No idle change when I unplug injector

[unicoder]

Fresh KA-T, ran great the past 2 days.

Started dying at lights on my way home, did simple troubleshooting and searching this forum, ruled out most other issues.

So I started pulling off clips on my injectors to see if the idle would change. The #4 injector makes no difference when I unplug it. These are sr20 370cc injectors I got on this forum, and worked fine since the build on wednesday

Does that immediately mean it's the injector? I can take a test light to the clip to ensure that it is pulsing correctly. Just got to run to the store in the morning and get one.

I did replace the fuel pump (255lph) and the fuel filter (z32 filter) yesterday as well.

edit** issue started on first start after installing my new NGK plugs. I checked to ensure the wire was on the plug and it is. Going to try a cap and rotor, and swap injector 4 with a different cylinder to see if the issue switches cylinders

[anti tyler]

But the real question is, did you remove the plug wire to see if the idle changed?

[unicoder]

Lol, yeah I started troubleshooting this morning. I am limited on tools here so had to run get a test light and just got home.

I was able to swap the injector #4 with injector #1, and the issue remained in cylinder #4.

Since i have never changed the cap and rotor on this car, I went ahead and ordered some because I should have long ago.

I swapped cylinder 3 and 4 plug wires at the valvecover and the distributor and there was no change.

I am about to run outside to test the plug wire for spark now that I have some tools here. Will report in!
- I kinda hope there is no spark, as that will make the resolution a lot easier than chasing the harness to the ecu LOL

[unicoder]

update: confirmed i am getting spark, and the injector clips are getting 12v.

And to answer anti_tyler: When i remove the #4 wire it idles up, but if i remove any of the other 3 it gets rough for a second. Not sure if that means anything

[Hoffman5982]

If you have spark and fuel and that cylinder isn't firing, you need to check compression.

[brndck]

1. Compression test all cylinders
2. Leakdown test all cylinders

[anti tyler]

When you say fresh KA-t, I hope that doesn't mean someone installed the #4* cylinder rings incorrectly.

[unicoder]

ok, we aren’t quite there yet. The car ran perfect for first 3 days with the turbo kit. I have not hot rodded the car. I finally got my plugs I ordered and the issue started on first start after plug change.

Next step IMO is swap back in the old plug because this new plug may be bad and sparking to the head in the spark plug tube, as well as noid light my injector harness

If both of those fail I will compression test again, compression was 155 on all 4 cylinders yesterday

[unicoder]

Alright, noid light was good, injectors are pulsing correctly

I pulled the new plugs and put the old ones in, and now it idles enough that you can tell the difference on cylinder #4 when i unplug it and replug it.

However, its still missing, and running EXTREMELY rich, blowing out smoke.
- Cylinder 1 even had tons of vapor coming out when replacing it.

I still think its the injectors, they are used from a user on here, and the o'rings were looking a little torn on the 2 i swapped today. But next my plan was to do a compression test, and going off of that, re-oring my injectors and hope they are working then.

I just find it so strange that it ran fine, and then change so much all of a sudden.

here are videos of the smoking and the vapor from the cylinder:
vapor
rich smoke

[brndck]

Originally Posted by unicoder

Alright, noid light was good, injectors are pulsing correctly

I pulled the new plugs and put the old ones in, and now it idles enough that you can tell the difference on cylinder #4 when i unplug it and replug it.

However, its still missing, and running EXTREMELY rich, blowing out smoke.
- Cylinder 1 even had tons of vapor coming out when replacing it.

I still think its the injectors, they are used from a user on here, and the o'rings were looking a little torn on the 2 i swapped today. But next my plan was to do a compression test, and going off of that, re-oring my injectors and hope they are working then.

but if you move that injector to a different cylinder, the misfire still stays on Cyl4?

[unicoder]

When I moved the injectors yes, there seemed to be no difference when plugging/unplugging the injector clip.

which leads me to believe it was a no spark issue or ecu issue, but since the noid light worked and the line had spark, it led me to the plug, and when i put the old plugs back in, it improved and you could now hear the idle change up and down when removing the injector clip.

so now i am to either compression issue, or dumping fuel due to bad oring/injector still
- i will run a compression test tonight/tomorrow and if there is still compression i cant see it being anything else but the injectors.

hence why i wanted to tap on all of your shoulders.

[unicoder]

update, cant compression test until tomorrow. So i pulled the plugs and held a light up to each cylinder.

Sure enough #1 was full of fluid to my surprise. Got some of it out onto a long q-tip and it smelled like gas, lit it with a match and might as well have been a road flare.

Must have missed something in my initial diagnosis, I feel that injector #4 (which is now injector #1) does have issues and is flooding my system. I am likely replacing this injector pending the compression test tomorrow.

[unicoder]

I feel like such an idiot, first I should have put new o-rings on these injectors when I got them used. Then I missed this when I swapped it from #4 to #1 yesterday. You can see where the previous owner tried prying off a pintle cap, and bent the bottom filter ring, likely setting the o-ring up for this when I put it in. Not his fault though! I am sure the injector still works, just needed maintenance on my end.

I think we have found the culprit. Whole new o-ring and filter kit on it's way. Thanks everyone

[da_crew10]

Originally Posted by unicoder

I still think its the injectors, they are used from a user on here, and the o'rings were looking a little torn on the 2 i swapped today.

Tisk tisk, you knew they were effed and still ran them? Come on friend!

[unicoder]

Originally Posted by da_crew10

Tisk tisk, you knew they were effed and still ran them? Come on friend!

I knew way better. My car was down 90 days for this kit due to an 11 week back order on one of the parts. As much as i tried to stay patient, i threw these in without refreshing them.

If you are reading this 10 years from now and have the same symptoms, shame on you too!

[brndck]

glad you found it. I've had the same issue, torn oring causing a cylinder to flood out. easy fix tho!

i'll take a cheap fix over an expensive one anyday!!!

[anti tyler]

Well don't jump the gun now... Until you replace an o-ring and the problem goes away, don't say you found the culprit.

I've had 2 KAde's with smashed up o-rings and plastic housings south of the basket. It never caused an issue like your explanation. Just be weary...

[unicoder]

Originally Posted by anti tyler

Well don't jump the gun now... Until you replace an o-ring and the problem goes away, don't say you found the culprit.

I've had 2 KAde's with smashed up o-rings and plastic housings south of the basket. It never caused an issue like your explanation. Just be weary...

Well, here's an update.

- Refreshed old injectors with new o-rings, pintle caps, and filter covers. Smoke situation went down by 80%, just smoking rich from the r.s. enthalpy tune at idle I think.

- Still missing and idling rough, went dead when I tried to move the car. So I ran a compression test. Still good at ~155 per cylinder

- Put the old plugs back in. Car went back to normal, drove it around the yard twice, never went dead, idle smoothed out....

As i said before (but didnt think it was important) this issue started when i put the new plugs in, so let's visit that for a second.

original plugs were NGK BKR5???, then I switched to BKR7EIX-11 per Ka-t.org recommendation.
- i think these plugs are too cold maybe, since its 2 heat ranges colder. I read that some people reported strange idle and fouling.
- Since im not hot rodding the car, im leaving the BKR5??? plugs in and going to give it a test drive in the morning.

Then im going to reach out to martin about this super rich idle if everything goes back to working ok again

[unicoder]

Changed the cap and rotor, this morning it was hardly smoking at all. Just enough vapor to show for the tune, but then when i tried to drive it around the house it fought like an unbroken horse

- pulled hot pipe, no oil in it.
- new dist cap and rotor (helped a lot for sure)
- code 34: knock sensor (had this since april, it at least drove!)
- ordered new MAF just to rule it out (i had cheap amazon maf) will know more shortly
- switching to BKR6EIX-11 plugs today
- tps tested good

edit**
- got an OEM Nissan Reman MAF with 1 year warranty, pigtail fits this way better than my amazon maf, now car cranks and dies instantly. Starting to look back to fuel related

edit**
- brand new (reman) sr20det injectors, with OEM Nissan Reman Maf.
start it and it goes dead, unplug maf, and it will idle fine in limp mode. Before I assume bad MAF, going to get a multimeter and make sure the voltages are getting to the ecu

[unicoder]

Checked the voltages on the new reman MAF from Autozone. Signal wire was not putting out enough signal with the key on.

Turns out autozone didnt even give me a reman MAF, they gave me someone else's core that ended up on the shelf. I got them to swap it out for a brand new one.

Car fired right up, drove it around a bit and seems to be fine.

Thanks everyone!

[Green Arrow]

Damnnnnnn
Oriellys man, autozone is terrible
Glad you got it worked out..