More About Fuel Injectors

[GerryO]

Ran across these sources of injector related information today:

http://www.maeganandjoe.info/temp/Z32/C ... ailure.pdf

http://twinturbo.net/nissan/300zx/forum ... 1-2-3.html

And does anyone know whether our fuel injectors are switched or not? I suppose it won't be to difficult to determine.

[swimshark]

they changed the style of injectors on the Zs in 93. all the J30s come with the new style injectors so I do not believe this is an issue. out harness is also different than from the 300zx. ours has those same connectors but our whole injector/coilpack/ptu harness completely disconnects. on the 300zx it will not.

[GerryO]

Our J30t was made in May-92 and I have one failed injector (infinite resistance = coil/connection failure) that I'll dissect, plus I'll be checking for an unswitched 12VDC to the injectors from the harness.

[driverdriver]

Nice info GerryO

[GerryO]

Nice info GerryO

And there's this too.

http://maxima.theowensfamily.com/tsb/NTB94-002.pdf

Which supports the fact that even the new style injectors are obviously somewhat prone to coil failure.

[beklear]

Hi Gerry O. Have a '93 J30t w/141k. Been sitting awhile and a squirrel got under hood and chewed on #2 injector coil plug wires (3 wires) I spliced in new plug and was working fine for months but now check engine light comes on and off. Will this cause injector to fail or has coil pack gone bad? Thanks

[yodawill2000]

Ohm out the Injector.
Should be around 14 if all is well.
Does the engine shake when the CEL comes on ??

[GerryO]

An injector that's failing due to a bad coil can work intermittently for a while, causing the CEL to go ON and OFF. Pulling stored ECM codes can tell you if an injector related problem is the reason for the CEL going ON and OFF.

Suppose a bad harness connection to an injector would be the same to the ECM as a bad/open injector coil.

Based on all that I've read, injectors fail far more often than coil packs and both are easily tested using a multimeter. A 12.5 ohm resistance reading is what I recall for each of the six new injectors that I installed a few years ago.

[beklear]

Hey Guys. Engine doesn't 'shake' when I disco coil connection. Switched coils and spliced in new coil connection but CEL still on but getting no spark and or power to #2 injector. Is this a relay issue vs replacing injector? ThANKS!

[driverdriver]

Ohm test your injector. A reading in the 10-14 ohm range indicates that it is good. Anything above or below means it needs to be replaced.

[GerryO]

Hey Guys. Engine doesn't 'shake' when I disco coil connection. Switched coils and spliced in new coil connection but CEL still on but getting no spark and or power to #2 injector. Is this a relay issue vs replacing injector? ThANKS!

Disco'ing a coil pack or injector on a working cylinder should make the idle slow down and reconnecting should make it speed up again.

If disco'ing one or both on the #2 cylinder had no effect on the idle speed, something was bad to begin with. Ohm checking the injector and testing the harness connection with a Noid lamp would be the next logical steps.

[beklear]

Hi Gerry O and all. Hook up with my man Swimshark in Atlanta and he did great job on replacing injector and other stuff. He's good! Now I know how to next time. So far running great! Would you or anyone else know best resource to find good used black fenders, hood and bumper for my J? Trying to do restoration and may be cheaper for me to replace for now than paint until I get more important stuff done. Thanks again. Hope pics post.

[beklear]

Forgot to ask about new OEM vs OEM remanufactured injectors for Js. Is there a difference? If so, please recommend what brand and type.

Thanks again,

[driverdriver]

It depends on how long you want to keep your J for? Stick to OEM if you want to keep it for awhile, go with aftermarket for a shorter ownership experience.

[yodawill2000]

Although I Agree with Driver as always.
I have two Injectors in that were OEM spec (Broad Term)from Auto Zone, and after 20 to 30 K (Miles) so far all is still well.
As most J's running now have considerable mileage on them not getting 10 years + out of a component is a Moot point.

All I want for Christmas is 300K !!!
A few years away though.

[beklear]

Thanks again guys. Love my triple black J. Only has 141k. Been a long grueling restoration project. Gonna drive till the wheels fall off then push Are there certain brand name or manufacturer of Injectors that are better for J's? Can anyone advise how to upload car pic?

[driverdriver]

Instructions for posting pictures:

how-to-post-pictures-using-photobucket-t521110.html

[GerryO]

Thanks again guys. Love my triple black J. Only has 141k. Been a long grueling restoration project. Gonna drive till the wheels fall off then push Are there certain brand name or manufacturer of Injectors that are better for J's? Can anyone advise how to upload car pic?

This is the correct OEM injector (JECS and NOT Bosch) for our cars. I'm not sure what other engines it might fit and who has new ones for the best price, but you can probably avoid paying sales tax and get free shipping (ground) somewhere.

My issue with reconditioned/refurbished/rebuilt injectors is although they've been gone through mechanically, their coil is still old and coil failure seems to be the most common injector failure mode.



http://www.z1motorsports.com/product_in ... ts_id=3268

[swimshark]

JECS are OEM injectors. i bought 1 new bosch and 5 new JECS and the bosch lasted me 3 months and it promptly died. may not be the same for everyone else but ill stick to the JECS which were still cheaper than the bosch i bought.

[GerryO]

JECS are OEM injectors. i bought 1 new bosch and 5 new JECS and the bosch lasted me 3 months and it promptly died. may not be the same for everyone else but ill stick to the JECS which were still cheaper than the bosch i bought.

Thank you very much for the correction/information!

[swimshark]

i always go with the Z1 parts cause they are cheaper than the parts you get from the dealerships and they know their specifics about the VG30DE motors so have helped me out a lot when doing some work on my J30. when i went to replacing my injectors about 3 years ago, i first went to the dealerships to get quotes. Nissan wanted $198 per injector and i had to still buy the o-ring kit for all 6 which was another $17 i think per injector (mind you you can get o-ring kit from advance auto for $7). Infiniti dealership wanted $158 per injector and also had to buy o-ring kit per injector as well for around same price as Nissan's quote. Z1 sells the JECS oem injectors right now for $108 a piece (they were $109 when i bought them) and they come with the o-rings installed already.

i actually had a little bit of fun with Infiniti and had them give me a quote on doing the injector job. i didnt answer the phone call an hr later after the guy finally called back cause i just wanted to hear the spiel. he started off with price of injectors totaling around $1200, then $90 for some other parts, then $1700 for labor and another $120 for shop fees. i about fell out of my chair laughing when i heard they were going to want around $3100 to replace 6 injectors on a 16yr old car that is worth about $2500.

why i am a strong DIY type of person when it comes to fixing these cars, it will save you money and make it worth it to fix your J and keep it running good.