Injector problem

[NewBoost1997]

Hey guys. So I'm getting a misfire on cylinder one. I've done and checked all my ignition and thts all good and working right. So I'm think it is an injector. I'm doing a pulse test on it today. It if is bad I'm going to do all 6 injectors. Would it best to put stock injectors back in (because I don't have time and money right now to mod because of college) or should I put a littler bit higher pound injectors in? Let me know. Thanks

[Fivefingerdeathpunch]

Stock injectors.

So the plugs and wires and coils are all good?

What brand plugs and gap?

[matt5112]

stock unless you plan on adding a cam/intercooler/E85.

[NewBoost1997]

Plugs are .6 gap I believe. Plugs wires and coils are good. Everything is literally stock except a CAI I built for it. What pound injector would you recommend

[matt5112]

0.060" right?

Well since you didn't mention any modifications, stock injectors are fine.

[NewBoost1997]

Yeah all stock :/.

[NewBoost1997]

Stock is like 22. Should I get zzp 24 or 26 or 28?? After that it's 33, 42.5 and so on

[matt5112]

Is it supercharged?

If so, you have 33's.

[Fivefingerdeathpunch]

Stock L67 injectors are 33lbs, Im pretty sure.

[NewBoost1997]

Wtf. Someone told me 22. Haha. I also used that whole "math equation" for it and got 22. Haha wow I feel like an idiot

[BillBoost37]

If you need an injector and want to save money..replace the one bad part. They aren't all bad.

[NewBoost1997]

I am probably going to do them all. I can get zzp injectors for a decent cost

[blueguy]

Just replace the one.

Or, swap them around to another cylinder and see if the misfire follows the injector.

That's free.

Don't go spending money on crap you don't need.

Only thing I could recommend, are new injector o-rings...top and bottom.

[Grandprix27]

Usually when you try to replace the O-rings on the bottom of that fuel injector, 99.9999999% of the time you'll break the brown plastic piece right below that O-ring, so you'll have to replace the whole injector at that point. Im guessing that yours has never been change? Which isn't necessarily a bad thing, cause they are meant to last the lifetime of the vehilce... in most cases. But if you're planning on buying some, really all you need to do is replace the bad one, don't get into a habit of buying stuff you don't need. What happens if the injectors aren't your problem after you've replaced them all? Then your out hundreds of dollars... Couldv'e used that money to fix the problem, you know? Or something else more important. At the end of the day its your money, Im not gonna be the one to tell you how to spend it. Just try to help you to not make the decisions I have made from buying things I didn't need. Also don't over look sensors, sometimes they can cause misfires also. Its rare, but it does happen. FiveFingerDeathPunch is right...(Your stock injectors are 33lbs)

[blueguy]

The hell?

I never had the brown plastic pieces...you don't need them.

So, just remove the ones that are broken..and if you don't break them...then its not a big deal. Not the end of the world.

[Rico]

Hey guys. So I'm getting a misfire on cylinder one. I've done and checked all my ignition and thts all good and working right. So I'm think it is an injector. I'm doing a pulse test on it today. It if is bad I'm going to do all 6 injectors. Would it best to put stock injectors back in (because I don't have time and money right now to mod because of college) or should I put a littler bit higher pound injectors in? Let me know. Thanks

Pulse Test?..You mean test for PWM (duty cycle = PW/wave period X 100%) from the PCM or remove the injector and pulse it with 12V to see if it sprays?

Testing for PWM from the PCM will only tell you if the commanded signal exists and has nothing to do with the injector's condition.
Removing the injector and applying 12V while pressurized with fuel (or carb cleaner) is a quick way to check the injector.

Most of the time the injector just needs cleaned. Using carb cleaner like in the spray test above should clean it up.

[TheYanz]

Hey Rico that sounds pretty cool... U ever do that? How would u rig up the carb cleaner to be pressurized? Perhaps use a bigger vacuum tube from a parts place & rig it up good on the carb cleaner nozzle & then on the injector port? How'd u do it? Did it work well in terms of cleaning the waxy sh*t out that builds up??? Wat about a good 12V source for all this??? Another question... Do GTP injectors actually "spray" out in cone shaped mists or is it more like a stream/ jet that's supposed to shoot out if everything's working normally? I had them flowbench tested last summer * they didn't seem to "spray" but the f*ckin guy said "No that's normal they don't always actually "spray" out like u see on the web vids"... Hm... ???

[Slick2500]

Why did you resurrect this thread to ask the same question you already asked in your own thread that you made?

[matt5112]

see your thread.

[Rico]

Hey Rico that sounds pretty cool... U ever do that? How would u rig up the carb cleaner to be pressurized? Perhaps use a bigger vacuum tube from a parts place & rig it up good on the carb cleaner nozzle & then on the injector port? How'd u do it? Did it work well in terms of cleaning the waxy sh*t out that builds up??? Wat about a good 12V source for all this??? Another question... Do GTP injectors actually "spray" out in cone shaped mists or is it more like a stream/ jet that's supposed to shoot out if everything's working normally? I had them flowbench tested last summer * they didn't seem to "spray" but the f*ckin guy said "No that's normal they don't always actually "spray" out like u see on the web vids"... Hm... ???

To clean the injectors I use silicone tubing from work and Zip ties. It takes three different tubing sizes to go from the red tube that comes with the carb cleaner up to the inlet of the injector.

For power I have a variable DC power supply (rated 0 to 30V @ 5 Amp) but you can use a car battery or any other 12 V source.

Hold the nozzle on the can until it builds up pressure and pulse the power to the coil on the injector. I usually do about 20 squirts and then one long blast for about 20 seconds. You can also back-flush the injectors in the same manner.

The injectors have 4 pin holes where the fuel comes out. Each port interacts with the others to create cone shaped spray. This helps with atomization. The size and shape of the cone may vary depending on the application. This is necessary for performance and efficiency.