dveneman

I am wondering the same. Do just the entrances typically get blocked?

Yamae

.
The answer is No.
The 2 entrances are not easily blocked because the diameter is much bigger than those small ports (air mix passages) at each injectors. Those small ports are blocked prior to entrances. It often needs a full can or more of carbon cleaner with the compressed air to clean. But sometimes you need to clean ports removing injectors and using ultrasonic cleaning machine when those were badly clogged and completely blocked. The link below is all in Japanese but it explains the case to clean removing injectors.
https://blogs.yahoo.co.jp/ks1106spiderman/1099329.html

bradland

Thanks again Yamae, I have a question for you.
I've cleaned these passages on my 99, which I no longer own, but a couple days ago tried it on my 06 and had different results. Obviously the throttle body is different and when I removed the cover to access the holes the car would not start. My 99 always stayed running with the cover removed...? Any thoughts ?

Yamae

The 06 has a newly designed engine. The engine management is also new. The mechanical structure is also different for an example the starter motor is not located in the valley of 2 banks. It can be accessed easily. So things are quite different and the same techniques can't be applied in most of the cases, I think.

Sorry about the starter motor. A 07 has it at the side of the engine but 06 has it in the valley. Anyway, a 06 uses newer managements.

spuds

Thanks,that 07 starter motor info very good to know.Is that when the timing chain started too?Also did the v8 ever advance back to a non interference engine?

213374U

Correct, 07+ uses a timing chain.

Scraape

misfire on cylinder 2 is still there . Does not throw a code for it all the time , but I can feel the "miss" most of the time regardless.

I am running chevron techron fuel injector cleaner or whatever it is right now, in case my cylinder 2 injector is clogged.

I want to unplug my coil connector and fuel injector connector with the car runnning to test them out, but the intake covers it pretty good

Scraape

did some more tests today to see if i could hunt down why my car is misfiring on cylinder 2. left cylinder 2 injector unplugged and started the car....it was missing like usual, plugged the injector back in and it honestly seemed like it started misfiring even worse! My friend thinks the injector is stuck open.

I took the new duralast coil pack off cylinder 2 and put the old one back on, since i don't believe that is my issue.

When i put the old one back on, the car still noticeably misses, but it doesn't throw a code .

This is making me think it may definitely be the injector on that cylinder. I went ahead and bought a new set (8) of remanufactured injectors. Hopefully that will do the trick!

Scraape

anyone have a tutorial or factory manual pdf file on how to replace the injectors ? I'm guessing you can just remove the fuel rail without removing the intake manifold...

bradland

Hope this helps...

400fanboy

For what it's worth, my car exhibited this as well, it turns it it was the cooling fan. If you rev the car while in park just a little bit (blip to 2k rpm) you can feel it.

You should hear the fan roar when the car first starts up. Then it quickly goes silent.

The clutch pack had died in the open posistion and the fan was not spinning. Thankfully it was in the winter where this wasn't a problem. Replaced it and the vibration at cold\idle went away.

While it seems you found the misfire, just putting this out there.

Scraape

I actually replaced my fan clutch recently , but i appreciate the help!

Scraape

problem still exists. Ive replaced all 8 injectors, problem has not gone away. Pretty frustrating.

Yamae

Sorry to hear that. I'd check waveforms of the injector and the igniter using an oscilloscope. Other than those, I'd check the compression using a compression meter.

If an oscilloscope is not available easily, the alternative method will be to use an LED with a series resistor 330 to 1K ohm in parallel with the parts driven. In this way the drive signals can be confirmed by eyes. Compare the brightness with other cylinders, you can judge that the driving signal is OK or not. This is the way I of do at shops when I don't carry my oscilloscope. This technique is now widely used at my local shops and dealers. Electrons can't be seen by human eyes but there are methods to see those simply.

Scraape

Thank you for the suggestions Yamae. I will try that and I will also check compression. I'm still thinking it is not a compression issue personally.

My car runs like ****!! Still trying to hunt down this issue. Doesn't blow any smoke from the exhaust or anything.

Spark Plugs have been replaced, all 8 injectors replaced, coil packs swapped out with a new one.

At one point I was getting misfires on Cylinder 2, 5, 7. Cylinder 2 is the one that consistently misfires. I pulled the plugs on those cylinders and they were certianly not fouled, let alone from a rich condition(no black on the electrode). Am I safe to assume this is a lean misfire ?

Car seems to misfire at low RPMS(blinking CEL) but accelerate decently above 2k RPMS.

I still need to swap the Coil Pack connectors on those cylinders