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Old 01-11-2009, 09:01 PM
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Can I eliminate the ECU from the engine completely now?

In my 86 Camaro, with the 350 carbureted SBC swap, ignition is HEI w/ vacuum advance. Mechanical fuel pump, and the gauges are all mechanical as well minus the new temp gauge which isn't installed yet. The cars a 5 speed, and has 1 air bag I think but that's going bye bye. The smog crap is gone, the A/C has been eliminated, there is no EGR system. The fan is on with the key, so I'm guessing that's wired to an accessory and not the ECU.

Yet the engine bay still has a harness, that has about 15 connections leading to NOTHING and it's really getting to me. I can't seem to figure out if this engine swap has completely eliminated the need for the stock ECU or not, the temp sensor which is screwed into the front of the intake manifold is still plugged in. There are also a couple of wires grounded to the water neck coming out of the harness. Above the oil filter there is a sensor, which is just screwed into the block not doing anything with no wires to it, but it isn't the oil pressure because that gauge works perfectly fine.

Does anybody know if I can eliminate the harness from the engine bay along with the ECU where ever it's hiding or is that temp sensor on the intake manifold possibly still helping run my engine? If so.. how?

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Old 01-11-2009, 09:07 PM
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You could try just unhooking it and see. My swap in my Fiero still has the Computer, its just one big butt connector now. I plan on removing it one day but its not out in the open so I haven't been worried about it.
I did cut all of the unused wires at the harness but wish I had left a few of them, they are nice because you can reuse them for other things later and don't have to add more holes to your firewall.
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Old 01-12-2009, 03:34 AM
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start the engine and unplug it . the temp senor shouldnt be have anything to do with the engine runing.when i did my swap i took out about 75ft of unused wire. on the fire wall u should have 2 plugs one for the acess, ( lights, horn etc.) the other plug u should only need like 4 or 5 wires. dist, , key, alt, starter, the other mess of wires go back into the dash on the p****enger side to the ecu. 86 those. go to a salvage yrd and check out a old 60's car or truck look at the wire harness, thats all u need to make your car run.
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Old 01-12-2009, 06:22 AM
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When I went to an Airgap/Demon carb and regular HEI I cut that computer harness right out.
I cut it where it leaves the passenger compartment inside the front pass.
fender at the bottom.
You can also remove the computer, its behind the dash pass. side, you get to it from below.
You can also rid yourself of the harness where it goes out of the pass. compartment behind the kick panel.
If you donīt want to get behind the fender cut it where it leaves the engine compartment, at the heater blower motor.

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Old 01-12-2009, 07:58 AM
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Alright, that's the exact harness I'm talking about, the one you have posted Malc, all those connections are burning on my engine and I'm going to remove it now since I see I don't need them. One main harness comes from the drivers side, and another from the passenger side, the radiator fan I won't cut but the rest I can just snip and tape off I guess?

What is your temperature sensor hooked up to? It appears that you actually have 2 temp sensors?

Also, I have a lot of unplugged sensors in the drivers side of the engine bay, right next to where the A/C line used to be. Did they plug into the A/C system or are there a bunch of empty connectors on your car at that point too?


I just realized there's a sensor plugged into the drivers side head between cylinder 1&3 I thought it was knock but it's in the head so I guess that's another temp sensor? Can I unhook that too since my dash gauge doesn't even work?

Sorry for so many Q's I just want to make sure I do this once and do it right!

_ Brett

Last edited by 5_speed; 01-12-2009 at 08:06 AM.
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Old 01-12-2009, 08:38 AM
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The sensor between 1 and 3 is your temp gauge, mine is now on the right of my intake, the other is the electric fan switch.
Your knock sensor is on the engine block pass. side just above the oil pan rail,
thatīll be redundant too.


Also, I have a lot of unplugged sensors in the drivers side of the engine bay, right next to where the A/C line used to be. Did they plug into the A/C system or are there a bunch of empty connectors on your car at that point too?
The A/C stuff is on the pass. side not the driverīs side.

If you have this stuff on the driverīs side firewall you can eliminate those too,
I just cut the wires and taped off the ends.

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Old 01-12-2009, 08:53 AM
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This is the little bundle of nothingness, my temp gauge doesn't even work anyway and my fan is always on, so I should just start getting wire cutter happy in there!

I need to install my new temp gauge sender, I bought a fitting that fits the front of the intake manifold but if I can screw it into the head that would be ideal because it will be more hidden.
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Old 01-12-2009, 09:05 AM
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I had a connection in the area your yellow arrow is pointing and that was for the power steering.
Aparently it gave more aid at low speeds and "tightened" up on the freeway.
More shots of my engine bay.
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Old 01-12-2009, 09:20 AM
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Even better I'm eliminating the power steering in favor of a manual box from an S-10.

Thanks for the photos, I'm nervous but I'm sure once I start cutting and the engine is still running I'll feel much better!

Your bay looks great now though great job!
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Old 01-13-2009, 12:24 AM
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"I need to install my new temp gauge sender, I bought a fitting that fits the front of the intake manifold but if I can screw it into the head that would be ideal because it will be more hidden."

I placed my temp sender in the manifold because in the head it interferred
when removing spark plugs, same with the fan switch, located at the rear of the other head.
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Old 01-18-2009, 10:30 AM
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A little late, but your coolant temp sending unit needs to be in the intake near the thermostat housing to give you the best reading. It needs to be covered with coolant to be accurate and if you can get to the coolant in the head, your reading is still going to be influenced too much from the near by combustion process.

Trees
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