Low Idle (Near Stall)
08-13-2018, 12:26 PM
#1
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Join Date: Feb 2017
Posts: 12
Low Idle (Near Stall)
Hey everyone, when starting (cold) the 300zx (1987 Turbo) the idle is around 600 - 700, then it start dropping and sometimes even jumping at the 500 - 450 line like it's about to stall.
I'm curious why this is happening. Should I try and adjust the RPM? When in drive it sits at around 500.
Another thing, when starting the car it sometimes doesn't even start. I really gotta crank it for a good 2 seconds. I think it could be related. Thanks!
I'm curious why this is happening. Should I try and adjust the RPM? When in drive it sits at around 500.
Another thing, when starting the car it sometimes doesn't even start. I really gotta crank it for a good 2 seconds. I think it could be related. Thanks!
08-14-2018, 07:28 PM
#3
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Join Date: Feb 2017
Posts: 12
I'm thinking this may also have something to do with the vac lines since the car does have trouble starting up.
08-14-2018, 07:50 PM
#4
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Join Date: May 2010
Location: Orlando, FL
Posts: 114
The IAC valve , next to the EGR valve may be stuck close. When it’s cold you should be able to blow through it. When it warms it closes. That was one of the issues with mine, 89T. I put a used one on but thinking about getting a new one.
I’d like to also clean my MAF as well. Mine starts right up idles good and about 30secs in does what yours does. I have to keep anout 1100rpm until it warms up or just get in and go.
I’d like to also clean my MAF as well. Mine starts right up idles good and about 30secs in does what yours does. I have to keep anout 1100rpm until it warms up or just get in and go.
Last edited by JSM; 08-14-2018 at 08:18 PM.
08-14-2018, 08:05 PM
#5
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Join Date: Feb 2017
Posts: 12
The IAC valve , next to the EGR valve may be stuck close. When it’s cold you should be able to blow through it. When it warms it closes. That was one of the issues with mine, 89T. I put a used one on but thinking about getting a new one.
I’d like to also clean my MAF as well. Mine starts right up idles good and about 30secs in does what yours does. Butit takes 2min or so. I have to keep anout 1100rpm until it warms up or just get in and go.
I’d like to also clean my MAF as well. Mine starts right up idles good and about 30secs in does what yours does. Butit takes 2min or so. I have to keep anout 1100rpm until it warms up or just get in and go.
08-15-2018, 12:25 PM
#6
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Join Date: May 2010
Location: Orlando, FL
Posts: 114
No I would not increase the idle . I’m assuming once it warms your idle is fine? If you increase it, when it warms it will likely be even higher.
If it idles low low once warm too I would investigate your vacuum lines. Also check timing and general tune up first. Plugs, cap, wires, rotor etc.
If it idles low low once warm too I would investigate your vacuum lines. Also check timing and general tune up first. Plugs, cap, wires, rotor etc.
08-18-2018, 06:15 PM
#7
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Join Date: Nov 2013
Location: east KS
Posts: 300
Very easy to clean the throttle remove the intake tube open the throttle fully ( off)
spray carb spray on a blue p towel ,tooth brush and clean where the plate hits the housing
you can try jumping the idle air controller
my 86t has a idle swt. That needs to connect
87 likely a tps , that needs to be set right too
spray carb spray on a blue p towel ,tooth brush and clean where the plate hits the housing
you can try jumping the idle air controller
my 86t has a idle swt. That needs to connect
87 likely a tps , that needs to be set right too
Last edited by 86tcoupe; 08-18-2018 at 06:20 PM.
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