12P Pontiac Fiero 2.5 4 cylinder, manual tranny

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12P Pontiac Fiero 2.5 4 cylinder, manual tranny

Postby cerulean » Sun Apr 21, 2013 9:03 am

Hi,

First time poster, who has been lurking for a while. I just converted my Fiero over to a 1227165 running $12P.

The 1984 Fiero uses a previous generation of ecm. So, I cut off the original Fiero ecm plugs and rewired (adding an IAT sensor) for the 7165:

Wiring.JPG
Wiring.JPG (225.81 KiB) Viewed 4204 times


I started with the $12P-V111-IsuzuG200W-fixed.bin from the $12P Custom Tunes thread. The only thing I changed was the flow rate.

$12P-V111-Fiero_2.5_tbi.bin
(32 KiB) Downloaded 231 times


The memcal (and 1227165) that I'm using came from a 1989 Chevy S10 4 cylinder 2.5 with TBI. I removed the original flash and soldered in a socket to use ST27SF512 chips.

I got the car running on the attached bin after fixing a couple of wiring and sensor issues. Here is a screen shot of the TunerPro config and a log of it idling:

TunerPro.JPG
TunerPro.JPG (35.97 KiB) Viewed 4204 times

Idling.xdl
(86.75 KiB) Downloaded 221 times


Before I take it for a ride, I had a couple of questions.

Should I change the bin to 2 Cylinder (TBI) mode? What is the difference between the memcal netres setting and the setting in the bin?

When I set the flow rate, I scaled it based on the value in the Isuzu bin (Isuzu flow rate * fiero displacement / isuzu displacement * fiero injector size / (isuzu injector size * 4)) rather than using the kinjiflow spreadsheet because I wasn't sure of some of the settings in the spreadsheet when doing a TBI setup. Is my flow rate in the right range for my setup?

In the log file, it looks like knock sense is on. What setting do I change to disable that?

Also, a couple of the values looked off in tuner pro (highlighted in red).

Overall, the car idled well. It seemed to adjust the idle down as it warmed up, but I'd appreciate it if someone with some experience took a look at the attached files to do a sanity check on how I set the Fiero up.

Thanks,
Bob

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Re: 12P Pontiac Fiero 2.5 4 cylinder, manual tranny

Postby VL400 » Sun Apr 21, 2013 10:57 am

cerulean wrote:Should I change the bin to 2 Cylinder (TBI) mode? What is the difference between the memcal netres setting and the setting in the bin?


The memcal netres controls how often the injectors are fired, while the bin setting changes the RPM calculation. Being a TBI setup your memcal will be fine and fuel will be injected on every reference pulse to the ECU. The cylinder number in the bin should be set to 4.


cerulean wrote:When I set the flow rate, I scaled it based on the value in the Isuzu bin (Isuzu flow rate * fiero displacement / isuzu displacement * fiero injector size / (isuzu injector size * 4)) rather than using the kinjiflow spreadsheet because I wasn't sure of some of the settings in the spreadsheet when doing a TBI setup. Is my flow rate in the right range for my setup?

You can use the kinjflow calc and change the injection pulses per cycle to 4. Is the fiero injector size around 22lbs/hr?


cerulean wrote:In the log file, it looks like knock sense is on. What setting do I change to disable that?

There is some info in the FAQ, see "How do I enable or disable the knock filter?" viewtopic.php?f=7&t=1396

The Bin your using has it disabled, you will still see knock counts but the knock retard will always be 0deg.


cerulean wrote:Also, a couple of the values looked off in tuner pro (highlighted in red).

O2 voltage is pegged rich, it may be a cold sensor or just needs some tuning! A wideband would probably make life easier if you dont have one already.

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Re: 12P Pontiac Fiero 2.5 4 cylinder, manual tranny

Postby cerulean » Sun Apr 21, 2013 11:49 am

Thanks for the quick reply.

VL400 wrote:
cerulean wrote:When I set the flow rate, I scaled it based on the value in the Isuzu bin (Isuzu flow rate * fiero displacement / isuzu displacement * fiero injector size / (isuzu injector size * 4)) rather than using the kinjiflow spreadsheet because I wasn't sure of some of the settings in the spreadsheet when doing a TBI setup. Is my flow rate in the right range for my setup?

You can use the kinjflow calc and change the injection pulses per cycle to 4. Is the fiero injector size around 22lbs/hr?


The Fiero has a single 60lb/hr injector.

I changed the pulses value to 4, but am not sure about the injector size (lb/hr) and cylinder size for a tbi setup. Do I enter the injector size for the single injector (60 lb/hr)? Do I enter 2.5/4 in the cylinder size for a tbi setup?
Kinjiflow.JPG
Kinjiflow.JPG (78.53 KiB) Viewed 4190 times

VL400 wrote:
cerulean wrote:Also, a couple of the values looked off in tuner pro (highlighted in red).

O2 voltage is pegged rich, it may be a cold sensor or just needs some tuning! A wideband would probably make life easier if you dont have one already.


I don't have one yet. I need to do some research.

Regards,
Bob

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Re: 12P Pontiac Fiero 2.5 4 cylinder, manual tranny

Postby VL400 » Sun Apr 21, 2013 12:15 pm

TBI is not something I have much experience with, but it looks like the kinjflow calc has not taken in to account the inj pulse per cycle value. The calc in cell B10 needs to reference L8. Try with 0.083 as a start, but at the end of the day so long as the VE table gives the tuning range you need (ie does not need to go above 100%) then your ok.
Attachments
kinjflow.png
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Posts: 3
Joined: Tue Feb 12, 2013 1:31 am
Location: Shrewsbury, Massachusetts, USA

Re: 12P Pontiac Fiero 2.5 4 cylinder, manual tranny

Postby cerulean » Sun Apr 21, 2013 10:58 pm

VL400 wrote:Try with 0.083 as a start, but at the end of the day so long as the VE table gives the tuning range you need (ie does not need to go above 100%) then your ok.


I'll change it to 0.083 and take it for a ride.

Thank you.

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