I don't think that there are very many of us who have given much effort to experimenting with the ECM. Mostly we try to keep the system running until a Pony, Toyota or Weber carburetor falls into one's lap. Or one makes the jump to EFI during a 1.6 conversion.

I imagine the coolant temp sensor helps the ECM control the fuel mix and maybe the ignition. This assumes that you are using the Hitachi carburetor. I know that sounds a bit obvious, but It is the best I can do. I am amazed that you haven't had problems with it being disconnected...

/ubbthreads/images/graemlins/thud.gif

 

I'm not sure what it does, but you would be amazed at all the stuff I have disconnected on mine!! It was running crappy one day, and I decided I would just pull stuff off until it ran better. All that's left is the wires that go to the distributor, the temp gauge wire, and the wires to the carb...but I have run it for weeks on end with the carb unplugged /ubbthreads/images/graemlins/neener.gif

 

It tells the ecm the temp of the engine and then in turns adjusts the fuel mixture and in some vehicles ignition. If the temp gauge is bad and it's saying that the temp is cooler than it is you'll get bad gas milage.

 

I've got a whole box of those, pm me if you want a good one.
Sarge

 

For more information on disabling all the extraneous crap on the stock carburetor check out this thread:
http://bbs.off-road.com/ubbthreads/showf...rue#Post1084953
freebird01

Mel

 

My mileage has not been very good for quite awhile, but I
attributed that to 32s with the GRS II and stock ratio in the diffs. I still get 22 - 25 on the road.
Guess I should replace the gizmo /ubbthreads/images/graemlins/cussing.gif

 

Thanks for the sensor Sarge. I got it installed Fri and ran around quite abit on Sat. The revs seem to even out quite abit quicker when it is cold and the rpms stay up better when going up a long hill. Let you know if the mileage is affected at all.

 

Thanks for buying lunch /ubbthreads/images/graemlins/smile.gif
I went through 6 before finding one that would test out good consistently. I'm amazed as old as these things are half of that stuff still works...
Sarge

 

Sarge,
Finally got some mileage on the Zuk after replacing the sensor. Moab trip was a wash because the wind was so damn bad getting out there. I probably averaged 50 MPH, according to my GPS.
Around town, I'm getting about 3 - 4 miles better per gallon and probably 5 - 6 on the road.
So, I would definitely advise Zukers to check the condition of that sensor.
Thanks again - Neale

 

No problem . These things are a an issue with anything of that age , efi stuff is even worse .
Sarge