Injector Confusion

[SauZey1]

This will be a bit messy, but its what im dealing with. So its a 90 na M/T. Basically my car will run on 5 cylinders very briefly. And its only at idle. The idle goes from normal to 5 cylinders. Think im running a bit rich to. Awhile back i ohmed the injectors. But driver side was all good. There was one on the passenger side that came out bad, cylinder 1. Then i put the alligator clips on the ohm meter and it read like 12.2 and so did cyl 3. I can also hear them ticking with a screw driver. Fast forward to recent I have caught the cyl that doesnt fire, cyl 4. Its only briely tho and sometimes if i catch and push down on the injector plug it goes back to normal. Ive even down a power balance test with the injectors and even coilpacks they all fire MOST of the time. Again its just briefly it runs on 5. Its like loose connection or something or maybe something just fails in the moment. Im just going to say its the injector. Its still old style. Any input? Keep in mind im not a mechanic thanks.

[itsa300zx]

Most likely corrosion in the connectors, very common for these 25+ year old cars. Try cleaning the contacts, if the connectors don’t crumble when you disconnect them. Biggest challenge will be removing the metal “U”clips that hold the connectors in place without damage to the plastic. I refer those clips as “b****” clips.
I’d suggest sourcing 6 new connectors with pig tails and replace old ones. Look locally for help if possible, the internet can only help so much.
You don’t need to be a mechanic to fix BUT do need a bit of patience, skill to work on these cars.
Also look at the connectors for the PTU and clean as needed.

Hope that helps.

[SauZey1]

Most likely corrosion in the connectors, very common for these 25+ year old cars. Try cleaning the contacts, if the connectors don’t crumble when you disconnect them. Biggest challenge will be removing the metal “U”clips that hold the connectors in place without damage to the plastic. I refer those clips as “b****” clips.
I’d suggest sourcing 6 new connectors with pig tails and replace old ones. Look locally for help if possible, the internet can only help so much.
You don’t need to be a mechanic to fix BUT do need a bit of patience, skill to work on these cars.
Also look at the connectors for the PTU and clean as needed.

Hope that helps.

Thanks for the reply yeah ill give it another look but the first time i did they looked clean. Yeah i think the PTU is the the original one and it does have corrosion. Honestly there has already been some new pig tails spliced in. The wiring harness has been hacked a little. The car is stock but has been neglected from my understanding. Any suggestion on cleaning corrosion?

[itsa300zx]

I use electronic contact cleaner, thin blade file and very small wire brush to scrub all the corrosion off. Add some de-electric grease after cleaning to give any extra layer of protection.

[SauZey1]

I use electronic contact cleaner, thin blade file and very small wire brush to scrub all the corrosion off. Add some de-electric grease after cleaning to give any extra layer of protection.

Add the grease to the pin on the ptu?

[itsa300zx]

Yes, I do it to all connectors

[SauZey1]

I did the clean ptu a little bit but it didnt do much. Its a given because I couldnt fully open up the connector part of what i believe is the sub harness to the ptu. There is corrosion on top. But I forgot you could pull codes. Im sure something will show up and give a little guidance. My car is a 90.

[NolimitZ32]

Some of the early 90 models had issues with timing due to heads being machined incorrectly. However unlikely it may be your issue.

[SauZey1]

Some of the early 90 models had issues with timing due to heads being machined incorrectly. However unlikely it may be your issue.

I tried to run codes today. Got no malfunctions just code 55. Witch leads me to think its something mechanical? Like something internal like a burnt valve? I might have a compression done to it.