Starting to Learn on 95 G30 5.7 for Towing

**donf** · 01-11-2019

Thanks for the advice! I think the problem may be in the ADX file, it's the one with the crazy spark readings and the logging problem. There are a lot of things turned off from the factory on the G30 bin like the cat overheat. I returned the altitude table to factory. but left the scalar turned off for now. The Ignition module is a Borg Warner not OEM. If next weekend is good weather I may drag the dyno out and see if the dyno can read the changes. When switching a few things off and on, if it's really altering the timing that much, there should be a change in turning off the scalar. I want to try to figure out why this is acting the way it is so it doesn't all of a sudden add 15 degrees more timing for some reason when the table is adjusted for some mystery defect. I think I may just switch logging over to the ALDL Scan Program. It seems a little more stable, timing wise. John the programmer thought the funny numbers may have something to do with signed data. He has been a great help! The bin started with the factory bin with the transmission shift and vss tables lifted from a BYJM with its lower gear ratio. Its changed from there but I try not to change stuff for no good reason. Like the PE. It looks bad on the chip, but whatever they do its a millisecond until it hits 12.5 AFR at WOT, not 15 seconds like tuner pro says. I figured eventually, once it's a little more dialed in, I will leave it at WOT for an extended period to see if it goes crazy rich once that kicks in.

**Fast355** · 01-11-2019

Originally Posted by donf

Thanks for the advice! I think the problem may be in the ADX file, it's the one with the crazy spark readings and the logging problem. There are a lot of things turned off from the factory on the G30 bin like the cat overheat. I returned the altitude table to factory. but left the scalar turned off for now. The Ignition module is a Borg Warner not OEM. If next weekend is good weather I may drag the dyno out and see if the dyno can read the changes. When switching a few things off and on, if it's really altering the timing that much, there should be a change in turning off the scalar. I want to try to figure out why this is acting the way it is so it doesn't all of a sudden add 15 degrees more timing for some reason when the table is adjusted for some mystery defect. I think I may just switch logging over to the ALDL Scan Program. It seems a little more stable, timing wise. John the programmer thought the funny numbers may have something to do with signed data. He has been a great help! The bin started with the factory bin with the transmission shift and vss tables lifted from a BYJM with its lower gear ratio. Its changed from there but I try not to change stuff for no good reason. Like the PE. It looks bad on the chip, but whatever they do its a millisecond until it hits 12.5 AFR at WOT, not 15 seconds like tuner pro says. I figured eventually, once it's a little more dialed in, I will leave it at WOT for an extended period to see if it goes crazy rich once that kicks in.

I might be able to explain the PE a little better. Basically there are two different entry methods for PE. One is at a much lower throttle opening and delayed by time or rpm. The second (Fast Entry PE) happens as soon as you cross over the TPS value. The first PE entry also uses a delayed air/fuel ratio decay. It is possible on the G30 since it was not as heavily regulated on the emissions that the first step of PE was eliminated all together and you only have the fast entry. Fast Entry PE TPS table would be set the same as the PE Entry TPS table.

**donf** · 01-12-2019

Thank you for the help. I will mess around with it this weekend and see if anything else adds up. It really runs well as is for a big old van, I am just hoping for a little more. Looking at my bin today I did see where the altitude correction table is still 0. I keep copying and pasting,then forgetting to click in another cell so tunepro will save it. So that was 0 in the last test. I am not sure it mattered since the scalar set to 0 too disabled it.

**donf** · 01-13-2019

So the first full WOT dyno run was not aborted only because I was looking at tunerpro to see when PE and AE where kicking in instead of the dyno screen. I slowed the acceleration rate down to better simulate towing and it went very lean for the first second and a half. Not lean enough to make a drivability problem but lean enough to where I don't want to repeat that mistake. I think I need to work on the AE. The rest of the run hovered around 13 so that's not bad for now. So some nice person here posted a Bin that is supposed to be from a 1996 G van HD with vortec heads. I opened the bin up it looks to be very minor changes in some of the AE tables. Here are the two most changed tables and one is only changed when its very cold. So my question is does this look like enough of a change or may I need something more. It looks like the tables affected have to do with time, but what table affects the amount of fuel? I am not fully understanding these yet. I was surprised but a lot of the AE tables where exactly the same for the 96 vortec head tbi van vs my 95. The hp and torque on the first run were improved over the tbi heads and flat tappet cam through the whole range but I think there is still some timing problem holding it back by a lot.

Edit: I think the time in the AE tables is adding time to injector pulse width. If that is the case, then the 96 tbi G van looks to lean the TPS AE table at the very top not increase it compared to 1995 and the 193 heads. It's not bad drivability wise as is at all, but I would rather not be that lean even for a second. There is a lot of talk about AE here in past threads, but not many specifics, also the older tbi computers appear to have a fewer tables. I think I will test the theory by increasing the time slightly in the two main tables and see what the result is.

**Fast355** · 01-13-2019

Originally Posted by donf

So the first full WOT dyno run was not aborted only because I was looking at tunerpro to see when PE and AE where kicking in instead of the dyno screen. I slowed the acceleration rate down to better simulate towing and it went very lean for the first second and a half. Not lean enough to make a drivability problem but lean enough to where I don't want to repeat that mistake. I think I need to work on the AE. The rest of the run hovered around 13 so that's not bad for now. So some nice person here posted a Bin that is supposed to be from a 1996 G van HD with vortec heads. I opened the bin up it looks to be very minor changes in some of the AE tables. Here are the two most changed tables and one is only changed when its very cold. So my question is does this look like enough of a change or may I need something more. It looks like the tables affected have to do with time, but what table affects the amount of fuel? I am not fully understanding these yet. I was surprised but a lot of the AE tables where exactly the same for the 96 vortec head tbi van vs my 95. The hp and torque on the first run were improved over the tbi heads and flat tappet cam through the whole range but I think there is still some timing problem holding it back by a lot.

Edit: I think the time in the AE tables is adding time to injector pulse width. If that is the case, then the 96 tbi G van looks to lean the TPS AE table at the very top not increase it compared to 1995 and the 193 heads. It's not bad drivability wise as is at all, but I would rather not be that lean even for a second. There is a lot of talk about AE here in past threads, but not many specifics, also the older tbi computers appear to have a fewer tables. I think I will test the theory by increasing the time slightly in the two main tables and see what the result is.

The only 96 Vortec head G-vans I have seen had the governed TBI units and used the 366/427 big truck injectors. I think GM swapped injectors, made a few tweaks and sent them out the door.

I would multipy the whole TPS AE table by 1.25 and the MAP AE table by 1.5 and see if that gets you closer. It is easier to trim back too much fuel than deal with the consequences of not having enough. The time in those tables is pulsewidth added asynchronus. The PCM drives the injectors both at the same time to deliver it. uSec is microseconds fwiw. From what I remember 1000 usec is 1 msec.

**Fast355** · 01-13-2019

There are also tables to modify AE based on temperature and RPM. I need to look at the tables again but I also seem to remember their being AE decay tables. The decay tables control how long the additional fuel is injected. From what I remember lower numbers mean a longer AE shot. TPS AE responds more quickly but also decays out much more quickly than MAP AE.