So, if you haven't seen my other posts, I have an 88 firebird that had a 2.8, I put in a 305 tbi and it turns out the motor won't run. It has the donor tbi wiring harness and ecm. I'm putting in a carbed 305. When I do this, I know I need to get hei distributer, tranny torque lock up kit, and remove elect. Fuel pump and put in hose for mechanical fuel pump to run right. My questions are once I put in the carbed motor, can I completely remove the ecm and harness all the way to the firewall and still have working gauges, and working heater, lights, etc? Please help, thank you.

 

yes, the gauge wires run through the driver side fire wall along with the starter wiring and the light wiring. The ecm wiring can be removed along with the knock sensor 02 sensor most of the relays on the drivers side.

 

So that means I can remove ecm and all of that wiring all the way up to the firewall, correct? What other small things should I pay attention to here? Thanks for the help

 

Yes, I just did this to my 84 camaro and all works well. Not much really, the ecm harness conects to an oil pressure sensor mine had two one for the ecm and one for he gauge. Now if the car has an automatic transmission youll have to get something to lock up the torque converter mine is a 5 speed so i didnt have to do that.

 

Thank you. So, my firebird has both the guages and the dash lights, when i plug in the sensors from the camaro to the firewall plug in on the ddrivers side, will the lights work as well as the guages? Im not sure but i think that the camaro only had the guages, though i could be wrong.

 

The llights on your gauges? Like the warning lights and what not? no the only one that wors on mine is the parking brake the check engine and electric chock light dosnet work any more.

 

Thank you all for the help, now which torque converter lock up kit do I get? Because it has an electric speedo, also I think I cut the wires for that by accident when removing extra wires from ecm

 

No problem, this is were I'm unsure since I have a 5 speed and a mechanical speedo but i found a youtube video about

 

Thank you all so much for the help! I bought a lock up kit from jegs, and am waiting for it in the mail, in the meantime, I have a couple of issues, the fuel gauge reads past full which I was told its because it isnt grounded. I checked and it seems there isnt even power going to it. Why would that be? also, the temp gauge wont work, but I hooked up the grren wire to the sensor, what else could it be? because doesnt that run right to the dash?

 

No problem and id say check the ground on the motor. on my car coming off the negative cable thers a small wire going to the fender and a larger wire connecting to the front of the engine block on the back of the head on the passanger side there is a ground for the engine harness and a ground strap going front the back of the head to the fire wall. After you check that you can see if they come back if the temp sensor dosent you can check the sensor its self I had a factory gauge go out on me.

 

Fuel level sender does not require voltage to work. It sends a ohm signal back to the gauge which interprets the signal into a visable readout on the gauge. The gauge uses power to operate. 3 wires go into the gas tank if it originally had a intank fuel pump. One is a power for the pump, the other is a ground, the other is the signal wire from the fuel level sender. Just like if u ground the oil pressure sender wire the gauge will read 60psi or 0psi can't remember. My fuel level reads past Full when I have a full tank. It's the ohm reading and the gauge and how it's setup, so it reads alittle high but remember that when your tank is low lol. If u ground the wire for the fuel level sensor you should see the fuel gauge move. If it does then the sender and gauge are working correctly. If u put a meter on the fuel level sensor you should see a ohm change as the arm moves up and down. You need power to the gauge, the gauge working correctly and the fuel level sensor working to get it all to work correctly. If one is not working then none work. Once u verify its not working then you deduce the problem to find the answer.

If the sensor is not working u will not get any ohm difference out of the wire going to the gauge as the arm moves. If u get different readings then move on to the gauge, verify it has power, if it does then check the connections at the gauge. If still nothing then it's probably the gauge. Grounding the fuel Level wire at the tank you should see a drastic change in the fuel level needle and that would be the quickest way to verify gauge operation. Since u can't move the fuel level arm when it's installed u can remove or add fuel to the tank to verify its working and moving the fuel level arm.

Cooling gauge uses a seperate sensor than the fan switch, u need to verify your using the right one. The one in the head by the exhaust is for the fan and is also a single wire but it's a clip on connector, gauge temp sender uses a spade type connector and I think it's located in the intake or driver head... Been so long since mine was stock lol.

A quick educational Note for you... Any gauge that uses a single wire hookup does not use power to operate. It's a resistance/ohm type sender and it's usually grounded through its case into whatever it screws into. You have to be careful using Teflon tape as it can insulate the threads and not allow it to ground. 2 and 3 wire sensors have grounding and powering wires but they are newer more modern tech and not on our classic cars.

 

Thank you for all the advise, it was very informational. I will try it next time I go to the garage. But a question I have before I get into it, if the sensor tests good, but the gauge still doesn't read, where does the power come from for that gauge? If it's the ecm do you know which wire to bypass? Because the ecm is not hooked up to much anymore besides AC and a few other things. I can't thank you enough for all the other help

 

ECM doesn't control any gauges but tach and speedo I think, but prob not the speedo now that I think about it.

Gauge power comes from 2 plugs at the back of the instrument cluster which slides into the copper laminated gauge backing with the printed circuit board. Power comes from the inside fuse panel and I think it's a 10amp fuse. This is with firebird as that's all I'm familiar with.