Fuel injectors....HELP!!!!

[BillyGman]

I'm installing bigger fuel injectors, and the new ones (also Motorcraft) all have a whitish clear plastic ring around them on the end that goes into the intake manifold. But the original ones do NOT have that. This isn't a cap, but a ring w/a hole on the center of it.I'm getting a whole bunch of contradicting answers on this. Can anyone tell me if this has to be taken off? It seems like it would require a good deal of force to pry these things off, so I just don't know if they are really protective pieces, or if they're supposed to stay on there. I don't want to damage these things trying to remove them if they're not intended to be removed.

I've called three Ford dealers about this, and nobody can give me an answer. Furthermore one mechanic told me that they have to come off, and the place where I bought them from told me that they have to stay on!!!! :confused:

These plastic rings do NOT cover the O-ring. They are very narrow bands, but I just don't see why the end of a fuel injector would be made of a clear plastic since they're exposed to heat. Someone else told me that they have to be removed because the injector will not even fit in the intake manifold holes if these plastic pieces are left on, but they DO fit in there w/them on.

[Ross]

Billy, I'll be watching for the answer to this, as well. In the meantime, are you just installing bigger injectors, or are you doing other things like different fuel pump, etc? If you are just doing injectors, do you think you will need some computer tweaking to get them tuned right, or should they work OK by themselves? This is interesting to me.

[darebren]

yeah, what he said. I'm interested in the details behind this one. Can you get any dyno info to see if they help? and what poundage did you go with? and software... I would think the ECM could adapt to these without upgrade? When the new K&N FIPK kit comes in, more air will mean more folks getting bigger injectors to compensate...

[TripleTransAm]

I would think the ECM could adapt to these without upgrade? When the new K&N FIPK kit comes in, more air will mean more folks getting bigger injectors to compensate...


Stock injectors should be able to provide ample fuel delivery until you get to serious mods. An FIPK shouldn't require injector upgrades... I have a hard time believing the stock injectors are close to being maxed out.

Billy, why the change in injectors?

Oversizing injectors for a given application can actually bring on more problems... injectors work best when they are slammed open and shut. The time they are operating between full open and full closed is actually the undesirable area of operation, and the PCM takes this into account (ie. I'll hold the injectors open this long because I know the actual opening and closing will result in improper fuel atomization). Too much fuel delivery during the ON cycle (ie. due to big injectors) can result in the injectors spending more time in the opening/closing phases instead of in the full-open portion, and this results in very poor air/fuel mixture control. Most of the time, the motor will be out of control, mixture-wise.

[MikesMerc]

Stock injectors should be able to provide ample fuel delivery until you get to serious mods. An FIPK shouldn't require injector upgrades... I have a hard time believing the stock injectors are close to being maxed out.

I agree. There is plenty more headroom in the stock injectors. Most can handle the increase in power that a modded exhaust, new/improved intake, and throttle body provides combined....let alone a simple FIPK change. A swap to bigger injectors is only needed when heads are changed/modded, or a significant power adder is applied.


Oversizing injectors for a given application can actually bring on more problems... injectors work best when they are slammed open and shut......Too much fuel delivery during the ON cycle (ie. due to big injectors) can result in the injectors spending more time in the opening/closing phases instead of in the full-open portion, and this results in very poor air/fuel mixture control. Most of the time, the motor will be out of control, mixture-wise.

Very true. Oversized injectors will kill performance. You always maximize your current injectors before going to the next level.

Do I smell a power adder there Billy? :D

[BillyGman]

[b]Do I smell a power adder there Billy? :D

...LOL....okay, okay.....yes Mike, your nose is correct on that one. I didn't mean to throw you guys off the trail, but yes I am in the middle of a S/Cer installation, thus the reason for the bigger injectors. ;)

[Smokie]

For each fuel injector, wiggle it a little and it'll pop off. Each one will squirt a little gas, so this isn't the best place to take up smoking. Replacing them is easy -- pop the new injectors back in place. Be sure to put a little lubricant (we used 20-weight engine oil) on the O-rings.

Leave the protective caps on the fuel injectors until they are in their final position. Get the fuel rail and injector assembly positioned to nearly where it has to go; just before pushing each injector into place, remove the cap and lubricate the O-ring.

Billy I hope this helps.

[BillyGman]

The plastic rings I'm talking about do not cover the O-rings. So I don't think they're what you're talking about Smokie. I left them on since that's what I was told to do.

[MAD-3R]

The plastic rings I'm talking about do not cover the O-rings. So I don't think they're what you're talking about Smokie. I left them on since that's what I was told to do.

Get it in Writing!! :)

[BillyGman]

For clarification:

Some of you seem to think that I'm talking about a simple plastic sleeve or cap like the ones you would find on some brands of sparkplugs when you first take them out of the box. That would be a no-brainer. Ofcourse things like that have to be removed before installation. That's obvious. And yes, some injectors I'm told do come packaged w/similar plastic caps or sleeves that are just for protection. I don't need instruction from anyone to know that things like that have to be removed before installation.

But w/the injectors I've installed, that is NOT the case. These are plastic RINGS that are on the end of the injectors and are not caps, nor sleeves. They have a hole in the center, and appear to actually be part of the injector itself. They would NOT come off as easily nor as quickly as the sleeves that come w/sparkplugs which are there to protect the threads of the plug. The plastic piece I'm speaking of would literally have to be pried off of the injector w/a screw driver.

What threw me off about this, is that the old ones do NOT have that plastic piece on the end of them like the new ones do. So I wasn't sure about exactly what these things are.

[SergntMac]

...LOL...okay, okay...I didn't mean to throw you guys off the trail, but yes I am in the middle of a S/Cer installation, thus the reason for the bigger injectors.
Yes, you did, Billy.

At the very least, I can look forward to a change in your sig.

[BillyGman]

I was just trying to avoid this---> :argue:

[Katmandu]

What # are OEM MM injectors anyways ??

[BillyGman]

I for one can't even tell you. I think I tossed my original ones out. But allow me to explain to everyone that those plastic rings on those replacement injectors didn't have to be removed like the plastic caps do that come on some other injectors. These weren't caps. just rings, and they're actually part of the injector.