# Correct idle speed (z24)



## rowdy89 (Feb 6, 2010)

My 89 HB (stantran, z24) idles right up around 1800 rpms. On hot summer days, it will occasionally drop to around 900. I suspect a vacuum leak, but I checked everything within reach and pulled the codes (55...situation normal) didn't find anything out of place. Where should I look next?


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## minitrkingking (May 10, 2009)

If you let it idle high for about 30 seconds and give the gas pedal a good tap does it go away? If so, that is not a problem, my owner's manual says that it should do that normally as I thought I had an issue. hope that's the case for you


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## rowdy89 (Feb 6, 2010)

If I give it a tap or shift out of gear, the rpms drop to around 800-900 then go right back up again.


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## CMax03 (Jan 17, 2009)

Look at the heater flap system, or the pcv system I'm sure it 's an air leak break out the brake cleaner or stephscope with tube (listening for air leak)


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## SPEEDO (Jun 9, 2003)

High idle may be due to the thermo element or "wax kit", it push's on the choke cam.. (its located on the TB) Might check it out..


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## CMax03 (Jan 17, 2009)

ditto^^^^ set it to it's proper dimension or replace the thermo element assy.


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## rowdy89 (Feb 6, 2010)

Thanks for the input. I feel stupid, I just put 2 and 2 together and realized this might be a side effect of my engine running cold. The temp guage works fine, but the needle rarely gets much over the cold line. Maybe the thermostat is stuck open? Is this gonna cause any problems, other than wasting gas with that high idle?


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## SPEEDO (Jun 9, 2003)

check your coolant level and your temp sensor...
you have 2 (temp sensors) one has a injector style connector, that one feeds the ecu, the other one has a bullet style connector and it feeds the gauge


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## rowdy89 (Feb 6, 2010)

Coolant level is fine... how can I test the injector style sensor?


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## SPEEDO (Jun 9, 2003)

that one feeds the ecu, not the guage.
I wonder if you might have a air pocket where the temp sensor is not reading it right...


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## rowdy89 (Feb 6, 2010)

I think I'll pull out the thermostat this weekend and throw it in a pot of water on the stove. If I'm careful the womenfolk don't see me I can use the meat thermometer and figure out what temp it's opening at. The engine never really warms up. I can drive 50 miles, pop the hood and put my hand almost anywhere on it or the radiator. It gets really warm, not hot.


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## CMax03 (Jan 17, 2009)

Put a piece of cardboard in front of your radiator!


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