MSnS_Extra TPI install notes

[mobythevan]

Here are some various notes from the TPI install. Let me know if anything critical is missing. Files can be found by going to http://www.msefi.com then following the link at the MSnS_Extra forum.

 

TPI install notes:

 

MegaSquirt v2.2 hardware with relay board

MSnS_Extra_024s9 code

MegaTune v225b417

 

(be careful to follow megatune setup procedures and copy msns_extra.ini file or you won't get all of the new feature tabs)

 

TPI was from a 1987 305, 19# injectors, small cap distributor with 8 pin HEI module and external coil.

 

The idle air controller on the bottom of the thorottle body was left disconnected and idle was adjusted with the throttle plate. You can remove the cap over the throttle plate adjuster screw easily with a punch.

 

NOTE about IAC: from what I understand the IAC valve will be in the position it was last in when the car was shut off. Mine happened to be in a closed postion, but you may find that yours is open somewhat, you can turn the motor to close it manually I think. Otherwise you have to figure out a way to close it or remove it and block off the air inlets to the plenum/throttle body. Or else end up with air bypassing the throttle plate, high idle you can't get rid of. MSnS_Extra will NOT support control of the TPI IAC valve.

 

The recommended GM air temp and coolant temp senors were used. The TPI manifold already had places to install them. The stock TPS, FPR, injectors, TB, small cap ditributor, 8 pin HEI module, etc were all used.

 

Familiarize yourself with all the settings available in MSnS_Extra024s9 code. Go through all of the tabs and all of the settings and make sure everything is either disabled or set correctly for your system.

 

Go to the "code config" tab, then go to the "codebase outputs and function" tab

Turn off "This Cyl (MSnS)"

Select GM 7 pin HEI under "HEI ignition"

Set "LED17 function" to spark output

Set "LED19 function" to spark output B

 

Go to the "spark" tab and the go to "dwell settings"

select dwell control

cranking dwell = 6

running dwell = 2.5

minimum discharge =1.5

 

Go to the "spark" tab and the go to "spark settings"

Set "trigger angle" to 10

trigger angle addition 0

"cranking TIming" to "time based"

"crank angle" 10

"hold ignition" 0

"Spark output inverted" NO

"Fixed Angle" -10

"Trim Angle" 0

 

For all the rest of the settings in MegaTune you are on your own to decide if you use traction control, water injection, staged injection, NOS, etc etc etc.

 

The following mods need to be made to your MegaSquirt hardware to run 7 or 8 pin HEI modules (some TPI distributor use a 7 pin module, some use an 8 pin module. They both function the same)

 

Remove D5,D8,R10

Remove jumper between XG1-XG2

Fit wire between XG1 and right side of D5(non band)

Fit wire between bottom of R10 and small hole above D9(this is a +5v source - you could also use the hole to the left of D4)

Fit 1.3K resistor in place of D8 (1k-2k ok)

 

Add 1k resistor from (-) of D17 to the right (5v) side of R23

Run a length of wire from D17 (-) to X11

Add 1k resistor from (-) of D19 to the right (5v) side of R27

Run a length of wire from D19 (-) to X12

 

Connect the relay board in the normal manner. Hook up injectors, IAT, CLT, TPS, O2, fuel pump etc. (I did not use fast idle)

 

Connect pin R of the 8 pin HEI module to TACH input of relay board.

Connect pin B of the 8 pin HEI module to X12 (S2 connection on relay board)

Connect pin E of the 8 pin HEI module to X11 (S1 connection on relay board)

Connect pin G of the 8 pin HEI module to ground

 

Assuming that your not trying anything fancy you will already have the coil wiring in place for the stock GM coil. I suggest cranking the engine with the injectors disconnected and a timing light hooked up. Set the cranking timing to about 10 degrees BTDC. When the engine fires up check the timing at the crank matches the timing from your spark table.

 

That is about it. I have one problem left with the setup that I haven't had time to work on. More than 32 degrees timing causes the spark to jump to the wrong post in the small cap distributor. For now I limitied the max timing to 32 degrees until I get back to that.