I have had 3 people attempt to tune my setup, and every single time I have different issues. I am running and driving, but am constantly having issues. I have even gone as far as to get the HP Tuners myself and try to do basic stuff to try and improve it, but everything seems like 1 step forward and like 10 steps back. I don't know what the deal is, but I am seriously at my wits end with it and am losing hope. Is there anyone that is near Seattle/Tacoma area that knows WTF they are doing that can help me!? I can bring the vehicle and my laptop and software I just need help. I am about to throw in the towel and part out the project.

 

Lets start with describing the problem...

 

Cold starts now for some reason 90% of the time it will start and then immediately begin to surge and try to run lower than the idle speed that is set. runs about 500 rpm but will surge. Also when this happens the throttle pedal is dead. It is a DBW and all of the connections are good and components are working. I shut it off and restart and will be fine. every day this becomes a more frequent occurrence. It used to be once in a great while when the problem started,, but lately is almost every time.

Secondly when I am driving and past the cold start issue if I coast the idle surges also, but as soon as you slightly give it any throttle pressure it stabilizes. It will sometimes also do this while you are sitting stopped say at a red light with your foot on the brake in gear.

When you accelerate and it goes into positive pressure say anything above 2 psi you can feel it fall back a bit like it actually loses power. The more gas you give it the worse it gets. The AFR is rich but you would swear it was acting as if it were going lean and pulling timing out. This is not just during WOT, you could be at about 50% and still will react the same way.

I haven't changed anything on the tune other than the idle speed. It was set very high before I touched anything (1100 rpm). I set it to go from 850 and drop progressively to 675 at it's lowest. This is on the table that goes by rpm vs temp in the idle tab.

I am only running the stock 3.7 pulley on the blower and am making like 7-8 psi at WOT. I hope this helps, but i think that it will take someone poking around in the tune to see wtf might be going on. I know that i don't know enough to fix all of this and really would like to get it to someone who does so it can just get corrected.

 

The first problem sounds like a fuel issue...either a dying pump or wrong injector data, same with the third problem. Second one sounds like the base running airflow table needs tweaking. The third one could also be spark related.

There are a lot of good tuners on this board, so if you post up with a complete list of your mods and attach a copy of your tune (.hpt) file and log (.hpl) of driving around, you will probably get most of it tightened up.

 

Do you have a wideband?

 

I have a copy of the tune file now, but i don't have a log. Hell, I don't even know how to create one. I will be more than willing to do that just need to know how. Is there something on the software help that can tell me how? Also i know that the pump isn't dying out. I have an electric fuel pressure gauge in the cab. Fuel pressure is set at 60 psii and it stays there or up to 62 when under boost. I was always nervous about going lean and do pay a lot of attention to that.

 

No, unfortunately I don't, I know i should get one, but just haven't had the chance to yet. However it was tuned with one the last time i had it to someone.

 

Also I guess the other question is when i start scanning and create a log while driving around, how long shout it be? How long should i drive with it?

 

If you cant figure it out take it to Tom @ Wong engineering in Vancouver WA. Really knowledgeable in Ls stuff, works mainly corvettes. He is the only one I trust with my projects for tuning or installation.

 

any update?

just go drive around normal, roll in to it slow, try a WOT run..
but without a wideband, its gonna be harder to figure out whats goin on.

How about the mod list?
Tune?