Fuel Injector Questions *pics inside*

Well after finding the first fuel injector on the rail leaking I decided I needed to take them off and replace the o-rings.

I took the injectors off of my parts jeep, I bathed them in b-12 chemtool, it really took off all of the crap that was on them. Was it safe to bathe these injectors in it? It did a real good job of cleaning them off. The first set is going to be the 1st picture

I planned on using one of the parts injectors to replace the one that went bad. So I took off the injectors on the jeep i'm working on. The second set of injectors that I took off are alot larger. Could these be the 19lb injectors? The big injectors are the 2nd picture.

http://www.members.tripod.com/daniel7310

I can only tell you they must all be the same.

The parts injectors don't even match each other, much less the ones you have

If you are going to pull stock injectors, at the least you should make sure the model year of the donor is in the same category as your primary on the following chart

http://www.jeep4.0performance.4mg.com/tech_specs.html

delete

Provided they're both the same era of Jeeps I'd be inclined to say that one of them has had the injectors replaced. According to your profile your running Renix XJ's. The half metal half plastic injectors look exactly like my OEM units did; they leaked (the plastic and metal seperates). The all plastic injectors look exactly like the replacedment injectors I purchased a few years ago. They were stock rated injectors from a parts store, if I recall the brand was GP Sorensen (or similiar...?)

Sequoia

Having slugged it out with O-rings cause of fuel leaking all over the manifold, after having replaced all the O-rings, after start up, they weren't leaking, the injectors were. For a fuel leak along the rail, one MUST make sure the injectors themselves aren't leaking. If they are, then, my recommendation, is to replace only with NEW injectors. They typically have lifetime warrenties and they come with new O-rings.

I noticed that the second set I pulled didn't match. There were 3 big ones and 3 normal size ones. Thanks for bringing that up langer1 and lilredwagn.

I ended up using the 3 bigger type and 1 of the originals along with 2 cleaner looking donors. I'm still running the 3/3 mix. Why do they all have to match? I've had this jeep for over a year with no leakage or problems of any kind. I haven't had any problems yet, either.

The reinstall went good. I heeded alot of advice that I searched.
Bathing the injectors in B-12 really did a good job of taking all that junk. I let the o-rings soak in gas like I read in someones post. So far....so good. I've driven about 100 miles today checking the injectors regularly. No leaks, and I feel a noticible difference.

The only reason I didn't go ahead and just replace the injectors is because i'm flat broke, and i've got no credit. I'm hoping on redoing them with the 5.0's soon, but for now i'm happy.

They need to match so that all cyclinders recieve the same amount of fuel.

Obviously they have to match in terms of flow rate, etc. but I don't see why you couldn't mix brands or ages as long as they're the same specs. It's always risky reusing original Renix injectors because, as Daededgewood points out, they can be a real PITA about leaking from the body or the connector. If I were doing this, I'd try to figure out which of the mismatched set are replacements, and which original, and use the replacements.