Toronto Trans Ams

Trans Am Tech Talk => EFI => Topic started by: Wheelman on August 17, 2018, 02:33:52 PM

Title: FiTech EFI Conversion Basic Information
Post by: Wheelman on August 17, 2018, 02:33:52 PM
Many Pontiac owners have been converting to EFI systems for performance, mileage and tuning improvements.

I recently converted from a Cliff's 800CFM Quadrajet to a FiTech EFI system. The conversion process seemed like it was always "1-step forward...2-steps back", but I was rewarded with instant starts and neck-snapping performance.

We can use this EFI section to collect and provide information to guide you through the fuel system, TBI installation and tuning.

Below is some basic information concerning setup and tuning copied from the FiTech Owner's Facebook page.

Resetting to a stock calibration:

From the main menu go to the very bottom and select Write Cal To ECU. Once in this menu scroll down to the second to last selection, it should say Default v8 T195. Once on this file select it and it will download to 100 percent. After this is done it will revert to the main menu. Now go to Go EFI Initial Setup, then Engine Setup, now input all of the parameters that are needed for your application, making sure to save each one individually.

After you have entered your information and saved it go up and select Dash Board. Once in dashboard turn the ignition key off and wait for all the data to black out. Once this happens turn the ignition key to the on positon and start the car.

IAC Steps:

Turn the driverís side throttle adjustment screw IN (clockwise) half a turn to start with, with that done turn the key on and go to dashboard and find TPS and make sure it reads zero. If not, then shut the key off and wait for the numbers to go black then turn the key on again. Once that reads zero start the vehicle and find IAC Steps on dashboard. This number needs to be within 3-10 at warm idle. If the number reads zero then slowly turn the screw OUT (counter clockwise) until the IAC steps reads between 3-10. If the number is above 10 then shut the vehicle off and turn the screw IN as stated above and repeat the process until the IAC steps are between 3-10.

Cranking fuel adjustments:

With the key on go to the Go EFI Tuning menu, find Crank and Warm up. There you will see three cranking fuel selections. For cold starts add or subtract fuel from Crank fuel 65f, for hot starts add or subtract fuel from crank fuel 170f. Changing these settings should help with your start up issues along with setting the IAC. A good starting point is to change the settings in intervals of 10 to find which way you need to adjust the system to work better.

Accel pump/ Fast Accel adjustment:

If the system is having a hesitation or bogging issue, and you IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. To start with turn the key to the on position and then find Go EFI Tuning on the main menu and press enter. Then find Accel pump and press enter. You will see a menu with multiple different settings, you need to focus on the Accel pumps (20f, 65f, 170f) and Fast Accel (20f, 65f, 170f). These setting adjust how much fuel, at varying temperatures, the system injects when you accelerate. Accel pump is used for any normal throttle input, Fast Accel is for any fast throttle inputs or Wide Open Throttle.


If the vehicle has a hesitation (when you step on the throttle and the engine does hangs and/ or almost dies and then suddenly take off) this normally is a lack of fuel so you would fix this by increasing the Accel Pump (for normal throttle input hesitations) or Fast Accel (for fast throttle or WOT inputs). You would make changes starting in increments of 10, to the temp range that you are finding the issue to reside in.

Bogging/engine loads up/slow to respond: If the vehicle is bogging (when you step on the throttle and the engine is slower/sluggish to come up to a higher rpm) this is normally caused by over fueling. To fix this you would need to reduce the amount of fuel it is injecting as an accel pump shot. To do this this decrease the Accel Pump (for normal throttle input hesitations) or Fast Accel (for fast throttle or WOT inputs). You would make changes starting in increments of 10, to the temp range that you are finding the issue to reside in.

Choosing a cam selection:

Cam selection is based on vacuum load of the engine. Cam 1 is for 15Hg or above, Cam 2 is for 10Hg to 15hg, Cam 3 is 8Hg to 10Hg, Cam 4 is 8Hg to 6Hg. These are estimates and you may need to switch between them if the vacuum load is between two different cam settings to get the engine to run better for your application.

Idle Return:

If the engine is not returning to idle quick enough for your liking or is dropping too quickly and killing the engine then you may need to adjust the rate at which the injection system comes to an idle. To do so you need to go to Go EFI Tuning, then find and select Idle Control. Once in this menu you will see several settings, the only one we are going to work with is Decel open IAC. This number should be at zero as a base setting, by going negative you are reducing the amount of time it takes to return to Idle, and by going positive you are increasing the time it takes. Normal procedure of adjustment is to add or subtract 10 to start with and then adjust it to your liking or what the engine needs. Then once the setting is input save it to the ecu by pushing the joystick IN, the handheld will show Send To ECU Successful. Once this is done make sure to go back to the dashboard and turn the key off until the numbers clear out on the value side. This shows that the system has saved.

AFR Target Adjustment:

AFR: Air Fuel Ratio. Some vehicles may have greater needs for fueling that the self-learn may not be able to adjust in a great enough amount to operate correctly right out of the box. The injection unit is always trying to maintain a targeted AFR throughout its operation. It is either adding or taking away fuel at any given time from its current fuel table in order to do this. The AFR target is what the computer is constantly adjusting for (the higher the number the more lean the mixture, the lower the number the more rich the mixture is), but some engines need different fueling depending on the CID and cam they have. To adjust these numbers you must go to our Go EFI Tuning menu then to AFR targets, typically adjusting any AFR target should be done .01 at a time either up or down as the AFR has drastic effects on how the engine runs

Once in this menu you will see 10 settings you can adjust. Number 1 is for Idle AFR which can range from 13.4 to 14.7 on average depending on the engine. Adjusting this setting will help idle quality and takeoff from an idle. The 1100, 3000, 6000 at 45kpa cruise are your cruising AFR ratios, these can vary from 13.8 to 14.7 on average depending on the engines needs and your desired fuel economy. The cruise AFR only effects cruise so it will not affect your acceleration or other AFR settings. WOT 1100, 3000, 6000 are your acceleration enrichment settings and are used for adjusting the desired fueling for accelerating under either part throttle or WOT. The average for these settings only ranges from 12.4 to 12.7, any accelerator needs beyond that will require one of our technicians to go over with you. Boost 1100, 3000, 6000 180kpa should stay within 11.5 to 11.7 on most engines with boost, any further adjustments to your boosted AFR settings should be brought up with one of our technicians.

These are a basic overview of the most common setup questions

It's very important to make sure the front and rear  throttle blades are synced together so they both START to open at the same time on each throttle body before the linkage between them is fitted. Before you do this back of the rear idle screw on each throttle body and DONT use it. Only use the front idle screw just like a normal carburetor. Once thats done adjust the linkage between front and rear throttle bodies then set your IAC. To set the IAC only use the front idle screw on the rear throttle body and recheck this setting when the engines at normal temp then adjust the front throttle bodies front idle screw so it just touches. The throttle position sensor is on the front throttle blades on the rear throttle body so it's important everything is based around this being correct.

This fuel table is only for a running engine.  Cranking fuel does not use this. 170F Cranking fuel sometimes needs to be reduced for some engines for hot starts (Prime and Cranking Fuel, and Cranking IAC, and distributor position,  are the only things used during cranking) .  I often check which way it wants to go by doing different types of shut downs. If revved high and then close throttle and key off (dries out the manifold) , let it fully power down (<15 seconds) and restart. Compare that to just keying off. If both are acceptable, wait a few minutes after just keying off, and check again.  If not, make a change by 15% or more, and try again. When the 3 types of restarts are ok, you should be close. One problem you might be fighting is poor fuel pressure retention, and that might be causing it to need a long prime. If you cycle the key a second time and prime twice before starting and see it starts fine, it could be that.
If cracking the throttle a little while you crank helps a lot,  it's usually too rich.

You do. And yes, most "non-stock" motors like between 13 and 30 for idle steps, full warm.