had a "sort of" similar issue on my way home from North Dakota in October.  My truck never died, and it ran fine the whole time and rail pressure was normal.  The weird thing was the way my Autometer lift pump gauge was acting. I described it here in this post.....................................

 

 

I had a VERY WIERD experience driving home from NoDak yesterday with my electronic Autometer FP gauge after getting back on the highway after a fuel up.

 

Pulled into the station, did everything I normally do when filling up.......................dump my 2 stroke oil in the tank, then swipe my card, wait for the card verification, grab the diesel line, pull my 2 stroke container out and insert diesel line and then dispense fuel.  However;  this pump sounded very odd.....................very AIRY sounding.  Anyhow, the pump clicked off, and I go to top off.................it wouldn't let me top off.  OK, I call it good, and we hit the road again.

 

After we hit the road, the fuel gauge is reading about 3psi lower than normal and is bobbing anywhere from 3psi above normal to 6-8psi below.  It acted this way for probably 50-60 miles before it settled to it's "normal" spot.  I really think I got a bunch of AIR in my diesel at that fill up and as the bubbles went thru the Walbro FP it was causing the huge fluctuations I was seeing.  My truck drove fine, and I couldn't "feel" anything in the way the truck drove while the gauge needle was dancing up and down.  My gauge is next in line after the pump................then my 2 filters..............then the CP3.  

 

 

That's the only thing I can attribute this to.  What y'all think???

That is strange and how they measure proper amount of fuel you pay for with the air mixed in ?

Edited December 19, 201410 yr by JAG1

That is strange and how they measure proper amount of fuel you pay for with the air mixed in ?

 

Did you know  diesel fuel is   'sticky' enough to  keep a   meter  unit  turning?

a  couple years ago,   I pulled into a   road side  convenience  store,  to fill my tractor.   They had  the off road  fuel   out back,  in  above ground tank.

Put the  hose  in  and  let her rip.     should've  been  about 60 gallons  to fill  my tractor,  but   kept on  chugging... and chugging,    I   shut it off at  50,  and  I  didn't gain  a  bit  in the tractor.    It only    sent  foamy air to the  tank.     Thank goodness the   owner was there  and  agreed  I didn't  put   50 gallons  in the tractor  (my gauge was  still reading  empty)  His  supply tank  was  dry.

 

So,  yeah.     pumping  air  is   apparently  not so  difficult to   'measure'!   

Yep, I wonder about this when I see the fuel comes out like foam at the pump.

When I fill up, I always click it to the slowest fill possible.  Seems to sound less airy that way.

talk about the stars aligning today on this  subject!

Filling the tractor today out of my  above ground  tank, and     apparently  my  tank filter is   almost plugged.     and   the froth  coming out   'looked' full stream,   but  it  took almost 20 minutes  to fill 55 gallons!

 

I guess  when  the  suction  gets too  much,  it's  drawing  air  'somewhere'.      hmmm.        It's  a  jive old    'Fil-rite'   typical   farm  fuel pump.    I draw out the bottom of the  tank, through a  spin on filter,  then through the  pump itself.

(tank filter is  now  sitting in the house.. warming up)...

The pumps can cavitate with too much suction pressure and make air bubbles.

The pumps can cavitate with too much suction pressure and make air bubbles.

Yep. It literally pulls the fuel apart and causes the air problem.