7730 - Rich on Cranking/Startup

**bnevets27** · 05-09-2013

Hi all,

Background info:
Car is a 1986 Pontiac Fiero GT with a 99% stock 2.8L (ported exhaust manifold, deleted egr)
A few years back I swapped/upgraded my stock ECM to the 1227730 ECM. Overall a great decision. There's a bit of a story of how for a while it was running rich, but I'll spare you the tale. Long story short, I had bigger injectors installed then I was aware of, they were supposed to be stock. The original chip and a few modifications to it was done through the mail, and besides chasing the run rich issue all was well (to the best of my knowledge). To correct my rich issue, make other small modification and learn how to tune, I bought a moates Ostrich 2.0 which will be permanently mounted in the car.

Current problem:
When the car first starts up its REALLY rich, smoke, very strong gas smell etc. It doesn't have any trouble actually starting though. Once it warms up it seems to be much better but possibly still a little rich (can't remember, as it was fall when I last drove it) . When I was have the rich issue before, it seemed it would get worse and worse over time. I would change the oxygen sensor and it would be greatly improved but eventually get worse and worse again. My guess was the rich start up was carboning up the O2 sensor. So I've installed a heated O2 to help keep it clean, not a solution but hey it can't hurt. But I don't see how the O2 could/should effect the running right after start as it would be in open loop....

My main question is, what parameters would I change to lean up cold running AFR and possibly cranking fuel amount (seems like its dumping a lot of fuel). I have attached my bin bellow if anyone could take a quick look. I have a lot of learning to but I really want to get rid of this rich condition so I can enjoy my car this summer.

Thanks for any of you input!

**RobertISaar** · 05-09-2013

BAWX is $88, so it will act a lot like A1/DF...

anyways, notes: a LOT of stuff changed....

is there a reason the knock sensor is disabled?
main spark has been played with a lot.
how much larger of injectors are you running? the BPC table has been reduced ~11%, but that would account for the change from 3.1 to 2.8 liters, not the injector size change as well.
the way EGR was disabled is odd..... it may work, but it's odd.

anyways, it looks like global fueling was changed in a lot of places, but not the injector scalars/BPC table.

**bnevets27** · 05-09-2013

Knock sensor is disabled as I was getting a lot of false knocks. There's no knock sensor on the engine from factory and not enough changed on it to make it necessary so I just had it disabled.

The injectors I'm running are stock. I had replaced them at the same time I did the ECM upgrade (learned my lesson to not do two chances at once). But the injectors I received from the seller were mislabeled and ended up not being the same size as stock. So I put my stock injectors back in. The issue it caused though is, I was telling my tuner that I was running rich and he tried to fix it (unknown to both of us the injectors were wrong)

If soo much has changed should I try a stock bin? I know it will need some modification to work on my 2.8 but I'm not sure it that was the reason for all the changes or not. Sounds like from what you said I would have to reduce the BPC table by about 11%, disable my knock and egr sensor.

**RobertISaar** · 05-09-2013

you have the $88 XDF i released/uploaded not too long ago? it's a full work(though i did find a small error, i'll be uploading a corrected version very shortly), you having issues with incredible richness immediately after starting, i would look at the "choke" tables and reducing the amount of fuel added before going into open loop. when in open loop, the commanded AFRs look to be reasonable.

that being said, i'm looking at the stock calibration for a fiero (AKYN), and it shows a BPC starting at 224, compared to yours starting at 164. that's a huge difference in fuel delivery. assuming the ECM swap calibration was based off of this one, there are some large changes to the main spark table as well. i would "import" as many settings from the stock calibration as possible before tweaking stuff.

**bnevets27** · 05-10-2013

Yes I do have the $88 XDF you recently uploaded. Thank you so much for doing that!!

I have possibly a bit more info from an email I originally received from my tuner:

04032008 60pp 86 Fiero 2.8 4-speed 7730 My Name Here BAWX 1.0

Shipping out to you is your reprogrammed mem-cal. I have made all of the changes to
its programming so it will work properly in a Fiero application. If you need to hook up a
scan tool to this ECM, you will need to set it up for a 1991 Chevy Camaro 3.1L vin T
engine and 5-speed manual transmission.
The mem-cal you sent came out of an 89 Chevy Cavalier with the 2.8L MFI V6 engine
and auto trans.

When you say "import" settings from the stock calibration do you mean from the stock Fiero (AKYN) bin? I did find another bin here that's exactly my car: HWX 86 Fiero 2.8MPFIHO 4 speed manual.bin Should I be using it, not sure if it makes a big difference?

So your suggestion is compare the stock bin from above (HWX) to my current BAWX and match as many settings as possible? Should I start with a stock BAWX bin also or from my currently modified one? I'll have to figure out how to disable EGR and Knock if I start from scratch. I assume there is no way to actually import bins and I'll just need to do a compare and manually do the changes?

If I am starting from scratch, in your opinion is there a better code mask other the $88 that would suit my application? I assume $88 is the right choice seeing as about the only difference is its for a 3.1L, AFAIK.

Thanks again for the help!

**EagleMark** · 05-10-2013

Are you the local Fiero guy that called me last week? If so I returned your call but never heard back.

**RobertISaar** · 05-10-2013

yes, you would need to do a lot of manual comparing/modifying...

APR would be a good place to grab data from, AKYN would also be a good place, they're both $24, but AKYN is from a 88 5 speed 2.8 fiero.... may be slight changes between the two calibrations, but i wouldn't expect much.

you won't be able to do a direct compare with BAWX, since while the two masks are very similar in how they use data, the way they're structured is in no way compatible.

starting with your already modified BIN or starting "fresh" with BAWX is your call.... neither way is going to be very short process.

disabling EGR is as simple as raising the minimum coolant temp to allow EGR to an unattainable number.... the way it's "disabled" in your BIN now, EGR is still enabled, but will command a 0% duty cycle.... it's kind of odd, since you'll likely see bits in the datastream indicate that EGR is active at times, when it really isn't. i also checked to make sure that no spark would be added or fuel reduced when EGR is active and it looks like you're okay there.

better options? possibly A1/nAst1, but i'll need to look into it more. certain applications never moved beyond 6D and 88 into A1, i have yet to figure out why for some of them, but for the most compatible starting point, one of the iron-head $88 BINs is bound to be your best bet. 6D(and it's 8F derivative for the TGPs) had some really odd things in it's calibration, but A1 and 88 are essentially slight reorganizations of each other, so they're both pretty well understood and documented. i've completely "imported" the $DF BINs BHAK and BCFA(3.4DOHC auto and manual) into nAst1 and it took a solid ~20 hours of correcting the DF XDF and copy/pasting settings for the first.... and probably 5 hours for the other. i really need to get ahold of the 2.8/3.1 5 speed W-body BINs and convert the latest $24, $88, $8F and in some cases $6D BINs into nAst1 to get that aspect done.