VDH2+TNAA4

[907DAVE]

I am having some issues with the programs provided with the Definition file. All the programs make the truck buck and jerk while cruising/ lightly accelerating at slower speeds. They seem to smooth out after the truck completely warms up. If you accelerate moderately there is no issues, otherwise they work well. Ohh and the "stock" file will not do it.

Anyone experience similar issues?

Thanks

P.S. Another symptom might be some dead spots/ delay in the APP, but hard to tell as I was not driving.

[cleatus12r]

I'll email you a file to try, Dave. I know it works and if it doesn't work on the truck you're speaking of, then there is another problem.

[907DAVE]

Damn.....thanks!

I will give it a shot, still curious what could be causing this.

[907DAVE]

Well truck is still acting up....... even with the file you sent me Cody.

Still bucking at light throttle/ cruise conditions in ALL the programs except stock only when the engine is cold, warm it up a bit and it will completely go away.

Any ideas?:help:

[cleatus12r]

Sounds like some kind of HPO issue to me, Dave.

[907DAVE]

But why does it NOT have any issues in the "stock" file?

The ICP, IPR% in the programs are almost identical to stock in the low rpm/ cruise ranges.

[907DAVE]

I might have forgot to mention that if you accelerate moderate to heavy it wont act up a bit. I would think an ICP issue would be aggravated by hard acceleration.

[907DAVE]

Well got some testing done tonight and it is an ICP issue.

Funny thing is that it is commanding the IPR to drop pressure, then back up again repeatedly.

I graphed (Genesis) the IPR %, ICP, APP, and PW. When the problem occurred the IPR% and ICP would drop simultaneously, spike back up, drop, and so on. When oil temps climb both would increase and decrease smoothly, and the problem slowly faded away.

There was no spike up in ICP to cause the IPR to drop, both would fall at the same time. All the time the APP would hold constant, so rules that out.

Truck ran perfect before and perfect with a Superchip programmer.

Is there a possibility there is an issue with the Definition files?

Any ideas?

[cleatus12r]

Do the maps look ok when you open them in Minotaur? The tunes that Bill sent you when you got that TNAA4 definition are the same tunes that he has on the FU server that a whole ton of people are using....without these issues.

In all actuality, if it does this while running the tune I sent you then something is wrong with the truck for sure. That tune has been and is running fine in another truck....and it's been in there for better than a year without those problems.

I have been thinking a lot about what is going on but I am out of ideas. I knew it would be a HPO issue of some sort but the strange thing is "why". Especially since it only started doing it after Bill's tuning was installed.

So is the Superchips still available? You say that it doesn't do it stock.......

Can you copy and paste a stock IPR map and a stock ICP map into any of the programs and try it from there?

[907DAVE]

Do the maps look ok when you open them in Minotaur?

Yep, everything seems ok.

So is the Superchips still available? You say that it doesn't do it stock.......

I think he might still have it. Nope, smooth in stock.

Can you copy and paste a stock IPR map and a stock ICP map into any of the programs and try it from there?

That was the only idea I had left.

How much of an effect will this have on performance?

What else can cause a drop in ICP, MAP?

[cleatus12r]

That was the only idea I had left.

How much of an effect will this have on performance?

What else can cause a drop in ICP, MAP?

The performance won't drop very much...and you certainly probably won't even notice :D .

I suppose if the load calculation is off.....but that's usually calculated by exhaust backpressure.

[907DAVE]

Thanks Cody, I have a couple of programs burned to a chip for him to try. Should know within the week whether its works or not.

[907DAVE]

After using some stockish ICP and IPR% maps the problem is resolved.

Still a very curious issue, to me.:)