Weird 1996 fuel injectors

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scottgas
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Car: 1996 Nissan 300ZX N/A steel roof

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This is on my son's '96 ns base model. We are sorting through running/idle issues and have gotten to replacing injectors. I found what should be the correct injectors on Amazon and we ordered them. What we got are indeed red late style injectors. Our issue is his car does NOT have the "normal" late style injectors. His car has the shorter early style injectors BUT with the late style connectors. This car was purchased out of California and I believe it was originally titled in California. Did '96 model California emission cars get some kind of weird 1 year only injector or did ALL California cars get different injectors. His production date is 9/95. I just messaged Z1 for help also.

I just looked on Rockauto.com and they actually list 2 injectors for '96 na models. 1 is the normal red late style injector. The other is just as I described above, shorter early style BUT with late connectors. I can easily order these from Rockauto BUT my concern is modern ethanol eats up early injectors (from what I have read here) and I don't want to install new early injectors and have issues down the road. This HAS NOT been a fun job by ANY means. I would rather just update if need be.


scottgas
Posts: 176
Joined: Sat Aug 10, 2019 11:20 am
Car: 1996 Nissan 300ZX N/A steel roof

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OK, looking at the injectors again, old style looking injectors that came out of the car look that same as the late style ones at the bottom of the injectors where the fuel sprays out BUT the old ones that came out of the car don't have the wide black area above the screen like new ones

scottgas
Posts: 176
Joined: Sat Aug 10, 2019 11:20 am
Car: 1996 Nissan 300ZX N/A steel roof

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https://www.rockauto.com/en/moreinfo.ph ... 24&jsn=380
The above is what we purchased.
The below is what came out of the car.
https://www.rockauto.com/en/moreinfo.ph ... 79&jsn=379

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NolimitZ32
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Car: 91 AG2 2+0 TTMT swap/E39 BMW 540i6/E53 4.6is Dinan S3
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MUST READ THIS: https://conceptzperformance.com/wiki/in ... l_Injector
ALSO THIS (if you have time and want to know more): https://www.witchhunter.com/
The flow ratings page on witchhunter is a great resource for figuring out what injectors you have or what flow rating random injectors are.

Want to avoid headaches, ONLY buy OEM NISSAN or NISMO injectors

Since you have the original injectors out, confirm they are in fact original, you can do that with the stamping on the top, I don't remember what the factory number is so you'll have to do some research. If they are OEM send them to get cleaned and flow tested. s*** old OEM injectors are better than any of the garbage aftermarket or remanufactured units, bar none. Too many people have had too many issues with aftermarket injectors on these cars even in stock flow rates/sizes. If they are early redrills (phase 1.5) like described on the wiki (link above) then replace with OEM.

Here is where it gets really interesting, JECS is the OEM manufacturer for Nissan (inc. Nismo), as well as Power Enterprises, Tomei, and a few other high end performance brands. However JECS NEVER sold their oversize injectors to the open market for a LONG time so in the past any time you saw JECS on an injector larger than 370CC it was either a re-drill or a flat out lie. Recently it seems that the have started either selling to vendors their complete injectors or have made the endcaps available which is why you'll see them carried by Z1 and others in a plethora of sizes. Some have had good luck with aftermarket re-drill units but they are hit or miss and most tuners wont touch them. I haven't had the need to screw with injectors for a few years so I have no data on the new JECS units, word of warning, if you decide to go JECS make sure you buy from a reputable dealer, too many fakes and knockoffs out there along with old redrills mixed in with the new units.

In your situation the BEST thing to do is to buy a set of new OEMs from either CZP or SZ, then there is no gamble, you are guaranteed to have premium new parts built to OEM specs. This option is however the most expensive, about twice what you paid for the ones on Amazon. The other option is to get yourself a set of OEM refurbs from a respectable vendor or injector specialty shop, they will likely cost about what the Amazon wonders did but again you will get a flow test result and cert for each injector which will guarantee that you're getting the correct performance. In any case My suggestion is you send the ones you got on amazon back, get your refund and never purchase anything other than toilet paper and swiffer wet jet refills from amazon again.

In general stay the hell away from Amazon for any car parts, there have been thousands of reports of unscrupulous buyers purchasing real (expensive) name brand parts and returning garbage knock offs which then unbeknownst to the seller get put back into circulation. No one checks this stuff. Amazon is the new Ebay for Chinese knockoff garbage except Amazon cares even less, where as Ebay will 1 time out of 10 actually ban sellers for selling fakes, Amazon doesn't care.

scottgas
Posts: 176
Joined: Sat Aug 10, 2019 11:20 am
Car: 1996 Nissan 300ZX N/A steel roof

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I've actually used Witchhunter for my MR2 years ago.

Your chart says the 1.5 injectors have later style body but early connector. Mine look like the purple ones in the chart but are red and have the late style connector. This car only had 47000 miles in 2018 when we got it. It was owned by a retired lawyer b4 us and his local dealer did all the work. It's also a '96 model sonic shouldnt have any in-between stuff.

Also getting them redone is a nogo as we damaged the 1st one trying to get it out. We broke part of the plastic near the top. We stopped after the 1st one when we realized we had the wrong injectors

scottgas
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Car: 1996 Nissan 300ZX N/A steel roof

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Got the car back together last night. Not TOO bad with the egr, coolant hose delete done. Tried to start but wouldn't. 1st hit of the key it sounded like it wanted to start but didn't. Probably residual fuel in the system. Will be diagnosing this evening. Seems like not getting fuel. Just replaced injectors with Amazon one. Yeah I know, didn't find out how picky these are til after I ordered the injectors. Will be pulling fuel hoses to see if I'm even getting fuel to the front. Car ran, not well, before pulling intake manifold to change injectors.

scottgas
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Car: 1996 Nissan 300ZX N/A steel roof

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Getting fuel into and out of the rail. Pulled 1 coil/plug on each side and appears not getting spark. What did I do wrong?

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NolimitZ32
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Are your CPS and PTU all wired correctly? Those are the two things I would check first.

scottgas
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I'll double check

scottgas
Posts: 176
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How could they be wired incorrectly? They were.never unplugged. Am I missing something?

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NolimitZ32
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If they were never unplugged then they probably aren't the culprit. I'm just throwing stuff at the wall now to see what sticks.

scottgas
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gotcha, just tried to start but no luck. I pulled the front driver plug and no gas smell on it. So even though gas is going through the fuel rail I don't believe the injectors are working

scottgas
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I'm at a point now of just throwing wrenches

scottgas
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pulled plugs 1,2, and 3 and maybe a slight hint of fuel but hard to tell. definitely not wet.

scottgas
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Car: 1996 Nissan 300ZX N/A steel roof

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update, checked voltage at #2&#3 injectors. while cranking I'm getting 10 volts on each at the black with red stripe wire but nothing on the white wire. There should be 12 volts on each while cranking, correct?
Last edited by scottgas on Tue Aug 24, 2021 12:16 pm, edited 1 time in total.

scottgas
Posts: 176
Joined: Sat Aug 10, 2019 11:20 am
Car: 1996 Nissan 300ZX N/A steel roof

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Just check resistance, getting right at 12ohm on each injector which is good.

scottgas
Posts: 176
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1 thing, when I got everything back together the battery wasn't strong enough to really crank the engine. Hooked up a jump pack thinking the engine would fire. Had to replace battery as it had a dead sell, only 10 volts. Could the low voltage have cause a problem somewhere.

itsa300zx
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2008 Highlander SR5
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I would:
1) double check all the connections are seated, PTU, CAS, TPS and the three near the fuse box etc. And all 3 grounds.
2) fuel hose connected correctly? They can be easily reversed.
3) physically check for spark to rule that out by the old spark plug grounded method.
4) spin the CAS shaft by hand (with ign in ON position) should hear each inj click.

scottgas
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Car: 1996 Nissan 300ZX N/A steel roof

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I'll check plugs again.
I am getting spark at the plug. Just had wife try to fire the engine while I checked injector connector. Same thing as earlier. 12 volts on the black wire and zero on the white wires

scottgas
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just to be sure, the fuel supply hose goes to the top pipe on theanifold with the hose and what asking us either a pressure regulatory or damper

itsa300zx
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Fuel hose route, I'm not sure if this is your issue though.

Fuel filter, top hard line, fuel dampener(pass side), fuel rail loop, fuel pressure regulator (dr side), bottom return hard line.

Can you hear the injectors click while spinning the CAS?

If you do not see any fuel in the cylinder after cranking a few times, means the injectors are not opening.

scottgas
Posts: 176
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Car: 1996 Nissan 300ZX N/A steel roof

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fuel routing is good.
haven't checked the CAS yet. dealing with bad sinus headache today so may not work on car
with the CAS test, does key have to be on or is that energized all the time?
Since I just pulled intake manifold and changed injectors, what could have been disturbed and what possibly could have been hooked up wrong. the harness pretty much falls where it needs to hook up and there doesn't seem like there are multiple of the same kind of conne toys in the same place that could be crossed.
I doubt there is fuel in the cylinders as the plugs are dry. Will double check though.
What could I have done to kill power to the injectors since car ran, not well, before pulling the manifold.

itsa300zx
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Seems like you do have power to the injectors. With a 96 the key needs to be in the on position. Remember the injectors are just a coiled solenoid and operates in pulses, the clicks I'm asking about while turning the CAS is to hear them active open/close. Also have you scanned for codes?

scottgas
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Car: 1996 Nissan 300ZX N/A steel roof

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Haven't messed with car today. As I mentioned above, fighting bad sinus headache. I AM getting 12 volts to the black wires at the injectors but nothing on the white wire. Is there supposed to be voltage at both wires. I was under the understanding that there is. I put the ECU in diagnostic mode and only get Code 55, No Codes. Since the car was running before pulling the intake manifold could I have somehow messed something up electrically or could I have crossed connectors somewhere?

itsa300zx
Posts: 1243
Joined: Sun May 31, 2009 9:39 am
Car: 1990 300zx NA W/TT swap
2011 Nissan Rouge S
2008 Highlander SR5
Location: up North

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Should be only voltage in one wire not both. Is this injector voltage measure with the ign in the ON position? Constant 12V? Pretty sure you should only get pulse voltage to the injectors during cranking but a multi meter may not pick up a pulse and just show constant 12V.

What injectors did yo install? Amazon?

scottgas
Posts: 176
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Car: 1996 Nissan 300ZX N/A steel roof

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I get 12 volts with key on and starting. Im using a cheap multimeter so not going to show pulse.

Could I have crossed 2 connectors somewhere when putting everything back together? It doesn't look like there are duplicate connectors close to each other that can be screwed up.

itsa300zx
Posts: 1243
Joined: Sun May 31, 2009 9:39 am
Car: 1990 300zx NA W/TT swap
2011 Nissan Rouge S
2008 Highlander SR5
Location: up North

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Did you label the 6 coil connectors and inj connectors? it is possible to mix a few of those up, but should still fire up even if two are not correct.
Coming back to fuel, if dry inside cylinders, injectors are the issue given you have proper pressure.

scottgas
Posts: 176
Joined: Sat Aug 10, 2019 11:20 am
Car: 1996 Nissan 300ZX N/A steel roof

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just turned the CAS and I don't hear anything the injectors nor feel anything through a screw driver. As far as I can tell all coils and injectors are connected properly as we labeled them b4 disassembly. Fuel flow well out of the return line. Engine turns over but doesn't even sound like it's trying to fire

scottgas
Posts: 176
Joined: Sat Aug 10, 2019 11:20 am
Car: 1996 Nissan 300ZX N/A steel roof

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Couple developments. When I turned the CAS I didn't mark the right spot so I vae to try to get it back in the right spot.

Also, I plugged the passenger side EGR solenoid back in and it seems like it's trying to start but doesn't. Do the EGR solenoids ha e to be plugged in?

scottgas
Posts: 176
Joined: Sat Aug 10, 2019 11:20 am
Car: 1996 Nissan 300ZX N/A steel roof

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Think I messed up. When I turned the VAS to check injector pulse all I did was loosen bolts and rotated back and forth. Was I supposed to actually pull it off and rotate it by hand?


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