Injector question

Hi guys. I have a question about injectors. Cause i changed everithing possible and i just think probably injectors cloged. I have missfire symptoms and no SES. Tried 3-4 times cleaners. Question is, how i can clean them manualy without major repair. I know i need somekind of tool for that. Where i can get it or you think dealer is cheaper. I was 3 times at the dealer and they cant find my problem. So what you guys think? More info on "NO CAT" same page of this forum.
Thanks.
3.4, 94000, 2003.

Most shops will clean injectors for a fee. Napa sell cans of cleaner and you plug the return line and use an adapter which screws on the can and connects to the fuel system. Some shops have a unit which you pour in cleaner then pressure with air. Unplug your fuel pressure regulator vacuum line if leaking replace. Then pinch off the return line where it has a rubber hose vice grips or a special tool. If it runs a lot better replace the regulator.
Sometimes it makes a big difference.

There is a product called "Seafoam" that is supposed to do a real good cleaning job... http://www.seafoamsales.com/

I've never used it myself so I can't give you any first hand experience...

Thank you for info. But my point here is: i wanna know how hard to clean them by my self, and what i need for that. Aproximatly how much this gonna cost for me. I tried before seafom and this didnt help. Maybe it hepld but i cant thinc anything else causing missfire. I change coils, ICM,Wires,Plugs, bunch of sensors. I cant think anything else. And i tried couple of times those cleaning stuff. I think maybe they really bad cloged, i mean thru the tank and vacuum line is not gonna help, probably i have to clean them manualy. I not sure this is injectors my problem. I just wanna use method illumination, sinse my dealer cant figure out the problem.
Thank you again.

If you don't have an injector cleaner ask a local garage for a price. A lot of places like quick tune up do this. Ask for a price before you start or ask your dealer. Just allow a quick tune place to clean them watch if possible.
Otherwise if you need more work go back and complain to the original shop.
I would think around $80.00 a hours labor and $20.00 for a can of cleaner.
In the country a dealer is about $30.00 hr flat rate cheaper.
I have cleaned some and the vehicle ran like a new car sometimes no difference.

Ok thanks. And one more question. Is it possible my coils is bad. Because look what i have. ACdelco wires and plugs(0.06), wells- ignition control module, and coils from e-bay 10$each. I dont know what brand are they, but resistance is 12-13ohm. You saying about cleaners, i tried 3-4 times different kind even thru brake s vakuum line. and that didnt help. I chekcd alredy everything pulley, belt everything and still cant figure out why its idleing not smooth. I think my loss of power and hard shifting because of that.
Another thing is it possible EGR can be mulfunction and not trowing a code, or its all the time should triger SES. When i accelerate i have valve ticking noise, but i check my compression its fine. Feelings like you pulling the trailer or 15 people in the car. Its not slipage. I not havig problem with starting the car. Starts like new. If you interested what else was changed you can find in "NO CAT".
Only things wasnt changed yet is: EGR, crancshaft pos sensors, camshaft pos sensors. But i dont think its can cause the problem.
Thank you very much for you help guys.

Spray carb cleaner around injector base,and intake manifold. If this smooths out the engine fix the vacuum leak. Pinch off the hose to the brake vacuum booster use channel locks if this smooths out the idle get a rebuilt unit. Clogged injectors cause lack of power mostly but can cause rough idle.
Most coil problems can be checked with a scope does your shop have one.
Use an ohm meter and check each plug wire for continuty loose end on the wires cause a lot of problems I have a crimping tool for them. Many times people buy cheap plug wires and they don't crimp them correctly. You can purchase a small screwdriver with a bulb in it at a parts store watch it flash
watch brightness. You push it in beside the boot.
Look at your haynes manual it should show you how to ohm a coil and the readings.
Put 12 volt on the positive the neg. should read over 11 volt if not grounded.
Check the pressure regulator if gas is in the vacuum line replace. Pinch off the return line in the rubber line does the engine have more power.

Primary resistance for coils small chevy's 0.3 to 0.7 this is across plugs at the bottom.
Secondary resistance 5,000 to 6,500 ohms this is across the towers

Thankyou good info. I put seafom today les see what happen..
is this looks fine to you.:
coil 1/4 on the pins 5,73 kohm, bottom 0,8 ohm
coil 2/5 on the pins 5,74 kohm, bottom 0,9 ohm
coil 6/3 on the pins 5,76 kohm, bottom 0,9 ohm
Can you tell me how should be this coils if you looking from the front of the car from generator (left) side. And plugs, rear and front rows from the same side. I just asking because some times you gonna put wrong and didnt know that. I am asking firing order and locations.
Because i heard people saying if you gonna swap around wires, its not gonna trow the code, (basicaly they right) cause all plugs gonna fire just not exactly right time.
Thank you

Btw forgot to tell you that i checkd vacuum lines with foam and find nothing.
And i check egr too. I thought its stuck open.But it was fine.

Btw forgot to tell you that i checkd vacuum lines with foam and find nothing.
And i check egr too. I thought its stuck open.But it was fine.

3.8?

3.4

Towers towards the front. 1-4,2-5,3-6 2 elect plugs right 1 elect plug left

Try Cleanind The Little Wires On The Maf Sensor be Carful

Thank you. I am gonna take a look.

Do You Use A K&n Air Filter?

Coils location i think you gave me wrong. 1-4,3-6,2-5 thats what i have. I tried your way my car didnt start. I am already on half a tank with seafom and no changes. I have major loss of power and hard shifting. And i do not think this is not trany problem, its like cat symptoms. From 1-2 you can feel harder shifting than 2-3 and less when 3-4. Its because bad engine operating, but i dont know.

355smallblock
Maf sensor is new ACdelco, but i never chack the connector. I am pretty sure nothing wrong with it.

typo 1-4 ,2-5 ,3-6 sorry about that Haynes 1995 thru 2000 Lumina&Monte Carlo

You have any clues what else i could be?

Surely when you changed the wires you noticed a difference as the module sends the signal to the coils. I listed them 1-2-3 so 4 plugs would be firing differently. If this didn't help reply.

Yes it was like 2 cilinders working only. Was a very hard start and backfire.
I have ALLDATA and i found firing order and it looks like mine exactly.

Good so it it working fine at this time.

Did you ever heard that resonator or mufler can be cloged very much? And cuase bad cat symptoms.

Yes, mostly debris fom a bad cat gets caught in the muffler.

Forgot to tell you, i dont have a cat right now and i put 02sim. What i did month ago i removed 02 sensor (cause it only like a plug right now) and did trip around the block. Almost no changes. Or this is not the way to check that.
Can this be involved, cause those hard to change: Crancshaft sesors and Camshaft sensors.
This only sensor wich i never touch, all rest of them was changed on OEM.
If you have more question go to "NO cat" bottom of page.

Drop the exhaust down and see if it runs better.

What you mean drop it down? I dont have a lot of money for experiments.
I thought its gonna stuck in resonator then in mufler. And how i can test my self what is that exactly?
Thank you

By "drop the exhaust down", Max is suggesting you disconnect the exhaust to see if it is restricted and causing your issue.

I have 03 impala, with 3.4 L and on avarege i get about 18 mpg... with 106.000 miles...:banghead: