clogged-dirty-varnished injectors? or NO?

[Clark]

Here's the rundown:

The engine is an LQ9 from a 2004 escalade. The intake, fuel rails, and injectors have been sitting for 4+ years. It has a new fuel system and fresh gas upto the fuel rail.




Here's the problem:

Finally fired off for the first time, but it took awhile, and when it did start it's rough, and you have to hold the Throttle open to keep it going. Smell of bad gas. Plugged in a scan tool and not throwing any codes.






Here's what i'm thinking:

The left over gas in the rails/injectors has varnished up and gunked things up.







Before i clean/replace the injectors does anyone have any idea's on what the problem might be besides this? Or maybe someone has information suggesting i'm on the right track? I don't want to spend $250 cleaning the injectors and it does nothing.

 

[crash2]

Replace the injectors and blow out the fuel rail. Some of the newer ones are not cleanable..

Not the first time I have seen this....

 

[Clark]

how would i know if i need to replace them or if i can take them somewhere like dr injector and have them cleaned?

 

[crash2]

There is one way clark. Pull the fuel rail up. Pull the connectors on the injectors.

What you need to do is pressurize the fuel system and made a small cup you can stick under the nozzel of the injector. Then what you want to do is run 12v/ground to the injector (with the fuel pump running) for a set amount of seconds (like 4). Do this with each injector and compare the amount of fuel.

Now this is only a rough idea because even with some fuel flow you will still get a lean miss.

 

[skinny_pedal]

Im not familiar with this style injector but you can usually just look at a injector basket and tell its life story. We had am injector machine at my last shop. I got good at injectors

 

[Clark]

SUPRISE! The injectors could still be dirty. BUT after checking the coil packs, the harness was on backwards, causing the firing order to be off. It runs ****ing tits now!

 

[stealthrunner1]

SUPRISE! The injectors could still be dirty. BUT after checking the coil packs, the harness was on backwards, causing the firing order to be off. It runs ****ing tits now!

Glad it was a easy deal to figure out Clark!!!!!
I'm still trying to figure out why my Ls-1 ...won't. Run tits with both O2 sensors pluged in...the ap i have on my phone says that with one O2 pluged in..it is doing its job!!! Then when you plug the 2nd sensor in it will make the oher sensor start dumping fuel into the motor!!!!! We will figure it out sooner or later......but help is appriciated!!!!:awesomework:

 

[Clark]

Are your o2 sensors new? What harness are you using? What isn't stock on the engine? I've got efi live if you think you can utilize it. Let's figure it out so you can wheel too.

 

[TreeClimber]

FWIW, I'd replace both the 02 sensors with new ones, and re-test.

 

[crash2]

No---watch the data before simply throwing parts at something....

 

[zukkev]

No---watch the data before simply throwing parts at something....

This...but if you don't know what to look at, it's kinda like the deer in headlights syndrome :yikes:....at that point people think Shotgunning is much easier! :squirrel:

 

[stealthrunner1]

Sorry to hijack your thread Clark...but...has two new Delco sensors...runs good on the one you can see the one sensor doing its job correctly numbers wise...but when you plug the other one in it s setting goes off the scale and reads .85 ish insted of .02 ish on the one plugged in and doing its job correctly!!!:eeek: The harness was modded by the guy that built the motor and programmed the computer also...

http://rodscars.net/

here's his site..:awesomework:

 

[Clark]

i would probably buy a new harness from, and have your ECM tuned by nutterracingengines they are on craigslist, type in ls1, or try nutterracingengines.com

Then sell the old harness and recoupe some $$.

But i hate screwing around with **** that has wierd bugs and someone else built, and i can't tell you what they did.

I can't think of anything that would actually help fix what you have going on, except maybe check the two sensors aren't some how wired together in the harness, and check the engine has a good ground, something on backwards, look up some pics on google image of modded harness, and get on ls1tech.com or other ls1 websites.

GOOD LUCK BUDDY!!!!:beer::beer::beer: