coolant overflow

[GreenGraffix]

Hey guys just want to see if I am on the right track here. I have a 76 280Z So here is my problem I got my car running for the year now. New plugs wires cap oil coolant so on and so forth. I had it running yesterday after getting the car in time 10 degrees. then I adjusted the AFM so the car was getting the right air fuel ratio. Now my coolant overflow tank started to squirt out of the top and the coolant was only luke warm. Temp gague was around 200.

So my question being is I should change the thermostat and the radaitor cap and go from there right? Oh and hope that it isnt the head gasket...

[zbane]

Compression check NOW!

I had a similar situation, and went the new thermostat/cap route.

Didn't solve a thing, and I ended up pretty much stranded with...a blown head gasket.

The reason for the overflow in my case (at least I think it to be the reason) was that the engine was pumping exhaust gas into the coolant line, thus causing the eruption of coolant...

[sblake01]

........then I adjusted the AFM so the car was getting the right air fuel ratio.

What did you use to read your AFM's air fuel ratio?

[GreenGraffix]

I know I did it the wrong way adjusting the AFM I used my ears to listen to the engine instead of a fancy tool. I adjusted the black wheel 4 theeth at a time till the engine ran good and had no skip to it after adjusting the time of the engine to 10 degrees. I was going off of http://www.atlanticz.ca/zclub/techtips/afm/index.html

[sblake01]

From the techtip you linked to:

Too Little Fuel (Lean Mixture) results in good gas mileage but hotter engine and pre-ignition in the intake "front fire".

Sometimes the use of a "fancy tool" is the only way to prevent misajustment which can lead to other problems. I wouldn't touch the AFM adjustment on either of my cars without my exhaust analyzer. These systems can be set way lean and still idle smooth so that's really not an indication of the air fuel ratio.

[GreenGraffix]

I did mark the black wheel good so I can put it back to where it was. Before I changed this the car was jumping 200-300 RPM's when at an idle like it was not getting enough gas+air and I know the timeing is right acording to the manual for manual trans. non-Cali. car settings.

[GreenGraffix]

Well between getting some new heater hose, replacing the thermostat, the radiatior cap, and sodering wires back onto the temp switch its good to go. Now to just get the few lights that dont work working and it should be ready to pass inspection for the year.

[GreenGraffix]

It passed inspection yesterday so I have been driving it around quite a bit today. I love my Z, so much fin to drive plus it will get better gas mileage then my dodge truck. Ahhh back to being a daily driver for the nice weather.