T42/E38 Tune or Repair?

[avy]

Hello.

I just did a DOD delete with 228/230, 585"/.585" 112 LSA. Engine runs smooth now thanks to another member on here.

I still have the stock trans internal (4L70e).

My truck maintains speed by itself or gets up to speed without throttle. Do I need to get a better stall converter? Or will a tune help?

Thanks in advance!

[RDF1]

That cam with a stock torque converter isnt the best setup.
The engine needs a certain amount of air to be able to idle decent and if the torque coverter is too tight your going to be pressing on the brake more to hold the truck still.
Going with a 3200-3600 converter would make it much more responsive and drive much better.

[avy]

Great. I will get a new converter. Any tuning needed after I install it?

[Alvin]

What is the idle speed? Usually that and too much BRAF is the cause for this.

This is borderline. It should get along with the stock converter but it's going to be close. It should be limited to pulling a little bit at a stop.

[edcmat-l1]

My opinion, 3200 rpm is too much stall for most street applications. While it may need more stall it would probably behave better with considerably less.

Also, it would be much better to see the tune file and a data log of it running to determine if it can't be helped with tuning. Based on the OPs other thread chances are it needs some help.

It's possible it needs the BRAF reduced. It's also possible it's getting additional air from somewhere and the only way to know the answer to both those questions is to see the tune file and a data log of it running.

[avy]

Here is a test drive I completed for another member to help tune the ECU. That thread is https://forum.hptuners.com/showthrea...une-Assistance

I can do a log. Please let me know if I need to add any channels.

[edcmat-l1]

Looks like you have other more important issues. It looks like it's missing on bank 1 and bank 2 O2 looks real strange.

[avy]

There was a tune file edited after that was posted. I will do another log with the current tune and post it here. Any channels to add for the transmission?

[Alvin]

My opinion, 3200 rpm is too much stall for most street applications. .

especially for a truck. Rather have the stock stall in a truck and if the cam won't get along with that.. usually means the cam wasn't picked right. I wish more people would let me spec builds. I drive so much.. I can tell you exactly what feels soggy and what feels great.. What pulls all over good.. what doesn't.

I'm sure you could too Ed.

We get so much seat time in all these different builds.

[Alvin]

There was a tune file edited after that was posted. I will do another log with the current tune and post it here. Any channels to add for the transmission?

Looking at this file.

The VVE is in rough shape.
There is very minimal tuning overall.

But there shouldn't be a feeling of cruise control with this.. This cam should have needed a good bit more air added to the idle. This file shows no more air than stock. That tells me air is getting in somehow.. likely from a vacuum leak. I'd smoke test this. Truck intake gaskets seem to be bad about leaking or it could be a PCV line cracked or off somewhere.

[avy]

Finally, got the truck smoke tested. Everything is great. I wonder if I need to just start over with the stock file.