How hard is it to clean and/or replace injectors?

[jwanck11]

Mine is at a marina at the moment. The tech said 4 cylinders are leaning out bad. Pumps test good and the injectors feel like they are pulsing. The gas looks like crap (sat too long with stabil in it). My best guess is the injectors are clogged (the tiny screen) and need to be cleaned and/or replaced if cleaning does not work.

The cost he quoted to pick up new injectors was ridiculously high.

If this is not too hard, I am considering asking him to reassemble stuff, bring it home and do it myself.

Thoughts??

'0422i with a 5.7 335HP Marine Power.

[Ewok]

Try a fresh tank of gas treated with seafoam if able.

[boatwakes]

The injectors are very easy to replace and are about $120ea from injectorwarehouse.com. You must also replace the orings, two per injector. OEM orings are about $3ea or felpro number is es70599 (4pack) for $4. Lube the new orings prior to installation in the manifold and then prior to installing in the rail.
However, if you screw up, you can blow up. Leaking injectors are possible from incorrect installation so let us know if you want the full guidelines and I'll pm them to you.

[jwanck11]

Boatwakes, thanks!!!

I definitely do not want to blow up. lol

Yes, If you can PM me guidelines, I would greatly appreciate it.

Also, can you provide a perspective on trying seafoam first? I would certainly like to try a low tech route over the high tech route if that is a viable path.

[TeamAllen]

I have a friend that sends his out to be cleaned and check the flow balance. I'm not sure this is the company he uses, but it gives you an idea of the possibilities.
http://www.proflowtech.com/

[boatwakes]

Ive got a couple questions for the tech: how does he know they're leaning out? are they all on the same side of the engine? If so, there's a root problem of fuel flow between rails. Sea foam is great and injector replacement usually isn't the issue. I've had to replace 2 injectors in over 15 years of doing this and the injectors I replaced were cracked from the last idiot who put the rail on incorrectly.

[jwanck11]

Thanks! No, happening on both sides apparently. Though I believe he said it was more cylinders on one side than the other. Not sure what he used to test. He did say he could feel them pulsing.

I had very old gas that had both winter stabilizer as well as the ethanol stabil in it too. I had the gas filter replaced and when I ran it, it ran like crap under load. In neutral, the engine revved very nicely. Under load though it was horrible and audibly knocked. I immediately just idled back to the ramp. He has had it since.

I am at the point of just grabbing it and running seafoam to see if that addresses the problem. I do have to get rid of the gas and need to find where I can do that.

[boatwakes]

WOW!!! Okay, find someone who has a diagnostic computer and/or an injector tester. Pull all the spark plugs and label them as they come out, 1357 on the port side and 2468 on the starboard. Compare electrode tips to one another and check out lean condition spark plugs online but every injector "pulses" and that has no bearing on lean or rich condition. If you get a computer on the engine you can determine what the injector "on time" is when then engine is cold and then warm. Cold should be no more than 4.5 milliseconds and warm (over 145*) should be no more than 2.5 milliseconds. BTW, gimmie your serial number from the engine because if you have the "crab cap" distributor cap, I will have you change that first, thousands of problems with that damn cap that present the same way.
Actually, if you could take a picture of all the plugs side by side and post them.