Hello,
I know many have had this problem in the past, even I have had it several times over 17 years of driving this car.
The car will stall right after start up on the first attempt. Then it will start okay on the second attempt. Then once the car is warmed up, the idle will start to fluctuate between 800 and maybe 400 when sitting at a traffic light. It is also prone to the idle dropping completely off and stalling on deceleration.
Anyways, I am trying to get this solved ASAP without throwing parts at the problem. I have checked all vacuum lines and replaced any that looked suspect. I also purchased a new Idle Air Adjusting (IAA) Unit from Nissan, but when I applied voltage to the old one, it seemed to operate. For those that may not know, the IAA unit assembly is made up of two Idle Air Control Valves (IACV), the FICD and the AAV. I did notice that the resistance on the connectors of the old valve assembly was higher on the FICD valve of old the assembly by 30 ohms. The resistance on the AAV valve was about the same.
I will replace the IAA unit anyways since I have purchased it, but wanted to know if anyone had any other ideas. Could it be the MAF needs to be cleaned?
All helps is appreciated.
Idle Problem
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Hijacker
- Posts: 14373
- Joined: Wed Aug 13, 2003 4:57 am
- Car: '92 240sx Convertible
'94 F-150 - Location: Fredericksburg, VA
Re: Idle Problem
MAF and O2 sensor come to mind.
Re: Idle Problem
Well hopefully I can just clean the MAF because those are pretty expensive. I will pick up some MAF cleaner on the way home. The O2 sensor is only a couple of months old.
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biggie
- Moderator
- Posts: 8302
- Joined: Wed Jul 24, 2002 2:31 am
- Car: '16 Q70L/'14 Q60S Vert/'19 Armada/'09 FX35
- Location: Clemmons, NC
Re: Idle Problem
Used MAF wouldn't be too expensive, I've got a couple laying around.
One other possibiility would be the Temp sensor that goes to the ECU, could be bad and need replacing.
One other possibiility would be the Temp sensor that goes to the ECU, could be bad and need replacing.
Re: Idle Problem
both 240's ive had started with this problem.
the first, eventualy progressed into a mis-fire, with the replacement of the wires, dist. cap, sparks, & dist rotor the issue went away.
the second was simply a mis timing, by loosing the dist. bolts & messing with the timing back and forth a bit i was able to find a timing that worked.
other than my personal experience ive heard of the idle air control valve also causing a similair problem. im not sure when the last time you replaced your sparks, wires, dist. cap, & rotor was but thats always good preventive matnience anyways lol
hopefully this helps :]
the first, eventualy progressed into a mis-fire, with the replacement of the wires, dist. cap, sparks, & dist rotor the issue went away.
the second was simply a mis timing, by loosing the dist. bolts & messing with the timing back and forth a bit i was able to find a timing that worked.
other than my personal experience ive heard of the idle air control valve also causing a similair problem. im not sure when the last time you replaced your sparks, wires, dist. cap, & rotor was but thats always good preventive matnience anyways lol
hopefully this helps :]
Re: Idle Problem
I am going to start by cleaning the MAF and go from there. I have never replaced the spark plug wires, but have replaced the cap and rotor may 10+ years ago. lol, but the car runs great other than the idle problem. I do change spark plugs annually
Re: Idle Problem
Looks like replacing the IAA unit and cleaning the MAF with the special MAF cleaner resolved the problem. I also noticed a pin hole leak in the hose going from the fuel filter into the injector rail. I guess this could have caused the idle problem also. Fortunately I was able to cut off the part of the hose with the leak and reattach to filter. That hose is $0.75 - $1.09/inch from the dealership. Anyways it seems to be idling okay for now.