you caught my intrest
the knock sensor not needed -ya gm made engines without it
the iac(idle air control)how are you controling the idle?
the vss(vehicle speed sensor)load/speed=timing adjustment for/from the ecm to the dist/ignition

 

All you need is:
O2
Map
Tack Filter
TPS
Crank Sensor
Power Lead
Ground
Power to Fuel Pump
Injector Wires
The thing that plugs into the TBI unit it's self
and I believe there is a wire that splices into the coil + wire.


I think that is all I'm running (off the top of my head)

You will need to burn a chip to keep it from going into "limp" mode.....

 

The VSS tells the ECM how fast the vehicle is going via 2000 pulses per mile square wave. It's used on all GM TBI engines through about 1992.

Howell didn't have on on their system until they had to pass CARB requirements. Then, to achieve CARB they had to use the VSS in conjunction with a 4 wire O2 sensor. Without those items the engines ran too rich.

The engine should still run without the VSS connected, but it will run better when it's connected.

 

Sorry about that, I included the IAC, i was thinking of something else that was in the gm air cleaner housing i didnt use.

ill have to look into the vss. i figure if im going to all this trouble ill want it to run as well as possible.

Aaron, i definitely dont have anything going to the coil right now. Do you remember if that should have been the pink/black 12V switched ign wire, i think it was pin A6.
I have that set up as my ECM power source right now. Does it need to be spliced into the coil?

I had just planned on doing the nutter bypass to my ign/dist. But I think that will just bring the green wire from the module to the coil, so Im missing one wire to the coil.

 

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You will need to burn a chip to keep it from going into "limp" mode.....

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how do you do this? take it to a dealer?

 

[ QUOTE ]
[ QUOTE ]

You will need to burn a chip to keep it from going into "limp" mode.....

[/ QUOTE ]

how do you do this? take it to a dealer?

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No, dealer will laugh at you most likely.

Try it like it is, if you get a "check engine" light. Check the code. If it tells you that you have a bad VSS, knock sensor, or whatever. You can either get what your missing or have a chip burnned to run the system without the sensor.

In limp mode the check engine light comes on and you will experience a high idle. It will still run, just not very well.

affordablefuelinjection.com can burn you a chip for about $80 to $100, it will be tuned to your system. They can tune them for a cam or whatever.

As for the coil wire, I'm not sure. Go with what the original system called for, (from whatever vehicle you raped it from)

Keep us posted and good luck....

 

The first thing you do is get the harness connected to the engine and get it running. Then, and only then do you start debugging the system.

Keep it simple.... do one task at a time and get it done completely before you go on to the next task.

If you start burning chips, etc., you're going to get lost. The VSS, if it's needed by the donor system will fire a CODE 24 when you get the engine running. It will run without it. You'll need to get comfortable with the ALDL reporting system to recover codes.

Here's what that code means:

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Trouble Code 24 indicates that the Vehicle Speed Sensor (VSS) is not sending the expected (based on other system parameters like LV8, TPS, RPM etc.) signal to the ECM.

Code 24 will be set if vehicle speed equals zero 0 mph when:

* VSS indicates less than 2mph.
* MAP is less than 30 kPa.
* Engine speed is between 2200 and 4400 RPM
* TPS is less than 2%.
* Not in Park or Neutral
* No Code 21, 22, 33, or 34.
* All conditions met for 3 seconds

If the code was logged when the vehicle was in motion, the following should be checked:

1) VSS circuit open, shorted to ground, shorted together

2) Faulty Connections

3) Defective VSS

4) Defective ECM

5) A faulty or mis-adjusted Park/Neutral (P/N) switch can result in false Code 24.

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Once you get the engine up and running you can start running code checks and see what more is needed.

Burning chips can be done by you, with the right equipment. You'll need a laptop, some chips, cables, software and an EPROM burner. If you've got the laptop, there rest can be obtained for about the cost of having the chips burned... and you'll likely have three or four iterations before you end up with a great (not just good) fuel/RPM block map.

Download the MegaSquirt software, or the WINALDA software and get that laptop warmed up.