I have a 92 Camaro with a 305 TBI, I am wanting to swap in a carbed 350. How do I get my electric gauges such as the speedometer which runs off a VSS, to the ECU, then to the cluster? Or any other electrical gauge to work once I swap in the carbed 350? Thanks.

 

It all works fine - just don't go cutting any wires on the driver side harness and you'll be good. The pass side harness is all the sensor/computer wires. Don't cut any wires - just tuck all the pass side wires into the fenderwell and leave them alone until the car runs well and everything - 4 years later my wires are still tucked in there - sometimes I use one for an easy cabin-to-exterior connection (like fog lights, TC lockup, exterior lighting, etc.).

 

Ok, so you're saying to leave in the ECU and leave the engine harness in the car? Just unhook what you don't need, but keep the sensors and everything that runs the cluster plugged in and it will all be fine? Tuck the rest of the harness behind the fenders and call it done?

 

Basically. You can remove the ECM. The pass side wiring is all the sensors for the ECM, so all that wiring will get tucked aside. There's a couple wires that run from pass harness to driver side in the loom behind the engine - things like fuel pump relay wire and fan switch wire to fan relay - fish those out then you can bundle all thye rest and tuck it all in the fenderwell. All gauges will work fine.

You have tach - gets signal from the dist.
Volts - gets signal from a mystery place (trust me, it still works fine - I just don't know exactly what wire from alternator feeds it)
gas - that comes from tank
oil pressure - that comes from your OPSU right above the oil filter
water temp - that comes from sender in driver head between #1 & #3 spark plug.

I highly recommend ditching the stock relay and fan switch, and using an aftermarket seperate fan controller - I run a Flex-a-lite and it's the best $100 I ever spent.

Then, after the swap, you'll have alot of already installed wires to make use of, like for manual fan switches, fog lights, exterior lighting, manual TC lockup, etc. I use my old ECM wires alot - thus I never yanked them out - they tuck away totally hidden and I always have p-lenty of wires already nicely sealed between the cabin and the outside.

PS - if you leave the ECM inj the car, you'll always have a SES light. If you remove the ECM, no light.

 

I was wondering if all the other gauges had their own sending units/sensors. I was not sure if they all went through the ECM first or not. That is good to know then, and what fan was it you used? I was going to use my stock fan and install one of those switches that kicked the fan on at 200* and shut off at 185*. Chances are the 350 I'm swapping in will be an older 350 out of a truck and I think it will have a fan that stays on while the motor is running anyways. Bad idea?

 

I used my stock single TBI fan, and kept my stock radiator. The Flex-a-lite controller I used probes the radiator for temp (between the fins), and it fully adjustable. It turns my fan on a 65% full power for 2 minutes, then full power after if still needed (reduces immediate high amperage draw on the elctrical system). I can adjust the temp, so in summer I turn it down a tad, and winter turn it up a tad (that way I'm a little cooler in hot summer months, and I get a little better heat from the vents in the cold winter months). Then, it also has a manual on switch, so I can turn it on anytime I like - I use that when entering the drive-thru line in the summer, or when I'm parking for a minute but leaving engine running. This controller keeps my warm-natured 350 plenty cool - I never see over 200 even in the hottest summer 100 degree+ day.

If your 350 has a manual clutch fan setup on it, I'd remove it - without having the proper shrouding around the radiator, it just won't do nearly as well as your stock electric fan will. Those manual fans usually are just a part of the water pump pulley, and come right off.

 

Very nice, I see you can buy a lot of Flex-a-Lite products off of Summitracing.com but what exactly did you buy and install? If you could give a part # that would be awesome.

 

Is this the one?

http://www.summitracing.com/parts/FLX-31147/

 

I'm using this one.

http://www.summitracing.com/parts/HDA-3651/

It includes a relay. I put the probe on the block next to the water pump.

 

So you just have the probe laying next to the water pump? How is it taking an accurate temp to know to come on at the right time?

 

This is the one I'm using - expensive at $90, but it's really great. Has provisions for a manual on switch, does the 65% initial on to reduce electrical load, will run single or dual fans, works with A/C, and fully adjustable temps from 160 - 240F.

http://www.summitracing.com/parts/FLX-31149

This one needs no relay, comes with everything needed (except a switch for manual on option - you can use any switch for that). The radiator probe goes between the fins, not "through" the radiator - thus no leakage issues.

MGM-RS has a different type - it comes with a threaded sensor that he has installed in the block itself, not just 'laying' against it.

 

How does it install into the block?

 

It's threaded, just screws in - anywhere there is a coolant passage (like the stock location for the fan switch pass side head). I personally have no idea where exactly MGM RS has his installed.

I'm hoping some day to see his car on my way to the beach! I was planning to go to Rims on the River this weekend, but threat of rain means I won't spend the $50 in gas to do it.

MGM RS ... are you doing Rims on the River this weekend?

 

I work 7am-4pm on Saturday but I'll try to take the day off. At the worst, I won't make it to downtown until 5pm. My Camaro runs good though. It's my daily driver.

 

Well, don't take off on my account - I'm not going - too much chance of rain! One of these days I'll be in your neck of the woods, and we'll hook up for lunch or something.