Help with 7.4L tuning

[04hdstd]

Hello...
Let me introduce myself... My name is Ian

I am new to this forum and I have been reading alot of posts and learning alot. I am new to tuning GM's. I have used such standalone systems such as haltech and tec2 and 3.
Anyway I have already have a moates burner, the G2 adpater already installed and using tunerpro rt
Now for the vehicle, I came across a deal on a solid 88 GM truck that has a mild rebuilt 7.4L in it. The engine had a broken spark plug that i since fix. I have not driving this truck yet as I want to get the tuning setup on it. It has short headers and eldelbrock 2162 performer cam in it. I was told is had the ecm updated to the 7.4L chip. I did my research and found out that this isnt true. It still has the stock 5.7L chip in it. The ECM is a 1227747, the chip that was in it was the AMUU. I since flashed a PROM with the AKUP bin. Once I did that I started the engine and let it idled and warm up and it ran the same as with the AMUU except if I would rev the engine the knock count would go up alot. So i bypassed the ESC and got out the timing light and was shocked thinking I would see the timing around 10 degrees advance only to find it about 40. So i adjusted the timing back to 0. cleared the error codes and hooked up the ESC wire once again. The engine now seems to be correct timing and no more knocks. After the timing issue I took it around the block and few times and saw two things, first the ecm is in open loop all the time, second is the O2 is reading lean while driving. My question is what scalars or tables should I adjust to allow it to go into closed loop to see how far the BLM's are off. Also I know from dealing with other EFI systems and their VE tables would be a basic lower and upper fuel curve to get you in the ball park then go and and fine tune small cells that need some adjustment. I was wondering if that is possible in RT? Sorry if these are dumb questions I am still on a learning curve learning this software, I have been messing with some sample data logs I found on this site, and using the History tables and a spreadsheet I found here that allows you to input the BLMs and it will make the adjustments for the VE table.

Thank you for any help

Ian

[EagleMark]

AKUP is a Export chip/bin, it's Open Loop and I've tried to make it go CL...

Try ATPZ or ATPY. Then you will go CL and get some BLM numbers to work the VE table.

[04hdstd]

Thank You Eagle!

[04hdstd]

Hi Eagle, with the 7747 ecm, is there a way to datalog a wideband as the 7730?

[EagleMark]

Never have figured a way to do WB in same log...

I use Innovate data logger and IIRC you can combine that data log and a TunerPro Data log and use it in Excel...

[04hdstd]

thanks... i will take a look into it... I seen a thread where you and a few others were talking about it and the only real idea was using a voltage divider on factory NB input

[04hdstd]

Hi Eagle,

Can I ask a few questions???
I know BLM and INT are some what related, but im not quite understanding it. Correct me if im wrong but I understand BLM to be a measure of how lean or rich the engine is running and used that data to trim fuel. Int i thought was very similar but in the DL's i see the two on the graph sometimes mirror one another than other times they seem to be mirroring one another but in different directions. for example BLM could be 124 while INT is 133.

On Tuner Pro, the Stoich Afr scaler, I take it if i move that setpoint it will try to control the engine at what ever you set, and how much power or how much error correction does the 02 senor have?

Thank You

[Dr.Danger]

AKUP is a Export chip/bin, it's Open Loop and I've tried to make it go CL...

Try ATPZ or ATPY. Then you will go CL and get some BLM numbers to work the VE table.

Thread resurrection.

Mark, can you expand on this a little bit? I just found this post after scratching my head for a few days trying to get the AKUP bin to go into closed loop on my Ford big block.

I thought it was my unheated 02 sensor, which was pretty old anyhow so I replaced it with a 3 wire and got between 880-920 mv at idle, but it never did go into closed loop after fully heating up.

Thanks,
Dave

[Six_Shooter]

Most export bins are set to be open loop all the time, since many places still use leaded fuel that destroys O2 sensors.

Though I haven't used the specific bin cited here, it seems that simple adjustments of certain scalers that should make it go closed loop don't seem to be effective, so the best option is to start with a bin that will go closed loop.

[Dr.Danger]

Most export bins are set to be open loop all the time, since many places still use leaded fuel that destroys O2 sensors.

Though I haven't used the specific bin cited here, it seems that simple adjustments of certain scalers that should make it go closed loop don't seem to be effective, so the best option is to start with a bin that will go closed loop.

Thanks, I'll try one of the recommended bins above and start fresh in the morning.

[04hdstd]

Thanks, I'll try one of the recommended bins above and start fresh in the morning.

Hey Doc, I used the ATPZ, basically the same as far as I could see as the AKUP except it goes into CL

Ian

[Dr.Danger]

Hey Doc, I used the ATPZ, basically the same as far as I could see as the AKUP except it goes into CL

Ian

Thanks for the info. I'm going to try the ATPY first because I've got large tires and 3.54 gears, so we'll confirm if that one works out as well. If it doesn't I'll switch over to the ATPZ.

[mmigacz]

thanks... i will take a look into it... I seen a thread where you and a few others were talking about it and the only real idea was using a voltage divider on factory NB input

I made a voltage divider and tried this. The datalog only read 13.9 AFR (approximately .443 volts), no matter what how much the AFR on the controller varied. Its like the ECM was ignoring the voltage input and used .443 volts for everything. Maybe it has something to do with forcing the ECM into open loop.

I didn't get a lot of time to mess with it. Maybe today I'll go out and play with it.

[Dr.Danger]

Loaded up the Ostrich with the ATPY and all was well, except for one thing. Evidently this bin uses an open loop at idle regardless....

Off to search and figure out how to change that. At least now I can get started with everything else.

[Six_Shooter]

Most people find they prefer open loop idle, especially when it comes to using the '7747.