Mechanics

IDLE PROBLEMS

1991 Nissan 300ZX

1991 Nissan 300ZX 6 cyl Two Wheel Drive Automatic unknow miles

hello I have a 300zx with idle problem the past 2 months I have been having idles problem. I have replaced alot of stuff and can found out what it is. The parts that I have replaced is the fuel pump, fuel filter and fuel regulator, IACV, and all the hoses to it. I have replaced all spark plugs and yes they are factor. Both PVC values and the PVC hoses. All vacuum tubes. I have a data scan I can turn of each cylinder but you can tell that each cylinder is firing I have ohm tested injectors and coil packs and power tested the connectors I getting no fault codes. I can hear injectors ticking I have cleaned out intakes and air filters. This is whats happen the car takes along time to start after sitting for awhile I have to crank it 2 times to get it to start. Car drives fine has hesitation but its common with these cars car will idle fine but when I come to a complete stop it bogs down and surges and dies I have to put my foot on the gas to keep it idling if the car is costing in idle it will not stall but as soon as it stops it idles and bogs down and surges and slowly stalls. The funny thing is that as soon as I get where im going put it in park and feather the gas it will idle fine. It doesn't happen all the time but it happens alot
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Hardenstine
July 26, 2010.




Hi hardenstine, Welcome to 2carpros and TY for the donation

Lets start by cleaning out the EGR and PCV valves and test it, then test the throttle position sensor idle and WOT voltages and test the airflow meter/sensor, also test the coolant temperature sensor and a fuel pressure check

Tiny
Rasmataz
Jul 27, 2010.
Ok
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Tiny
Hardenstine
Jul 28, 2010.
Change the PCV valves and hose TPS has been test the fuel pressure good and MAF is reading great the temp sensor was also change out im not getting any codes evg is hard to get to so that is the only thing that I havent done the computer says it working im also smelling fuel coming from the tail pipe runs better when I turn the A/F base up all the way to 125 but will stall after turning on the a/c or putting in gear the the gas smell its worst

Tiny
Hardenstine
Aug 5, 2010.
Check and test the idle air control and auxillary air control valve and also the EGR valve. Also check for an idle up solenoid that increases the idle speed when the magnetic clutch engages the compressor to compensate for the load.

Tiny
Rasmataz
Aug 6, 2010.

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