fire120ball

So when i reset the code it runs great until the pcm relearns itself, I have so far changed my plugs out from my brand new NGK to my stockers, I also changed my MSD wires to the stockers, I have checked the spark and it looks good, I just now checked the voltage on the Fuel Injector and it was at 14.3. I also just listened to the injector with a screwdriver compared to the other injectors and it sounded like it was working. I had done a leak-down test when the motor was out, and it came out perfect, I also had the intake off for about 8 months and it went through basically nights in a barn. not direct weather, but condensation dust, etc.... Could the injector have gotten clogged? and How exactly do you change the Fuel injector too another cylinder to check if it is a injector? Guy's im at a loss, I searched everywhere for this.

Today I also had it ran by a friend at a auto shop with a scanner that scans all cylinders, and #1,5,6 were missing, but out of 20. 1=2 misses 5=1, and 6=14-17,18
I almost thinking it could be a crankshaft positioning sensor. Am I on the right track guys??

fire120ball

No one?

LS1WS6dreamer

iTrader: (1)

So if you unplug the battery and everything resets you can drive the car fine or a while?

When my 02 sensor started going bad I would get the SES blinking at me. Multiple misfires or some **** when I ran the code. Did it off and on and would literally make the car surge and jerk, but it only did this after driving it a while.
Replaced 02 sensor and everything was fine.

I wouldn't think that a injector would be clogged and then when you unplug the battery and plug it back in it runs fine for a while. I would guess a clogged injector would stay clogged. Not intermittent
However, the injector could be going bad. Not necessarily clogged.

Coil pack harness backwards???

Sorry I couldn't help much. I am just trying to throw and idea or two out there. Stimulate your thinking; sometimes it helps people figure stuff out.

GMRL

I went through the same thing a while back in my 02. I pulled the rail off, and cleaned it and the injectors individualy in a parts washer. Hasn't done it since, its been about 20k miles.
Weird thing is that it would do it intermittently. Since the regulator is in the module in the tank, debris goes all the way to the injectors and stays there.

fire120ball

I'm thinking they might be clogged so when I first start my car it starts to run rich so its putting more gasoline into the cylinder so once it leans out it is not getting enough fuel? I will take my injectors out and clean them, thanks guys

Darkman

iTrader: (2)

See attached.

fire120ball

Update,
I pulled the injectors all out and hit them with some carb cleaner and they all looked like they were in good shape, descreened my MAF at the same time. Put her all back together and the code is still on but its not surging like before.

Next thing im going to do is switch the coil packs, see if this helps. and do a compression check at the same time... if this fails I will be thinking its the crankshaft positioning sensor or the 02's.

I will swap the 02's to different sides to see if I get any affect... And if this fails... I need you guys! I know my valve springs are not broken, my lifter? brand new pushrods. I just want her to run good again guys!

jimmyblue

iTrader: (11)

I think this is an injector imbalance. If you have four of them
and one shoots lean, the fuel trims will pull the bank rich to
make up for that (running crappy, and the lean one will still
perhaps misfire).

On the other hand if one's a drooler, the bank will pull leaner
and the other three ought to be showing elevated misfires.

The reset making it run better temporarily means something
like this is going on. You might swap injector 6 for 4 and see
if the problem moves. If it doesn't then you have to look at
single runner vacuum leak or a spark path problem. Misfires
of any sort can fool the O2s into mistrimming, including a
spark (not intake AFR) problem.

fire120ball

Jimmy, I did switch the two but I still have a mis on 6... I changed up the coil packs today with no luck... Still p0306..... I'm at a loss, I plan on doing a compression test (even though I did a leak down when my motor was out and all came up perfect...) If the compression tests tell me nothing I will proceed to swap the 02's for sides... I need help...

JaYZeig

iTrader: (11)

so, if youve tried all the simple stuff, and its still pinpointed on cyl. 6...its gotta be a mechanical issue, broken/cracked valvespring, loose rocker, bent pushrod, or even slightly collapsed lifter. youll still get compression on that cyl and have minimal leakdown..somthing id start looking into.its not hard to pull the valvecover and take a look.

fire120ball

Its not a loose rocker, nor bent pushrod (Brand new pushrods installed myself), possiblity of a lifter, and it is not a broken valve spring. I'm almost thinking a crankshaft positioning sensor?! Does anyone have any experience replacing one of these? And if so where is it located? Thanks guys....

lemons12

iTrader: (71)

Skimmed thread, have you ruled out o2s? Very common.

FWIW, I have 2 if needed.

Is it loaded up/back firing at all? Does the idle act strange at all?