Beast5spdGTA

Kinda a contiunation of a post about memcal failure below. I got a moates adapter and tried using the stock untouched prom with a burned chip, car runs but with check engine light and I'm not able to hook up through a scan tool.

Same with the stock GM chip AUJP on label.

Tried a downloaded "AUJP" bin and car ran really bad (wouldn't idle), but seemed to on and off connect through scan tool.

I've burned probably 100+ chips for a TBI car (the same chips actually). So basically looking for some kind of help, the car runs and is driveable with the stock PROM, but I really need to get some tuning done 10 mpg city and 17 mpg highway is hurting aside from the lack of power, just waiting to be unleashed.

Grumpy

Try clearing the prom with burning it with a .bin that's JUST FFs.
Maybe twice, and then try using it with a .bin.

Grim Reaper

I noticed two things (if it's for the 1989)....

1) Have you converted to SD 730?

2) Are you running a 5 speed?

The AUJP is an SD and auto bin. You need something different if you are running MAF and/or 5 speed.

SATURN5

If I may throw in a tangent....

Personally, with a blower being added soon, why waste time running N/A code. I'd repin the 730 to match the SyTy and burn a copy of SyTy ($58) AYBN. $58 supports both stick and automatic, and puts fueling control back to the ECM. No need for a FMU.

$58 is switchable between 1 bar and 2 bar, stock,(and 3 bar too(not stock)).

I ran the Malibu with a four speed T-10 all summer without problems. I have since swapped to a T400.. all that I changed was a bit flag in the bin.


A $58 bin file is 16K, so you need to load the file into the upper half of a 256 flash. Start $4000 or double the bin to 32K.

BW

Beast5spdGTA

The car is a manual, I didn't even think of the auto/manual thing.

I did convert to SD and plan to convert to the sy/ty code soon. The main reason for not going straight to the sy/ty code was I needed the car to run quick and drive a 1500 mile trip, so using the 730 and stock chip cut down some varibles. I also thought the sy/ty code needed a 2 bar map, which i don't currently have.


Anyways, I'm all for re-chipping to run the sy/ty code if that's the easiest solution and I won't have problems running NA with the 1 bar map for a month or so.

Beast5spdGTA

I took the bin from a 305 5 spd and that worked, car actually "feels" better with the AUJP bin. Maybe the spark curve in the auto bin masks everything that is wrong with the tune. Hopefully I'll be able to fix that through tuning.

Anyone have any insight to why the AUJP bin and stock prom from GM worked fine in my car, but the AUJP bin burned on to an Atmel chip wouldn't work?

Grim Reaper

It may not have "burnt" perfectly well the first time. I've occasionally experienced that even though it will compare great also. Just one of those reasons you should always have a spare Memcal (known good) with you when you try a "new burn". I had one SES light show up some 30 minutes after everything ran fine.

Also, you may want to do some "binary compares" between the 305 5-speed and AUJP bin to see the differences in the settings. Things like spark advance and AE could be reasons why a bin (AUJP) which is not the right one to use for a manual car feel better. I assume you resized the injector cosntant and cylinder volume for the 305 bin.

But those "binary compares" can be very enlightening and a great learning tool.

Grumpy

Nope, don't work that way, won't happen, can't possibly make sense to do that.

One other thought is blind testing.
Do several chips, and blind test them for how they work.

When we were originally doing Promgramming 101, we just tried every .bin file we could. 6 cyl, 8, auto, man, anything we could get, and then tinkered with the various combinations until we reasoned thru alot of what was going on.

Beast5spdGTA

That's a weird cociendence if it was just that burn that worked and then the next 2 also worked with the manual bin. I tried almost 20 burns out of 4 chips with no luck with the AUJP and varients.

Yes, I did change the inj. constant and cylinder displacement.

Here's a question, Why is the 305 at 815cc/cyl, yet the car ran lean, but changing it to ~712cc(same as AUJP), the BLMs are more normal, (richened up the tune). Just a conversion error in my ecu file?

As far as the auto bin feeling better, I think it's just the auto bin has a lot less spark below 1500 rpm, where I now have nice jerky hesitation at ~10% throttle or less. This is probably b/c it's running too rich correct?

I haven't had time to look at anything really, just driving to and from school. Hopefully the WBO2 I have will work like it should and make tuning a snap.

anesthes

iTrader: (12)

Injector sizing becomes much more critical when running $58..


I think i'd rather control timing with the ECM under boost than fuel. Or if I was controlling fuel, I think it would be pressure + pw, not just pw..

If FMU/regulators were not useful, then GM woulda just done everything in the ve tables, wouldn't they? Why the vac line method?

-- Joe

Beast5spdGTA

I'm pretty sure why you have a vac. line attatched to the regulator is to compensate for the pressure differences inside the intake manifold.

i.e. at WOT in NA the pressure inside the intake manifold is at 1 atm ~ 14.7 psi, so your fuel flow is based on a pressure differential between the fuel rail and intake manifold times pluse width.

Say 43psi - 14.7psi= ~28psi differential.

Now in a boosted car running 10 lbs boost (24.7psi in the intake at WOT) would need the rail pressure to be 53 psi to keep the pressure differential constant, so the same pulse width would flow the same amount of fuel as NA. (Of course you'll need more fuel in the boosted application).

The fuel pressure won't be constant running the $58 code, I believe it'll work just like the 730 except that VE can go above 100% and the MAP goes to 190 kpa instead of 100 kpa.

anesthes

iTrader: (12)

Yeah, but why have it on a MAP car to begin with? Perhaps maybe when GM introduced MAP on the TPI, they didn't want to re-engineer it. Or maybe they figured they could sell cheaper injectors and use fuel pressure to compensate for pw range.


Thats not really a linear thing though, but I see your point.

But it will be constant. You have the same regulator. So you go from 38 to 45 psi, or 45 to 50, or however you have it set. But point is, you go from this really small pw at 45psi, to this really large one under full boost.

My point is, you need to figure out your bare min fuel needs at whatever pressure (vac connected) and set the smallest pw. Then figure out your MAX fuel needs at your static pressure (vac disconnected) and set the largest possible pw at the highest RPM you can pull. Then hope your injector matches your range appropriately.

The neat thing about the FMU is, your injector sizing doesn't have to be an exact science. You can adjust the FMU, then ve after that to compensate.

So I don't think $58 is generally terrible, i've considered it myself at times. I just don't know if i'm ready for >100kpa fuel on pw alone.

-- Joe