Crazy Injector Wire Reading

[sdhsbaseball]

So I recently installed the new style injectors in a buddy’s car and after we got everything installed we fired the car up and it was only running on five cylinders. After doing a power balance test we realized it was the 5th cylinder or the passenger side cylinder closest to the firewall. So I ended up doing a lot of things to figure out what the issue was.

Ohmed the injector ~ in spec
Swapped coil packs ~ so I know the coil pack works
Installed new coil pack connectors so I know the connector isn’t loose
And yes the wires are installed correctly since they follow the same pattern as the other coil packs.
Then I decided to see if the injector connector was seeing a positive amount of volts upon realizing that one side says a +12v and the other were seeing at .002volts... So I though mmmh maybe the solder joint came loose. So after checking everything again I stripped both wires to get a clean test with no solder or anything and the same numbers held true.

No I tested all the other injectors and one lead is reading a +12v while the other is reading a +.3-.5ish volts and it was like that for all injectors. So right now I am beyond stumped....

[nissanfreak12]

Have you checked the continuity between then injector connector and the connection at the ecu? Could be possible it has corrsion somewhere between these points, or even a pinched wire thats on a few strands.

[sdhsbaseball]

thats my next step, but i have a feeling there is an issue with the ptu since i was reading that when you pull the spark plug and its wet that means the injector is working but no spark, and i know its not the coil pack since i have switched them and the the apark plug looked good.

[nissanfreak12]

I was gonna make a comment about the PTU, But I think that is suppose to amplify the signal to the coils. I didn't think it had anything to do with the injectors. I know the CAS tells the comp when to fire the injectors, but thats just one wire going to the comp.

[nissanfreak12]

Have you pulled the spark plug?

[sdhsbaseball]

yes spark plug was pulled and it was damp/wet which means fuel is getting into the cylinder, I realized this after reading some other threads i found LOL I thought to my self it cant be the injector if there is fuel in the cylinder but after working on the car for awhile in the heat you dont always make those connections while thinking of it haha

[Chattzx]

We still have no firing to the 5th cylinder.... fuuuu

[wrz32]

A valve

[nissanfreak12]

Have you tried pulling out the coil pack with the spark plug connected , set the plug on some metal and see if there is spark? Here is a thought, what if the injector is just stuck open enough to foul the plug. If its possible, maybe try swapping injectors and see if it has the same issue in the new cylinder. This may seem like a long way to do it, but it will give you an answer.

[sdhsbaseball]

the ecu was dead on that cylinder a local z shop found that out... but since the ecu got switched his car has been running perfect since thanks for all the help

[nissanfreak12]

Glad to hear you got it fixed!!!