09 D8 goes into limp mode..wtf?

[ragincajun]

ok sled ran great all day and my idle started to drop and the gauges would come on when it got to around 1000 rpm. we were ridin around and the the check engine light came on and constantly flashed and went into limp mode. shut it off and started it and same thing happened. unpluged my fuel box to go back to stock and it ran great the rest of the day then on the way back to the truck it went into limp mode again and i shut it off and fired it up and it went away but the light would flash every once in a while..just a single flash. wtf is goin on??? fuel was dialed in and had 2 or 3 gallons of av gas just for safety messin with the fuel. anyone got an idea? voltage reg.? fuel filter? ecu? help! all stock except a slp can and the fuel box and egt's

 

[AndrettiDog]

Pay attention to how many times it flashes the engine light. That is key to what your problem is. I don't have the list handy, but there have been several threads explaining what the flashes refer to.

 

[DragonSlayer1]

box

What fuel box are you using??

Attitude gen 3.5 or dobeck style ??

 

[ragincajun]

i was looking for a pattern but it was a constant blinking. the other blinks on the trail were just a single or two at most flashes.

the fuel box was a dobeck gen 3.5

we did a compression test to see if it was det. but there was 90 and 90 on each side, whats stock compression? it also ran rich as hell after we unplugged the box and would only pull 7800 max with 59 gram weights. anyone got any ideas as to wtf is goin on? im new to poo so this efi stuff is all new to me

 

[francois]

I think one code would look like det and it can get on limp mode really quickly if it sees det. At least mine was doing that when my attitude box was not properly connected.

Compression with the update from last year is lower as we went from a 13:1 ish to 10:1 heads. However 90psi does look low to me.

I saw you are selling a set of twin pipes so i assume this is why you have a fuel controller, how are they? Saw any difference? Im selling my turbo kit because of money issue but Im having a hard time going back to stock!

Anyway Im posting this check engine list if it is of any help!

 

[DragonSlayer1]

Where is your ground connected for your fuel box?

 

[ragincajun]

on the left corner by your knee where everything is mounted to...and we double checked that it was in fact grounded because we had screwed up when we mounted it and discovered what we had grounded it to had a rubber isolator...and it ran for great for about 150 miles

 

[ragincajun]

found out we did compression test wrong and were suposed to hold the throttle open to get a true reading and was told as long as they were the same its good.

anyone got any ideas? its driving me nuts not knowing wth is wrong and there are no dealerships open on sunday so im goin nuts!!!!
HELLLP!!!

 

[sledx.net]

My 07 D7 did exact same thing. Didn't know what was happening late last day of trip. Got home and two other sleds started having issues. Turned out water in fuel, so det was my issue. I added two bottles of ISO when it happened but no help. I could shut it off, wait 1 min, then fire it up run WFO for few minutes and it would go limp again. Did that a few times to "limp" it back to end the trip.