[T3] ] Bad day at the (FI) office

Keith Park topnotch at nycap.rr.com
Thu Mar 24 17:54:33 PDT 2016


You shouldnt be stumped, its doing exactly what I would expect.

 

FIrst off, once again... the head temp resistor is for WARMUP CURVE ONLY,
you want under 100 ohms at running temp, way under 100 is fine.

 

Adjust the pressure sensor for main mixture, fuel pressure gives a fine
adjustment on that, with todays NYS winter blend E10 gas you will need to go
WAY richer than factory, if you running E15 DONT, thats much worse (Jim's
gonna smack me, but the AFR meter will tell you what is and should be).

 

SO:

 

adjust main mixture first, with head temp sensor stock (NO resistor) use
your MPS.

 

THEN, if you want to richen up the cold start, you add a SHUNT (parallel)
resistor to the head temp sensor to never let it get as high when cold.

 

Once your main mixture is right THEN we look into idle issues, and remember,
you may have fouled out the plugs when running too rich, this could be
causing some of the odd behavior.

 

Keith

 

For fun, when I got home, I checked the resistance of the temp sensor with
the resistor in place and it was 153 ohms. Without the resistor, it was 82
ohms. Clearly, my 100 ohm resistor is only giving about 70 ohms of
resistance. I know that Jim says the resistance number isn't that important
here, but 70 ohms made a huge difference in idle, drivability, and AFR.
Should this be so or does this point to another issue?

 

In any case, we're kind of back to where we were a month or so ago, with
three options:

 

-keep the resistor and lean out the mixture a bit at the MPS  (back towards
original calibration)

 

-remove the resistor and richen the mixture at the MPS (further away from
o.c.)

 

-remove the resistor, return MPS to o.c., and do something else that I'm
unsure of. I'd have to do something though because if removing the resistor
made it as lean as it did today, then recalibrating the MPS to original
would make it even more so as original is clockwise from where I am now. 

 

I'm definitely stumped!

 

 

 

Topnotch Restorations

topnotch at nycap.rr.com

http://www.a383ina68.addr.com/radiorest/main.htm

71 Squareback  "Hothe"
65 Notchback  "El Baja Rojo"

93 RX7  "Redstur"

87 Golf  "Winterat"

 

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