Miss in #5 cylinder

[dfeller]

I’m having a miss in the #5 cylinder. I swapped out coil packs with a working one and it’s missing. I have new spark plugs and injectors. Any ideas? I’m thinking it’s in the wiring. Thanks

[macgiver]

mac , was miss only reported via trouble code scanned ? Did you do the "rpm drop" test where you unplug suspected injector where it gets no rpm's change as compared to a perfectly running cylinder which tends to drop rpm's by around 200+ ? Possible to do that test by "killing" the cylinder by unplugging coilpack too.Does that plug from #5 (always number your old plugs as they are pulled) look like the others , or how is it different? Specific to your question is WIRING - now ALL low voltage (13.8 to 3V) automotive situations can be "picked-up" and "observed" with a "Logic probe" (NOT HI-V spark /wires/plugs!) . You MAY unplug coil pack or injector ,"probe" connector and see pulses/hear beep tone from the L. probe.Alternately- spark can also be observed by laying "out" coil on top of motor using inserted screwdriver for spark gap.And also single injector can be HEARD using stethoscpoe(mechanic's steth = hose) although SEEING a spark is believing , HEARING the injector = NOT PROOF POSITIVE it DELIVERS FUEL.
So spark , fuel , fixed here? unless new parts bad,,,? Next IF still showing a DEAD #5 ,pull that plug & compression test.If within the ballpark , If not ? You go and pull some other plug for compression on that cylinder to verify/compare the #5 test.
You may not have to compression ALL here - just to discern IF 5 is WAY off.
Sounds backwards , but had to get the diagnostic tips out there first - "REPORTED MISS"? , what does it feel driving ,is it subtle? does it feel like a completely DEAD cylinder ?etc. Good luck

[brian300zx]

Check all your connectors for corrosion. Check your ptu subharness. Usually what causes a misfire is spark plugs, fuel injector, coil pack. Ohm your injectors just in case don’t overlook that just cause they’re new.

[DCaff300ZX]

Check all your connectors for corrosion. Check your ptu subharness. Usually what causes a misfire is spark plugs, fuel injector, coil pack. Ohm your injectors just in case don’t overlook that just cause they’re new.

^^^^This.
Most issues with connectivity and the Z32 result from corrosion of the connectors, especially under the hood. It's a good idea to check ALL wiring and connections any time you do work on your Z32 as there will be corrosion and that may be your sole issue...and if not, surely helps the repair work process removing that issue and ensures your repairs work as best possible and without further hiccups.
Should issues persist, use the FSM and the tests in there to work your way through the vast lack-of-connectivity-induced, misfire/stumble/hesitation swamp that the Z32 is.

[echonightsi]

DO you know what injectors you put in? From Zperformance or the correct ones? My buddy put cheap rock auto injectors in his Z and later had to replace 1, then 2. then 3..... The Z32 is one picky %^$%^. Have you done a compression test?

[Petcha]

Hmm im starting to see a pattern with missing on cylinder 5 before the PTU series 1 goes bad lol

[Ace2cool]

It's amazing to me that people are still running functional series 1 PTU's.

[NolimitZ32]

I want one just to hang on the wall, I've never actually see one in person.