limp mode??

darkside

New member
Sep 15, 2011
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left coast
I have had my truck for a week now and was passing a few semis yesterday. I romped on the go pedal and passed them, then let up on the pedal and romped on it again to blow out the soot;). when I romped down again it went into a kind of dead pedal mode and every time I would press down on the pedal it was like no go. If I held it down it would like down shift and still no go. It only went back to normal after I pulled over, shut it down, restarted it and it returned to normal. Anyone tell me what happened and how to avoid it?
 

darkside

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Sep 15, 2011
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left coast
Not sure what you mean. Cel. Sorry, I am new to the duramax and don't know too much about them.. I have had a cummins for many years and just switched over
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Not sure what you mean. Cel. Sorry, I am new to the duramax and don't know too much about them.. I have had a cummins for many years and just switched over

A CEL light is manditory on every US emissioned car from 97 on up. its the "check engine light". also known as the MIL, the light everyone covers with electrical tape, or hopes one day it will magically go away :D
 

darkside

New member
Sep 15, 2011
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left coast
Did not see check engine Lite.the only clue I had was when I would press and hold the pedal down it seemed to downshift and continued to have a dead pedal. I could slowly press on the fuel and it would gradually increase speed. but no torque.


Its because you "blew out the soot" :roflmao: Well actually No soot, it was a pretty clean burn.:)
 

BCata

BCata
Dec 14, 2010
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Boerne, Tx
my guess is that you have a limp due to low fuel rail pressure. You get this when you romp on the "go pedal" to demand excess amounts of fuel and the actual fuel supplied cannot keep up with the amount required.leaves you in a fuel limp until you clear the little orange code off your dash. you might want to hook up a reader to your truck and make sure. My guess is a 0087
 

darkside

New member
Sep 15, 2011
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left coast
I didn't see any cel. and saw no code.

It could have been limiting me to below 2000, not sure. It felt like less than that.
If I soft pedaled it I could get mild exceleration.

It has been maintained very well, It looks like new. I will change out the fuel filter.

I feel pretty ignorant because I know so little about the duramax. My cummins was pretty stupid very little computer control. Sorry if my questions sound dumb

What do can I do to maintain fuel rail preasure. Does Fass make a lift pump for these? What kind of gauges do you guys run.

I also note that I have 2 temp gauges- one reads about 150 the right side is around 180. Is that normal?
 

BlkMax

Member
Sep 1, 2008
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Wasilla, AK
This sort of sounds like when I lost the FPR on my first CP3. If I snuck up on the throttle, I could get the engine to carry some rpm, but if I stabbed it, the truck fell on its nose.

BTW, there were codes thrown, but I don't recall if I saw anything come up on the MIL.
 

darkside

New member
Sep 15, 2011
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left coast
sort of sounds like when I lost the FPR on my first CP3. If I snuck up on the throttle, I could get the engine to carry some rpm, but if I stabbed it, the truck fell on its nose.

BTW, there were codes thrown, but I don't recall if I saw anything come up on the MIL.

Yeah that is the way mine acted but when I shut is down and restarted, everything returned to normal. ( It healed itself. These maxs' are great):woott:

Does the codes show in the vehicle info center or do I have to do something to see the codes?
__________________
 

BlkMax

Member
Sep 1, 2008
743
4
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Wasilla, AK
Yeah that is the way mine acted but when I shut is down and restarted, everything returned to normal. ( It healed itself. These maxs' are great):woott:

Does the codes show in the vehicle info center or do I have to do something to see the codes?

You will need something to read the codes. Most here use EFILive or a Tech 2. You can also get a stealer to read your codes, for me it would cost $100 for 5 minutes for the technician.
 

JoshH

Daggum farm truck
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Feb 14, 2007
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Sounds like maybe you blew open the FPRV, but there should have been a CEL. Do you know if the truck has been tuned?