RB25 Code 21 hesitation

[RBSilvia]

Hi guys. I'm trying to take my S13 on a road trip within the next week, and need to get it running right.

I just put on a new intake manifold, and shortened all the wires in the engine harness (wire tuck). Before the wiring job it was running great

After getting all the piping back on, the car started right up and ran great for a while. Then after parking for a bit, it was hard to start (had to give it a little gas and it took a bit of cranking). Still ran fine for quite a few miles.

Next time I hop in the car it starts really hard and runs like crap. Im pretty sure cylinder 1 isn't firing. Tried switching injectors, same thing. Switched plugs and coils, same thing.

I'm getting code 21 and 34 right now. I think it's possible that the knock sensor code could be from how rough it's running so i want to get 21 figured out first.

I inspected my wiring job on the ignition harness and it looks fine. All coilpacks check out with the multimeter. What else should I check?

[RBSilvia]

Correction. It's cyl #5 that's not firing. Not the coil, not the plug. The plug was wet, so I'm assuming it's getting fuel.

Subharness has continuity, and my solder joint looks good where I shortened the wires. Could be the ignitor maybe? Where is it on the RB? Is it the brown box?

btw I cleaned my MAF... no change

[RBSilvia]

Ok. So I just found out that my Series 2 RB25 has ignitors built into the coil...correct?

So since it's not the coil or plug, it pretty much HAS to be wiring....right?

[RBSilvia]

So I tested each coil/plug by turning the CAS by hand and looking for a spark. Repeated the same thing with the injectors

So I actually am getting spark to #5, and fuel also. Why isn't it igniting? Compression is good. Doesn't make any sense...

[d356bud]

might be a weak spark

[RBSilvia]

just made a breakthrough. swapped the injectors on #4 and #5. And the symptoms switched to cyl. 4. Popped out injector #4 to notice the smaller o-ring was chewed up. So I'm assuming that fuel was leaking around the injector and flooding out the cylinder.

Could the code 21 be from me unplugging coilpacks?? Or do I still have another problem to solve?

[d356bud]

just rest the ecu and fix the o-ring problem and see if it comes up again

[RBSilvia]

Any idea what injector o-ring I can use?

300ZX or somethin?

EDIT: looks like 95-96 300zx rings will work

[RBSilvia]

So i ordered a Z32 injector seal kit....and it's not right

The lower o-ring on my injector is much smaller than the z. There's a seal kit for the RB on ebay, but I need something NOW.

It's weird because I've found a few sources online that state the Z32 uses the same injectors, but this doesn't seem to be the case. Also, i've read that 95-96 is different than the older style injector, but part numbers for the seal kit is the same for all years. Any ideas?

[RBSilvia]

It looks like a VQ30 injector from a '98 maxima is almost identical. I'm gonna try using that seal kit and let everyone know how it goes

[d356bud]

I just bought a o-ring kit like this one:

http://www.harborfreight.com/180-piece- ... 67525.html

[l0nestar]

Physically the RB25 injectors are the same as KA (just CC flow is higher on RB25).

You can either go Nissan OE, or like D356bud did and get an o-ring assortment.

[RBSilvia]

I bought 6 seal kits from O'Reilly's and it still isn't sealing properly. I've tried seating them twice, pushing them in as hard as i can. Then I tried using white lithium grease and finally motor oil. Still having problems with fuel leaking around the injector

I can't believe you guys are getting hardware store o-rings to seal. Tomorrow I'm going to try getting some OEM Nissan o-rings.