2 more years gone by... Still surging on Cruise

[SixOhh]

the old thread was closed for some reason..... but the problem still exists.

http://competitiondiesel.com/forums/...=115135&page=2


I have logs of it anyone want to see it on EFI live. Since that last post i have been thru 2 transmissions, went from compounds to a single, new VSS, CSP-5 with stock tunes and different OS's to switch from while the problem is occurring AND i have even rebuilt the motor from the ground up (for different reasons of course)

the only thing that still remains the same is it only does it on cruise...... NEVER without it on. the only other problem my truck has consistently had is p0341 disabled because my crank sensor refuses to work. could these 2 problems have anything to do with each other?>?

Does anyone REALLY know what is being done when on cruise control and not anywhere else? is it just PCM calculations on VSS and engine load and such?

the only thing i haven't changed is the PCM/ECU and my MAP sensor. EFI live shows map to be fine.

just bringing this up again to see if anyone has learned anything new. im not the only one suffering here. plenty of other trucks doing it.

-Marcus

[wildman6bt]

My 03 did it last summer driving interstate to work so I quit running cruise. It's not as violent this year but still does it on hills. I got 20% over "50hp" Exergy, he351 ported wastegate, and Afe intake on stock tuning. Seems to be a common problem yet everybody is like "yeah it's normal"

[Red Sleeper]

For the past two years, has your crank sensor not functioned? In other words, when the crank sensor stopped functioning properly did the problem surface?

If that's the one thing you haven't tried or replaced, why wouldn't you fix it? Just to eliminate that sensor being tied to the surging problem....

[dangerous06]

It's usually in the tune that does that.

[dieselbeef]

vacuum issue..neck it down so it responds slower

[Scooter's Roofing]

Originally Posted by dieselbeef

vacuum issue..neck it down so it responds slower

his truck is drive by wire

[dieselbeef]

it doesn't use the same but diff setup as the 02 then? its completely by wire..electronic cruise

[Red Sleeper]

Yes. Wires everywhere.

[SixOhh]

Originally Posted by wildman6bt

My 03 did it last summer driving interstate to work so I quit running cruise. It's not as violent this year but still does it on hills. I got 20% over "50hp" Exergy, he351 ported wastegate, and Afe intake on stock tuning. Seems to be a common problem yet everybody is like "yeah it's normal"

yeah that drives me nuts as well. just because its commonly occurring does not make it OK to me. it didnt do it when it was new and some days are better than others but cruise control is a must for me.

i WILL figure out this problem one day

[SixOhh]

Originally Posted by dangerous06

It's usually in the tune that does that.

that's what les said as well. we have been over it time and time again. i recently installed the csp-5 and installed my stock file, 3 street tunes and a single event tune. they all surge.

les tells me its a drastic cell change in my main inj. pulse table. i have made 3 different pulse changes in a row and sent them to my tune with no luck. all of my cells differ no more than 150 in that area. could it also be in the pedal position offset in EFI?

i am even considering going as far as putting stock size tires on the truck to see if it goes away. that would tell me that its related to VSS/tipm. (the only thing i cant change with EFI )

has anyone ever beat this thing????????/

getting down to the heart of the matter..... it has NEVER EVER done it to me while im on the pedal, only on cruise. Isnt that an internal calculation on the ECU that goes off engine load and VSS? no one seems to be able to answer this. and i am sure this is a calculation that cannot be altered.

i might even spend the day on my Tune Tool in EFi and try 5 different variations of my street tune altering pedal position and such and see if i can find a combination that makes it go away.
Once that is achieved i can make that a "cruise control tune" for my CSP.

all this work and headache for such a simple task.... NORMAL CRUISE CONTROL

[kamdsl]

Mine did it to me when I first started messing with efi. It would do it on a slight downhill, worse with a trailer where it only needed a tiny bit of throttle to keep speed. I got rid of it on mine by re scaling the pulse tables to an even increase and then making the pulse duration climb at the same rate to match. Also made the mm3 climb at a slower rate to make a finer fuelling in the low fuel area. Worked perfect for me, not sure if you have tried that or not yet...

[SixOhh]

i understand what you mean on the Main Injection Pulse Smoothing. i have tried that in several ways. but i dont think i follow you on making the duration climb at the same rate.

[kamdsl]

Basically, I just use simple math to make the table and have had great results from doing it.

Pulse mm3 is re scaled to climb at an even rate from 0mm3 up to say 50mm3.
Then pulse us is calculated to climb at the same even rate to match the mm3 commanded.
In mine I also went to the extent of making the small mm3 (0 to 50) take up more of the table as that is where I spend most if my time driving = better manners.

Clear as mud?

[shane.f]

I have the same issue with 2 different tuners.... One says its the tune one says its hard parts......Hope you get it hammered out so I can piggy back your results

[Dtruck1]

Originally Posted by dieselbeef

it doesn't use the same but diff setup as the 02 then? its completely by wire..electronic cruise

03-current don't have vacuum pumps.

Have you tried swapping FCAs? I had a modified FCA at one time that would surge real bad when the ambient temp got around 40 degrees. I swapped the FCA and the surging went away.

[phale]

Does it do it with a completely stock duration table?

[SixOhh]

I am pleased to report it is GONE. ... i have said that before but i have done what Matt suggested above and it worked!

i smoothed out the mm3 a while back under Les' watchful eye but it still wasn't gone.. better but not gone. after i rescaled the axis table it finally made sense... give it more "room" in the cruising area.... way less transition from cell to cell and nice even numbers for the ECU to calculate.

i have a 7 hour drive home from west texas thru the hill country to houston so if it will do it all all i will find it tomorrow. i have 3 different tunes loaded on csp5 with slightly different main injection pulses. ill log them and find the smoothest one on the rail and it will be my new favorite street tune!