# 1987 D21 Hardboddy not passing 15mph test for no



## D21nissan4x4 (Mar 22, 2007)

Hello All,
I have being driven crazy with my truck not passing smog. 

I have check the EGR, BPT and all vacume lines. Checked fuel pressure is right at 36 PSI
shut the engine off holds for about 5 mins then slowly drops. 



Replaced the muffler for more back presure to drive the EGR system. EGR valve starts to pluse at or around 1550 RPM. INstalled new plugs. Here is my current test
Speed PRM %CO2 %O2 HC CO % NO
15 1776 13.80 0.72 115 .72 2382 G-PLUTER
25 2882 13.70 0.86 103 .71 869 PASS

I am not sure if the exhaust side is working right would this cause this problem.
If so how do i test.

Thank you,
Leroy


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## SPEEDO (Jun 9, 2003)

which engine??


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## D21nissan4x4 (Mar 22, 2007)

*z24i engine*

Hey,
It's the z24i engine 2.4L electronic injection TBI unit.

Help help help help anyone.
Thank you,
Leroy


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## dvdswanson (Nov 6, 2005)

have you check the PVC?


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## D21nissan4x4 (Mar 22, 2007)

*Don't have a PVC valve on mine*

Please if you come up with anything else let me know.
Thank you,
Leroy


dvdswanson said:


> have you check the PVC?


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## dvdswanson (Nov 6, 2005)

whats the NO for in the test, I forget.


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## SPEEDO (Jun 9, 2003)

any pinched,cracked or colapsed hoses???


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## smj999smj (Jan 1, 2006)

PCV is located just below the throttle body. All Nissans to my knowledge had PCV valves up until around 2002 or thereabouts.


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## bkea (Feb 4, 2005)

It def has a PCV valve. On the right side of and below the TBI (looking from in front of the truck.


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## D21nissan4x4 (Mar 22, 2007)

*Humm don't see it anywhere.*

Is this in the intake manifold or in the TBI unit? Because i don't see anything in alldata.com
or the service manual about the PVC valve on my 1987 4x4.

If did find it has one how would you test it? I will look for it tonight and get back to you guys.

Thank you for the help

leroy



bkea said:


> It def has a PCV valve. On the right side of and below the TBI (looking from in front of the truck.


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## 2ndb18 (Oct 24, 2004)

post your test again in columns i cant understand it


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## D21nissan4x4 (Mar 22, 2007)

*Reposting*

Hello All,
I have being driven crazy with my truck not passing smog.

I have check the EGR, BPT and all vacume lines. Checked fuel pressure is right at 36 PSI
shut the engine off holds for about 5 mins then slowly drops.



Replaced the muffler for more back presure to drive the EGR system. EGR valve starts to pluse at or around 
1550 RPM. INstalled new plugs. Here is my current test
Speed PRM %CO2 %O2 HC CO% NO
15 1776 13.80 0.72 115 .72 2382 G-PLUTER
25 2882 13.70 0.86 103 .71 869 PASS

I am not sure if the exhaust side is working right would this cause this problem.
If so how do i test.

Thank you,
Leroy



2ndb18 said:


> post your test again in columns i cant understand it


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## 88pathoffroad (Jun 6, 2004)

The EGR systems in these tend to collect a lot of soot and carbon. You may need to remove the EGR valve and the TBI and clean out the passages inside the intake to get it clean enough to work. Mine was completely plugged up when I got into it a while back. Simply spraying cleaner into the EGR won't do it. Thankfully, we don't have emissions here so I can just get away with deleting it altogether.


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## 87_D21_Z24i (Jun 17, 2007)

D21nissan4x4 said:


> Hello All,
> I have being driven crazy with my truck not passing smog.
> 
> I have check the EGR, BPT and all vacume lines. Checked fuel pressure is right at 36 PSI
> ...


Hi Leroy,
did you figure out what the cause for the high NoX (Nitrous Oxides) reading at 15 mph?
You must be located in Calif also. This is driving me crazy also. Locating emission parts for a 20 year old vehicle isn't so easy.
Although my truck failed the 15 mph test due to a very high NoX reading, everything else was good and the truck seems to run fine.

On my truck, the EGR tested okay with a vacuum pump (when applying a vacuum to it the EGR piston moves) but I found that it wasn't getting a vacuum signal between 1500 - 3000 rpm per the service manual spec.

Anyone know of a good source to buy Nissan emission parts for a 87 truck with a Z24i engine? 
I still need to locate a good AIV unit (Air Injection Valve)) which is located on the drivers side fender beneath the air filter intake hose. The vacuum dashpot, also referred to as a vacuum motor, for the AIV on my truck leaks so I need to find a replacement. No luck with the usual parts sources. 
If you have a good used one and other good parts you can part with I am interested.
Thanks

Dave


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