# 86.5 Hardbody Idle Problems.



## JesseB. (Oct 29, 2005)

Hello, my d21 is idiling high, (2000)rpm's... 
I looked around and on the passenger side of the carb, there
is a plug (black with the word "press") that is no longer connected.. 
It's below the throttle cable, and below the fuel line.. 
It's no longer connected because the "leads from the switch or part, 
have rusted and it looks like they have broke off into the female end
that goes to the wiring harness... 
A) what is the name of this switch or relay... 
B) where can I find a replacement besides the dealership
C) is there any way to "fool" the switch, (in other words, shorting 
the two leads together to make the computer think the switch is working)... 
( I know this is not usually done, but I know the switch is good, it just has 
the two leads broken off of it..)


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## JesseB. (Oct 29, 2005)

*No Help Yet...*

I have determined the plug I was talking about goes to the (Heater Mixture).. 
I tied the two wires together and POOF.. smoke.. 
Don't tie the wires together... 

Since the plug ends broke off. I took a drill, drilled out the insulation around the plug
that is under the carb...sodered to (pigtails) back where the old wires were... 
Still won't idle down.. 
I'm thinking that when I shorted the wires together, I took out the Heater Mixture Relay.. 
Where can I find a new one?
Or, if I go to the junkyard will any nissan car in this age range have the same relay?

Thanks, Jesse.....


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## SPEEDO (Jun 9, 2003)

your high idle is probably from the "wax kit" that went bad, its on the front of the throttlebody, should have a water hose going to it...
mine went out and thats what it was...


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## 88pathoffroad (Jun 6, 2004)

Damn man, don't cross wires wondering what they do. Next time it could be your ECU and you'd have to find another one.

The mixture heater is notorious for shorting out. I've since gutted the center of mine and left it unplugged. Still runs fine, a little tough to start on cold days though.


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## JesseB. (Oct 29, 2005)

Damn man, don't cross wires wondering what they do. Next time it could be your ECU and you'd have to find another one.

I couldn't agree with you more... 
Still have the High Idle Problem... 
You know this engine.. Tell me how to Fix the Damn Thing.. 
I love this truck, but after the Clutch, and the Tranny...
I think I'm going mad... 
I must get this thing mechanically right or I'll have to replace with a 
90's model Pathfinder... 
(That I'll have the same damn problems with).. 

PS.. Tried to idle it down with the Idle screw.. To No Avail........... 
It's got to be this mixture heater plug.. Or the CPU is telling the Choke to stay on.. 

Help a Nissan Brother Out... 
Idiling High In Lubbock, TX... JB..........


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## SPEEDO (Jun 9, 2003)

try this part(Nissan) number (I had to replace mine) 16391-12G00 they call it a thermo or wax kit, when you get it, its in a spring contraption (keeps it compressed) that makes it look pretty strange...


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## 88pathoffroad (Jun 6, 2004)

The wax choke could be causing the problem, that's the little plunger-looking thing on front of the TBI with two small coolant hoses feeding it. I've taken mine apart and cleaned it out, shot it with a little WD-40 and it worked fine after.


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## JesseB. (Oct 29, 2005)

"I've taken mine apart and cleaned it out, shot it with a little WD-40 and it worked fine after." 

Sounds like a GREAT IDEA.... Something that dosen't cost anything to repair.. 
I'll give it the B-12 Chemtool and the WD 40 trick and see If this helps... 
I just hope its easy to remove and clean.. 

It really does act like a "stuck choke".. 
This thing has always "Idled high until it "warmed up" and then always went 
down to operating Idle".. Now it won't come off of 2000rpm's and with gas 
prices at $3.00 per gallon, I need this thing to Idle low, every chance it gets.. 
Other than the high Idle, its running Fine..... 

If anyone has any other ideas why this thing is Idiling high.. 
Let me know..


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## bkea (Feb 4, 2005)

JesseB. said:


> "I've taken mine apart and cleaned it out, shot it with a little WD-40 and it worked fine after."
> 
> Sounds like a GREAT IDEA.... Something that dosen't cost anything to repair..
> I'll give it the B-12 Chemtool and the WD 40 trick and see If this helps...
> ...


I say you need to replace the wax thermo pellet. They cost about $65. Mine was doing similar until I replaced it.


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## JesseB. (Oct 29, 2005)

*Still Not Working.*

Removed the thermo element, took it apart, cleaned it and it still wouldn't work.. 
Time for pan B... 

where can I find a repalacement part... For the Cheapest Price?/ 

I need a wax kit..aka, Thermo element. 

Thanks, Jesse...


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## NOWEFG (Nov 19, 2008)

Found TBI info for Sentra's at SE-R.net that may apply; suggesting that high idle can be caused by dirty/stuck FICD and Idle-up solenoids. Makes sense, especially if the mechanical fast idle indicates normal, but the idle is still way high. So it may not be the computer, just a solenoid or sensor.


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