Diesel Place banner

1 - 20 of 25 Posts

·
Registered
Joined
·
402 Posts
Discussion Starter #1
Ok guys one thing I keep expirencing, seems to be hit and miss, not really any correlation between tunes or anything, sometimes I will flash a new tune, the truck will run fine, but then while driving normally I will go to grab more pedal and it feels like the motor goes into limp or something, to where only the first 25% of pedal movement has an effect on the motor, if I put it to the floor the truck will just slow down even further, downshift, and have no power until I back off to like 20% throttle, no DTC's either, if I stop, flash a different tune, then it wont do it again. WTF? any ideas? Like I said it doesnt seem to matter what tune it is it just like hit or miss. wierd.

Thanks,
Justin
 

·
Registered
Joined
·
2,213 Posts
changed your fuel filter or checked the water trap recently?
 

·
Registered
Joined
·
2,194 Posts
I would say.......EFI LIVE. The engine will not act like "That" w/just a plugged filter.
 

·
Registered
Joined
·
1,580 Posts
yes but what would cause it with efilive I have experienced this a few times as well? any tables to adjust to fix this? good question.
 

·
Registered
Joined
·
2,213 Posts
I think if it was a programing problem, it would be consistent. keep watching for any correlation with engine temp, intake temp and pressure, ambient temp, anything you can think of. I have had some screwy things happen with plugged and/or leaky fuel filters though... Also, check your timing in your tunes...kinda sounds like it may be too far advanced at higher TPS, and bursting.
 

·
Registered
Joined
·
2,012 Posts
03LB-7dmax;1594149; said:
I would say.......EFI LIVE. The engine will not act like "That" w/just a plugged filter.
I would say run it with the PPE Xcellerator for a few days, that will help to narrow it down ;)

It might help to decide if it's tune related, HP related, or something else...
 

·
Registered
Joined
·
402 Posts
Discussion Starter #7
fuel filter was just changed about 100 miles ago. What exactly do you mean by "bursting"? Its strange because some times it will do it right after starting and warming up the truck, or just starting up if its already warm, putting it into drive, (say im pulling out of a parking lot) get on the road to get up to high way speeds, and after about 25-30% throttle, bam, nothing more, you have to almost feather the throttle to keep going. Other times it will be running fine, crusing on the interstate, pull off, stop at a stoplight, go again and then at about and above 25-30% throttle again nothing, sometimes turning the truck off and starting it again cures it, other times 1-3 start ups its fine. thanks guys
 

·
Registered
Joined
·
5,839 Posts
Why not return it to stock for a few days...if it does it while it is stock take it to the dealer..
 

·
Registered
Joined
·
2,172 Posts
sounds like the efi is harder to understand than the lb7 or lly, or is this not the matter..... not much luck comming from the efi camp.. hope to see this change
 

·
Registered
Joined
·
1,366 Posts
Have you logged the truck when this occurs, and compared desired values to actual? ie: Rail pressure, MAF, Boost, etc.
Are you checking for DTC's while it is occuring?
Does this occur with a stock tune?
Are these your own tunes or someone elses?
Did you or someone else manipulate DTC reporting?
Have you compared the tunes in question to your stocker?
 

·
Registered
Joined
·
2,012 Posts
fredw;1594533; said:
sounds like the efi is harder to understand than the lb7 or lly, or is this not the matter..... not much luck comming from the efi camp.. hope to see this change
Great diagnosis...

LBZ GMC-As suggested, try the stock or PPE tune, or do some logging to help eliminate possibilities...How old is the lift pump, could it be going South?...Is it a flow-through setup that will allow the CP3 to pull through it if it fails?...
 

·
Registered
Joined
·
402 Posts
Discussion Starter #12
yeah it is a flow through pump, I do have a log of this occuring, how do I post it up for you guys to see?
 

·
Registered
Joined
·
209 Posts
mine has done the same thing since i started using the dsp2. when i load the 'same' tune in the non-dsp2 version it runs like a scalded ape. when loaded with the dsp2 os, the same thing. limit to 2000 rpm, when the truck idles for extended periods of time or on start up pops turbo overboost codes. i was hoping someone else was having this problem.
 

·
Registered
Joined
·
1,474 Posts
LBZ_GMC;1595440; said:
yeah it is a flow through pump, I do have a log of this occuring, how do I post it up for you guys to see?
Email it to support (at) efilive (dot) com , it will end up in the right hands.
I think the thing to track down exactly what you are chaning to cause the issue is to at least put the stock tune back in, see if the problem comes back, if not, then review the changes you have been making can try changing one thing at a time or in smaller steps, that should help track down what is happening.
It seems rather odd that it would go in to limp mode (by the sound of it) and not set a DTC.

Rushingbc, did you set the tune up yourself?, sounds like you don't have some tables in the DSP2 section configured correctly.

FredW, helpful as always when it comes to EFIlive :rolleyes:

Cheers,
Ross
 

·
Registered
Joined
·
88 Posts
y truck doing the same thing.truck runs fine with efi tune installed,put the truck back to stock,runs fine till shifts to fourth gear and acts like its going in limp mode,ease off throttle,fine,ease back down and same thing.put tune back in fine,no problem.any suggestions.
 

·
Registered
Joined
·
209 Posts
Ross, I havent had a chance to go back in and see where i screwed it up, but i kinda figured the same thing. hopefully i'll report that my attention to detail isn't what it used to be :rolleyes:
 

·
Registered
Joined
·
4,123 Posts
LBZ_GMC;1594068; said:
WTF? any ideas? Like I said it doesnt seem to matter what tune it is it just like hit or miss. wierd.

Thanks,
Justin
Do you have a EGR fooler on? If so pull it and see if it still happens :D
 

·
Registered
Joined
·
402 Posts
Discussion Starter #18
Kat, I do have a fingerstick installed, and its always been in the back of my head that maybe it could be causing this.....I will try and see what happens, Thanks! Flashscan, I seem to have lost the log somewhere (my DA mistake) I wil try to make another one if it does it again, I am going to try removing the fingerstick and see what happens as well.
 

·
Registered
Joined
·
3,557 Posts
I'm running a tune right now that only does it for the first 5 min. or so. Maybe some thing with coolant temps. I haven't had the time to look into that.

code 299 is on, but diffenetly in limp when first drive it, but limp goes away a short while later, while the mil light stays on while in limp and not.
 

·
Registered
Joined
·
4,123 Posts
IdahoRob;1598199; said:
code 299 is on, but diffenetly in limp when first drive it, but limp goes away a short while later, while the mil light stays on while in limp and not.
I think what he is describing is different then the 299. I have had gotten those on a couple of early tunes Pat did for me.
 
1 - 20 of 25 Posts
Top