DIYPNP Documentation for 1988 – 1991 Chevy TBI V8

The vehicle used for drawing up these application docs was a USDM 1988 Chevy Camaro 383 TBI with an automatic 700R4 transmission.  All factory electronics/ignition system components are in place and the factory wiring harness is in perfect condition.

Other notes:
Wiring harness from 1988 305 TBI engine used
Customer had previously installed a manual torque converter lockup switch
Two 80 LB TBI injectors installed

Fuel Injector Resistors

The factory fuel injectors for this vehicle are low impedance, around 2 Ohms each.  The injectors are wired back to the ECU in two banks on ECU pins D14 and D16.  We used two 10 Ohm 25 Watt resistors, one for each injector bank.  The wires would be run from INJ1 out to one side of the first resistor, and from the other side of the resistor out to connectorboard pin # D16.  You would duplicate this circuit for INJ2, and finish at connectorboard pin # D14.

Stepper Idle Motor Control

The stepper idle control motor uses 4 wires.

• Stepper circuit output 1A connects to connectorboard terminal C4

• Stepper circuit output 1B connects to connectorboard terminal C3

• Stepper circuit output 2A connects to connectorboard terminal C5

• Stepper circuit output 2B connects to connectorboard terminal C6

In addition to these four output jumpers, you will want to jumper from PT6, PT7, and PB4 (up near the DB15) on the main board to the stepper circuit on the connectorboard.  Jumpers for 12V, 5V, and GND will also need to be run from the main board to the connectorboard.

• If the valve works in the opposite of how you expect, you may reverse the PT6 and PT7 jumpers so they cross over from PT6 to PT7 and PT7 to PT6 rather than run straight through from PT6 to PT6 and PT7 to PT7.

Automatic Transmission

The transmission in this car is a fully mechanical model and needs no input from the ECU other than torque converter lockup.  The owner of this particular Camaro had installed a manual torque converter lockup switch in the center console before bringing the car to us.  The DIYPNP in this car had no control over the transmission.

• This vehicle has a variable TPS.  You should calibrate it properly from TunerStudio in the ‘Tools’ menu.  Choose ‘Calibrate TPS’.

  • Make sure the engine is off, and the key is on.

  • With your foot off of the throttle, click the ‘Closed Throttle ADC Count – GET CURRENT’ Button.

  • Put the throttle to the floor.  With your foot fully depressing the throttle, click the ‘Full Throttle ADC Count – GET CURRENT’ Button.

  • Click Close.

• Calibrate your CLT Sensor and IAT Sensor.

  • Again from TunerStudio, click ‘Tools > Calibrate Thermistor Tables’.  Make sure ‘Coolant Temperature Sensor’ is selected at the top.

    • For the CLT, use the following table with a bias resistor setting of 2490 ohms:

      Temperature    F / C	Resistance In Ohms
      48	7000
      87	1930
      146	560

  • Enter these values, and click ‘Write to Controller’.

  • Now you’ll do the same for the IAT.  Select ‘Intake Temperature Sensor’ at the top in the drop down box.

    • For the IAT, use the following table with a bias resistor setting of 2490 ohms:

      Temperature    F	Resistance In Ohms
      48	7000
      87	1930
      146	560

  • Enter these values, and click ‘Write to Controller’.  Now click Close to Exit.

• Finally, you should calibrate your O2 Sensor to the ECU.  To do this, click ‘Tools > Calibrate AFR Table’.

  • Choose your O2 Sensor from the list.  Choose Narrowband for the stock O2 Sensor.  Or select your wideband and the proper configuration of said wideband from the drop-down list.

  • Click ‘Write to Controller’.  Once finished writing, click ‘Close’.

This Application Doc is intended to assist you in your DIYPNP DIY EFI Installation.  We’ve done a fair amount of research, and actually tested on a similar vehicle to help ensure we can provide the most accurate information possible to make your installation go as smoothly as possible. That said, there are certain things you could do incorrectly, or certain things you could change up, that could cause you to run into issues.  Our tech support department will be glad to assist you working through any issues you might have, please contact us and give us that opportunity and we should be able to work things out for you.

Startup Maps included/attached to this Application Doc is intended only to help you get your engine started so that you can properly tune your engine.  The map will be setup properly for a stock vehicle matching the year/make/model/trim in the ‘Test Vehicle Details’ section at the top of this page.  If you have made any changes to your wiring, your ignition system, or other related components, this map may not be ideal for your vehicle.  You will then need to check and confirm the appropriate settings and properly configure your DIYPNP EMS for your altered vehicle.  Some maps offered may be more completely tuned that others, some may be just setup enough to get the car to fire up and idle with a little help from the throttle.  That’s when the tuning begins.

In short– We’ve provided you with the building blocks for an incredible EMS.  You are however responsible for the implementation and your own successes or lack thereof, but rest assured that we’re here for you and we’re going to do everything in our power to make sure your project is a success.

For more information on configuring and tuning your DIYPNP EMS, and for information on adding and tuning custom MS2/Extra features, read up athttps://www.msextra.com/ms2extra/.  In fact, everyone implementing this system should read that manual from front to back if you really want to harness the power of the DIYPNP EMS.