What If? $8D (1227727 ECM) for TBI

[yelruhde]

I still have my test bench set up and can give it a try.
What memcal should I use with this bin? A 7427 tbi memcal?

Did the bin file work?
I still do not have a light on my truck.

[JeepsAndGuns]

Sorry about that, I've been real busy lately and havent had a chance to try it out. I did however look at it in tunerpro and compare it to a stock aujp bin.
What bin is yours? Was it made from aujp? I found a lot of really strange differences. Some random parameters are like stupid crazy high numbers, the spark tables do not look like they should, and fuel tables are a little odd. Are you sure this is a $8D bin? I have seen odd stuff like this when I have looked at bins with the wrong xdf.

[yelruhde]

Yes, it is 8D. At least that is the title of the xdf file.

What makes the numbers crazy high?

[yelruhde]

The bin does not throw a code for me and definitely did something. The truck had much more off idle and low end torque, and would break up around 4,500. When it is set to v6 mpfi mode it runs straight past 5000 without a problem. Then ecm fried this weekend at the end of a 200 mile trip. Here's to keeping spares in the vehicle when doing something stupid.

It may be a setting in the bin file, it may just be the hardware can't do it alone. I have another spare on order and don't mind trying it again...but I'm new at this and don't know where to look for improvement in the files. All of the injector pulse times were cut at first by a third, then down to a quarter of the original value. This didn't seem to make any difference.

I don't mind being a guinea pig, but need some guidance.

[JeepsAndGuns]

So are you running a V6 with a 7730/7727 and tbi?

Difference tool found 598 differences between this and a stock aujp bin.
Not sure if it makes a difference, but code mask is set to AA to disable checksum.
One odd one, is speed sensor is 4006.96 on stock aujp, on yours is 102400.00.
Timing table looks significantly different, and timing doesnt drop down at higher map readings and is kinda level across the board. Never seen a timing table like it.
Also lots of other random parameters are different, not by much, but just enough to make you wonder why.

Is this a bin you have modded from a stock bin, or is it one you got from someone else?

I hope to have time tomorrow to run a test on my test bench with 0x293 set to 10 for 4cyl.

[dave w]

Did you install the resistors? http://www.vishay.com/resistors-line...product-30201/

dave w

[yelruhde]

There are not any resistors installed.

There is a 40 ppr speed sensor coming out of the transfer case. The ridiculous number makes up for it.

Most of the spark timing is lower. The numbers that are higher came with from enginne analyzer. So far there haven't been any knock problems.

[RobertISaar]

the lack of resistors probably killed the injector drivers.... just saying.

[yelruhde]

the lack of resistors probably killed the injector drivers.... just saying.

I don't think it is this simple. The truck has been running without a hitch as a v6 MPFI for months now. I told it to fire every crank pulse using the Crank pulse multiplier vs Ref Pulse 1 - 24, divided all of the pulse width tables by 3 and ran it with a v6 mpfi memcal. It ran nearly the same as it did before, but I have no way of telling how often the injectors were actually firing doing this.

Then when it gets changed to TBI mode the entire behaviour of the engine was different. The obnoxious off idle stumble was gone, but the engine would break up past 4,000. And the fuel mileage was cut in half. 10 mpg with a 4.3 liter is pathetic. The only parameter changed was 0293 to 10 and a tbi memcal was installed.

It felt like the pulse width was over lapping. Almost as if the single driver was being switched from one injector to the next while under load. It doesn't make sense that this would happen. The amount of fuel and tables used to calculate the amount were the same. I feel like there is a base pulse width parameter or value plugged in somewhere which needs to be changed and I can't find it.

Is this wrong?

[JeepsAndGuns]

I fired up my test bench and ran a aujp bin with 0x293 changed to 10. I used a 100% stock un modded 7427 V8 memcal. I did not get the cylinder select error. But, is it firing the injectors correctly for tbi? That I have no way of knowing.

[dave w]

In an eailer post I wrote "I had noticed the '7730 2.5 Liter TBI Jumper D5 / D7 Injector Driver Low. I was thinking there would be a '7727 configuration that would be set for low Z injectors." I think the injector driver is not functioning correctly, if the engine looses power (fuel) at 4000? The thinking I have is; the TBI Injectors (low Z) will work in MPFI mode if resitors are used. The thinking I have is; the factory '7727 V6 memcal is Ok to use for a TBI 4.3 V6 (with resistors). The thinking I have is; the 7727 will only operate one low z injector, if there is a TBI jumper similar to the '7730 jumper setting. The thinking I have is; the voltage telling the '7727 to operate MPFI or TBI needs to be verified on the memcal (I'll need to look back on my notes to figure out which memcal to measure voltage on).

dave w

[dave w]

I fired up my test bench and ran a aujp bin with 0x293 changed to 10. I used a 100% stock un modded 7427 V8 memcal. I did not get the cylinder select error. But, is it firing the injectors correctly for tbi? That I have no way of knowing.

I'm wondering what voltage pin 56 has with a 100% stock '7427 memcal? Look back at page 3 post 41 of this tread from 1project2many.

dave w

[yelruhde]

In an eailer post I wrote "I had noticed the '7730 2.5 Liter TBI Jumper D5 / D7 Injector Driver Low. I was thinking there would be a '7727 configuration that would be set for low Z injectors." I think the injector driver is not functioning correctly, if the engine looses power (fuel) at 4000? The thinking I have is; the TBI Injectors (low Z) will work in MPFI mode if resitors are used. The thinking I have is; the factory '7727 V6 memcal is Ok to use for a TBI 4.3 V6 (with resistors). The thinking I have is; the 7727 will only operate one low z injector, if there is a TBI jumper similar to the '7730 jumper setting. The thinking I have is; the voltage telling the '7727 to operate MPFI or TBI needs to be verified on the memcal (I'll need to look back on my notes to figure out which memcal to measure voltage on).

dave w

It wasn't losing power in the loss of fuel sort of a way. It was pumping black smoke out of the tail pipe. Somehow changing 0293 to 10 made a tremendous difference in the way it calculated the amount of fuel...or it came to the same value and shot that in 6 times per cycle instead of twice. Perhaps the best thing to try is if I change the injector value to the flow of the tbi injector and not the per cylinder value which is currently in the bin file.

I would rather wire in a solid state relay then the resistor. The relay would take the load off of the driver instead of dropping it by a factor. It ran like that with the old tbi vcm. Crydom makes a 10 amp SSR with a 1ms on time max. The engine shouldn't notice this.

[RobertISaar]

instead of a SSR, you could use a FET instead... probably a lot cheaper, a better response time, and higher amperage capability.

[EagleMark]

It wasn't losing power in the loss of fuel sort of a way. It was pumping black smoke out of the tail pipe. Somehow changing 0293 to 10 made a tremendous difference in the way it calculated the amount of fuel...or it came to the same value and shot that in 6 times per cycle instead of twice. Perhaps the best thing to try is if I change the injector value to the flow of the tbi injector and not the per cylinder value which is currently in the bin file.

I would rather wire in a solid state relay then the resistor. The relay would take the load off of the driver instead of dropping it by a factor. It ran like that with the old tbi vcm. Crydom makes a 10 amp SSR with a 1ms on time max. The engine shouldn't notice this.

Sounds like Syn/Async fueling? Is there a way to see in ADX data?

1 ms is going to be way short...