# '86 Nissan 300ZX, Non-Turbo



## Layla56 (Feb 28, 2005)

Gotta question and I hope somebody here can help me.

When we start the car, the rpms are high, then suddenly the car starts to sputter and the rpms drop dramatically. Car also sputters in drive.

Is there anyone out there who can tell me what might be the cause of this problem? I would appreciate any and all suggestions - and thanks a whole big bunch for your replies!


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## JAMESZ (Mar 12, 2004)

Do a tune up. New plugs, cap, rotor, fuel filter, air filter, plug wires, and if due timing belt. If that doesn't fix it it will most likely be the MAF. Also do a leak down test and make sure compression is still good.


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## Zen31ZR (Mar 24, 2004)

Could be any number of things, unfortunately. 2 components that directly affect airflow into the engine when it is first started are the air control valve on the passenger side of the intake manifold, and the IAC control on the driver side of the intake manifold. Make sure the hoses are properly connected to the ports on those, a loose or missing hose will let in unmetered air and cause the problem you describe..... 
Does this problem disappear or continue after the engine is completely warmed up? 
You may also wish to look into doing a tuneup, if you haven't done one recently. Regular maintenance can cure a multitude of evils......


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## Layla56 (Feb 28, 2005)

Wow, thanks so much for your replies! The cap, rotor, plugs, and plug wires have already been replaced and are brand new. Will look into the air filters.

To answer Zen's question, when the car is warmed up and driven, it does fine. However, when idle, it's not doing too well. The rpms are between 500-700, and were normally at about 1200.

New question - is the "MAF" the Mass AirFlow Sensor????

Thanks again, I appreciate it!


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## JAMESZ (Mar 12, 2004)

Layla56 said:


> New question - is the "MAF" the Mass AirFlow Sensor????


Yes. Also vacuum hoses. Zen had some good points too.


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## Layla56 (Feb 28, 2005)

About the timing:

My brother put a timing light on the car and he can't see any timing marks. Would this mean that the timing belt has slipped or needs replacement?

PS: You guys are great, lots of insight to someone who knows "nuttin'."


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## Domdogg123 (Nov 12, 2004)

Layla56 said:


> About the timing:
> 
> My brother put a timing light on the car and he can't see any timing marks. Would this mean that the timing belt has slipped or needs replacement?
> 
> PS: You guys are great, lots of insight to someone who knows "nuttin'."


look at your crank and see all of those notches? those are the timing marks. Use some white out and mark the one which yours should be at (sticker under hood). Then use the timing light to flash it.


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## Zen31ZR (Mar 24, 2004)

Layla56 said:


> Wow, thanks so much for your replies! The cap, rotor, plugs, and plug wires have already been replaced and are brand new. Will look into the air filters.
> 
> To answer Zen's question, when the car is warmed up and driven, it does fine. However, when idle, it's not doing too well. The rpms are between 500-700, and were normally at about 1200.
> 
> ...


The VG30 typically idles at 500-700 rpm. It's a touch lumpy, but it idles there just fine. Or, it should if everything was working properly.


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## Zen31ZR (Mar 24, 2004)

Layla56 said:


> About the timing:
> 
> My brother put a timing light on the car and he can't see any timing marks. Would this mean that the timing belt has slipped or needs replacement?
> 
> PS: You guys are great, lots of insight to someone who knows "nuttin'."


Could be the distributor is _way_ out of time. 40 degrees or so on either side would put it out of sight of the timing light. 
While you're here, I would recommend downloading the FSM located in the stickies.


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## jbraun (Mar 2, 2005)

my car has a similar problem however i do not think it is the timing because it revs easily and the problem goes away after the engine is warmed up.


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## Zen31ZR (Mar 24, 2004)

jbraun said:


> my car has a similar problem however i do not think it is the timing because it revs easily and the problem goes away after the engine is warmed up.


That is likely either of the 2 original things I mentioned. Either the IAC on the driver side or the other air control unit on the passenger side. If either one is slow to react or gets stuck in one position, the car will idle like crap. You may also wish to run the ECU diagnostics, could be a bad coolant temp sensor as well..


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## kutrecords2005 (Mar 4, 2005)

Layla56 said:


> Gotta question and I hope somebody here can help me.
> 
> When we start the car, the rpms are high, then suddenly the car starts to sputter and the rpms drop dramatically. Car also sputters in drive.
> 
> Is there anyone out there who can tell me what might be the cause of this problem? I would appreciate any and all suggestions - and thanks a whole big bunch for your replies!


could be a feul delivery prob check/ the filter check the regulator and pump


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