Okay first question, when I did my swap I used a truck harness from a 90' chevy truck, and I used a ECM that was given to me that came out of a 91 Camaro 305 tbi. Will they work together?

Now if the answer is no then that will answer the rest on my questions hopefully!

I have no power going to my fuel pump or the injector wires,
But I have power at the fuel pump fuse, relay and the inj.1 inj.2 fuses.

And I have no power going to the ALDL connector.

Any ideas?

 

Moved this to the TBI forum for you. Figured you're more likely to get an answer quicker.

 

Thanks!

 

So I'm guessing no one else knows either, ha!

 

what numbers are on the ecm? 8746? and do you have any idea what ecm the harness is from?

 

if you do have an 8746 ecm and the truck is a 7747 ecm then this may be helpful. search for a thread in the TBI forum named: Which wires need swapping? 1228746 to 1227747

 

Where would I look at on the ECM to see what number it has, and I don't have the ECM that went to the harness, but the truck was a 90' chevy 3500.

 

5.7

 

there should be a sticker on it that has numbers like 1228746. if the sticker is gone take off the rectangular cover and look at the chip inside. It should have 4 letters. you can use those four letters to figure out which ecm you have.

 

Sticker is worn away, took off plate and this is the info:

S/N # 153 721
Hypertech (c) '92
Pt# 122 362

G88IF
9235
M2732A-2FI
2IV FAST

There is also a sticker on the circuit board
*379091302281135*

 

not 100% sure but id bet thats an 8746 ecm. Your harness is probably an 8747. check the harness to see if it has a knock sensor, if it doesnt you may want to add that in later. the link i posted before should tell you which wires need swapped around to get that thing running.

On top of moving some wires around you will need to tune this. the ecm thinks it will be feeding a 305 when its actually feeding a 350. this will cause you to want your 3.1 back.

 

Just thought of something- You may want to look in to VATS. this could be why youre not getting power to the injectors. If so you may want to find a different ECM without VATS.

 

If I switch to a non VATs ECM would that give me problems with the car still not starting up?

 

And the harness does have a knock sensor

 

Cant say for sure without being there to test it. what happens when you turn the key? check engine light blink twice? gauges work? sensors power up?

 

Yes, everything comes on as normally, even turns over. Just no power to the injectors or the ALDL.

And last night I think I may have come across why my inj. Have no power, there is a third plug by the two main harness to ECM plugs and I traces the red a white wires to it and the pin that they are plugged into is not getting power there. And that plug runs I'm guessing from the driver side if the dash to the passenger side to plug up into the main engine harness.

Do you know which wire plugs from the dash plug to that pinout for the red and white injector?

 

http://www.gearhead-efi.com/Fuel-Inj...Information-42

Check out the wiring diagrams there. can you post a picture or two to show what youre talking about.

Did your 3.1 have VATS?

 

Yes, and it has power going to it!

 

try this: on your ecm harness connectors there are different pinouts. an AB connector and a CD connector. then each pin is numbered. the writing is small but its there on the ends. find pin A6. it should be a pink/black wire and run to your ECM 1 fuse. check that this is getting power. from the fuse the pink/black wire should go to your EVRV and EGR solenoid and also branch off to a red wire (INJ 1) and white wire (INJ 2)

Is any of this info correct? it should be but with mystery harness and ECM it could be off. Also check from your injectors the blue wire goes to pin D15/16 and the green goes to C15/D14.

 

Yes the ECM a6 pin is getting power
Blue d15 is not and green d14 is not!


And the red wire in the clearish plug (pin E) is for the red and white wires for the injector plugs, the white wire in the black plug is the one that matches with pin E, but it has no power to it, I'm going to try and trace it to it's start point and see what's missing!

 

I think I've narrowed it down to my VATS, I now have power to my fuel pump, and the red and white wires for the injectors that come on with the key! I'm just not getting any power to the blue and green wires for the injectors, and still no ALDL, and the car will not crank over! Would that be the vats because the truck harness I'm using doesn't have a wire for the vats pin. But I'm getting power to the vats fuse.

 

Okay so I was looking at my VATs and the started relay has already been bypassed, but now I'm not sure about the vats it's still hooked up, vats fuse has power, but I'm not getting a security light. And for the vats box only the orange wire has power, are any if the other wires for it suppose to have a power source. And what would that source be?

 

And all the sensors on the motor are getting power except for the coolant temp.

 

Okay, so I did some reading and looking up and the harness that I'm using turned out to be one from a 454tbi truck.