DIYPNP Documentation for 1988 – 1991 Chevy TBI V8

NOTE: The DIYPNPD56-K Kit has been discontinued as of 8/30/18.

1988 – 1991 Chevy TBI V8

1992 uses the same settings, but the pinout is different.

Test Vehicle Details:

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

[ARCHIVED] What to buy:

1- DIYPNPD56-K Kit (DISCONTINUED)  This is the main DIYPNP Kit including the Chevrolet Delphi 56-pin connector and all components, case, etc.

1- Tuning Cable  This is the same DB9 serial tuning cable used in other MegaSquirt applications.
1- USB Adapter  This is a DB9 serial to USB adapter.  The adapter is needed when the laptop or PC you are using does not have a built in DB9 serial port.
1- StimPower  This is a power supply that is normally sold to power a stimulator, but another use is it can be plugged directly into the DIYPNP mainboard to power the ECU directly, allowing you to load the basemaps and do limited testing on the ECU prior to installing the ECU in your vehicle.  It is particularly nice to be able to flash the firmware and load your configuration on the bench instead of in the vehicle, and allows for less risk of damaging something on the vehicle due to incorrect settings.
1- PNP_IAT-A or PNP_IAT-S AFM/MAF Delete kit. This is a simple kit with an IAT sensor, wire pigtail, crimp pins to poke into the AFM Connector to run the signal back to the ECU, and a steel or aluminum bung (hence the -A and -S in the part numbers).  Perfect for getting rid of a restrictive AFM/MAF with your DIYPNP install.

What tools you’ll need:
Soldering Iron, Solder, maybe some desoldering braid in case you make a mistake.  Small phillips screwdriver.  That’s about it.


Startup Maps

Base Configuration .msq files to help you get your car fired up safely and quickly.  Ready to tune.

We’re including these maps prior to showing you how to jumper your DIYPNP up.  There’s a reason for that.  The base ignition settings contained in these maps should be loaded on your DIYPNP before you power your car up (with the key) with the DIYPNP installed.  This is to prevent damage to your ignition system in case the default settings are not correct for your vehicle. Note that you can power up the DIYPNP off the vehicle on a power supply connected to the power jack next to the DB15 connector.

So here’s our recommendation–  After you complete basic assembly, Power up your DIYPNP one of two ways.  Either plug a Stimulator Power Supply into the front panel of the box (the easiest way), or, start the Jumper Section below, but only connect the power and ground wires to start with.  That way you can plug the DIYPNP into your factory wiring harness and safely power it from your car.  The third option, if you’ve fully assembled and jumpered your DIYPNP already, is to unplug your coils from their power connectors before plugging the DIYPNP into your factory harness and powering it from there.

Then and only then, you can flash the firmware on your DIYPNP to the MS2/Extra firmware if you haven’t already, and then load the startup map provided to help you get your vehicle started.

Click Here to Download Startup Maps for this Vehicle

Once the vehicle is started, you will need to use the MS2/Extra manuals to set the base timing and begin to tune the vehicle!  This is critical!  Do not drive an untuned vehicle!

DIYPNP Jumper Configuration

This section will cover the standard, basic jumper configuration required to get the vehicle running using your DIYPNP.

Vehicle Information

Engine:TBI V8

System Information

Main Board:DIYPNP v1.5
Minimum Code VersionMS2/Extra 3.1.0

Edge Pin Connections

VR2 IN +
INJ1**** D16
INJ2**** D14
5V*** D5
ALED** D11

Pull Ups

OPTO+470 Ohms5V

High Current Drivers

OutputEnabledTo Pin

Knock Circuit

EnabledSensor +Sensor –

I/O Circuits

CircuitInput FromOut Pin ToPurpose
Relay 1
Relay 2
Input 1
Input 2

Miscellaneous Jumpers



* Fuel Pump to High Side in
* High Side out to A1** Fan 1 WLED
** Fan 2 ALED*** Give 5V to D5 for HEI bypass signal
**** Need to add injector resistors

Ignition Settings

Spark ModeBasic Trigger
Trigger Angle5.5
Oddfire Angle
Use Cam Signal
Ignition Input CaptureFalling Edge
Spark OutputGoing High (Inverted)
Number of CoilsSingle Coil
Dwell typeStandard Dwell
Cranking Dwell6
Cranking Advance10
Maximum Dwell3
Maximum Spark Duration0.5
Spark Hardware Latency38
Trigger wheel teeth60
Missing teeth2
Tooth #1 angle
Wheel speed
Second trigger active on
and every rotation of

Other Changes/Considerations

This section will cover changes that need to be made to the DIYPNP that go beyond the standard I/O jumpering, such as intake valve butterfly activation, on/off VVT activation, or other customizations to address the specific needs of a vehicle.

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.



Sensor Calibration

  • 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 / CResistance In Ohms
    • 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    FResistance In Ohms
    • 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’.

Read the Manuals, You are Responsible for your own results!

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 at  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.


We’d love to hear your feedback on our DIYPNP Application Docs.  Click Here to offer feedback/suggestions!