Leaking Fuel Injector | Replacement! | Hummer H3

Leaking fuel injector replacement made easy on a Hummer H3. My injectors were not leaking, but I decided to upgrade to better ones! Hopefully this informational guide can be of help in resolving leaky fuel injector problems. Consider subscribing!
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Products!
2006 3.5L injectors: amzn.to/3g86IBP
2007 3.7L injectors: amzn.to/37QLzYx
2008 3.7L injectors: amzn.to/3kfTIf1
2008-2009 5.3L injectors: amzn.to/3AH6d9M
2009-2010 3.7L injectors: amzn.to/3jZfljl
2010 5.3L injectors: amzn.to/2UkMnSc
H3 HUMPER is an overlanding machine made for adventure. Here are the stories of nursing this rig back to health during the pandemic road trip.
#LeakingFuelInjector #HummerH3 #FuelInjectorReplacement

[@robmitchell2018]

Fantastic video! This is to the point with necessary detail. Thank you!!

[@H3Humper]

Hello Rob, thank you so much! I do my best to keep these videos concise. 🤓

[@meltingpoint2458]

I'm glad your on here making Hummer H3 videos. Im DIY guy and do everything myself but i always watch videos to have tricks or tips. Finding stuff for Hummers is hard, its nice knowing your videos are up to date and very well explained. Thank you for taking time out of your day to make videos like this.

[@H3Humper]

I really appreciate your words 🤓 My hope is to contribute to our DIY-style knowledge base and I'm happy to know you find the videos useful. Thank you for your comment! It's encouraging to receive and helps stir up some motivation to make more videos.

[@gregpayrastre]

Super merci beaucoup - je vais bientot devoir faire cette operation car j'ai une defaut P0304 ! les bobines et bougies ont été changees - reste les INJECTEURS -

[@djcon]

Awesome video! Very well shot edited, and hearing the snaps and clicks was very satisfying! Great job!

[@H3Humper]

Thank you so much! I am happy to know you enjoyed the video! 😎

[@KarpisMaksudian]

Awesome video. Thanks

[@H3Humper]

Hey Karpis, you're welcome and thank you! 😎

[@DJH3]

I just did this on my 2008 H3 and I have absolutely no idea what sorcery you used to be able to get to all the intake bolts without having to go through the wheel well! I actually tried to start by going in from the top like you did but quickly abandoned that idea! I was at it for probably 4 times longer than you were as well, lol.

[@H3Humper]

I use my go-go-gadjet extendo arms to do it from up top haha. I'm pretty tall and my arms are like spaghetti noodles, which makes it a bit easier haha.

[@TXH3]

Great video!

[@H3Humper]

Hey Benjamin, thank you!

[@tomfrantz]

Thank You!

[@digitalwayanenetwork1056]

You are the best !!

[@H3Humper]

Thank you! ☺️

[@jacobkeller5854]

Great video! How did you connect the pvc hose to the rubber coupler?

[@H3Humper]

Hey Jacob, thank you! I connected the PCV hose to the coupler using a section of an old spark plug as the "nipple" on the coupler. I cut the top half of the plug off using a grinder (leaving just the threads and a small ring just below the "bolt head" portion of the plug). I cut off the ground electrode (the metal L-shaped thing at the bottom of the plug). I connected this DIY nipple to the coupler by drilling a hole with a spade bit (for wood) and then fastening the nipple to it using a very tight fitting nylon washer and some RTV. Then I fastened the PCV hose to the nipple with a hose clamp. It is a one-and-done sort of setup (I don't disconnect the joint at the coupler to avoid damaging the integrity of the seal) haha. So far it still hasn't leaked at all, which is great! I smoke tested it with a DIY smoke machine.

[@HummerH-mo4cs]

1. Hello and Thank You . 2. Do you know what the little valve looking thing is that's on the Aluminum tubing leading INTO the Fuel Injector Rail. About 3" from the rail end on tubing. At 3:15 you can see it sticking down, looks like your black cap is gone ??.... NOT the A/C one. Can I use this to blow cleaner into injectors on rail to clean them, with out ANY Dismantling ???? Of course I would pull the fuel pump fuse... 3. " upgrade to better ones" injectors that is, what did you end up going with ?? Thanks again for all your Time and knowledge :)

[@H3Humper]

1. Hello to you, and my pleasure 🙏 2. The nipple on the fuel rail is the fuel pressure check valve, and very clever idea with injecting cleaner there 😎 I think it'll work great! kzbin.info/www/bejne/qaWohah9ed-imtU 3. I "upgraded" the injectors from the original "early ls-truck" type to the "late ls-truck" type 🤓 "upgraded" in the sense of a higher flow rate and a more modern design kzbin.info/www/bejne/jGSugqmMrbqia6c You're welcome, and thank you for sharing your ideas!

[@adamcnow]

Great video! I have a bad injector. Did you reuse old intake manifold gasket or get new one! Throttle body gasket reuse or new?

[@H3Humper]

Thank you! I replaced my gaskets just for the sake of knowing they are fresh, but they can be re-used if they are not hard, brittle, or damaged. If you remove them and they are still soft, I imagine cleaning them with some soap and water will freshen them up for re-using.

[@adamcnow]

Thanks! yeah I was thinking the same.... get new ones.

[@H3Humper]

@@adamcnow it's nice to know they're fresh in there but also nice to save money and reduce waste!

[@signals34]

Did you have to pull fuses before removing rail...fuel pump and injector fuses?...start the car until it dies , to relieve the pressure?...anything else?...thanks...

[@H3Humper]

Hey there, I can't remember which route I used, but using the fuel pressure check valve to release any residual pressure would work. This could be done using the release valve on a fuel pressure tester or simply using a rag and something to depress the valve stem). The fuel pressure should be close to 0 PSI if the key has been "off" for a decent period of time (a couple of hours or so). Disabling the fuel pump and letting it run until it dies works, but it also "leans" out the engine before it stalls, which can cause damage (though very unlikely).

[@bma4203]

“If it ain’t broke don’t fix it”!

[@H3Humper]

Great tip! 🤓

[@paulnightwolf9043]

Do you need new intake gaskets and throttle body gaskets when you replace these Injectors

[@H3Humper]

Hello Paul, I believe the shop manual recommends new gaskets but you should be able to re-use your old ones if they are not damaged. 🤓

[@signals34]

whats the best stuff to use to put in fuel tank to clean clogged injectors?....i think thats what my problem is....if not, next step is to replace injectors....thanks !!

[@H3Humper]

kzbin.info/www/bejne/qaWohah9ed-imtU this is how I cleaned out my injectors really well!

[@LatvjuAvs]

Thanks. How many hours ~ went into this process?

[@H3Humper]

Hello Latvju, I would estimate one to two hours of time if following the video closely. The most challenging part for me was removing the intake manifold. The images I have included in the video show exactly where the bolts are on the intake, which should save a lot of time! Are you replacing your injectors?

[@LatvjuAvs]

@@H3Humper Not replacing yet! But knowing that truck has its age, everything falls apart slowly, so got to know estimates how long to spend cursing at stuck and broken bolts eventually :)

[@H3Humper]

@@LatvjuAvs Understandable! Getting an idea for time is always nice. Things always end up taking me 4 times as long as expected for those reasons haha.

[@NickSchoess]

yesss

[@H3Humper]

[@jaygillian7442]

Would have been nice if you showed how to remove the belt. That requires a special tool and instruction on how to use it would be helpful.

[@H3Humper]

Hello Jay, I use a 3/8" drive ratchet to relieve tension from the belt and remove it. For extra leverage, I slide the loop end of an adjustable wrench over the handle of the ratchet. I'll add an updated video on my method without the special tool 🤓

[@ilost7489]

There's a square slot in the tensioner where you can put a ratchet to take tension off the belt

[@rizkybiss]

Notice any difference after changing the fuel injectors? If so what is the difference? Does it idle better? How hard was it to take off the intake manifold? It looks like a pain in the ass. Any problems after removing and installing it? I want to do the same thing but I'm worried about messing up the intake manifold

[@H3Humper]

Hey Riskybiss! I did not notice any difference at all so far. I actually switched to injectors with a higher flow rate so I can hopefully get a little bit more out of them with tuning. Still tracing down my crank no-start issue in the meantime, though. The intake manifold was definitely the part I was least comfortable with! I have removed the intake manifold twice now and feel a lot more comfortable around it now. As long as you get all 9 bolts loose and don't pry on the intake manifold, you should be good. Some have a small metal bracket on the bottom (for wiring harnesses to "button" on to) which needs to be removed with 3 more small bolts. I am working on an intake manifold gasket replacement video right now. It's really hard to show the process because the bolts are in a very tight space. With a single ~6 inch extension, the job is pretty quick. I would say maybe 30-45 minutes before getting the manifold off.

[@rizkybiss]

@@H3Humper right on. I have a second intake manifold in my garage for when my motor was replaced. For some reason they put the intake manifold off of my 180k engine and put it on the newer engine. But the one in my garage only has 90k on it and I'm wondering if I had problems with the old one so I want to put the newer one on when I do injectors.

[@H3Humper]

@@rizkybiss Interesting! I wonder why they did that. It'll be nice putting the newer intake on there and an opportune time while doing injectors, for sure. My intake manifold has some external damage and I considered replacing it with an intake I found at the junkyard, but I figure I'll just keep using mine until it cracks or something. I wish the intake were easier to remove on these things lol

[@cflip7452]

@@H3Humper you referred to the no crank issue! Just a heads up anytime you take of the serpentine belt you’ll notice the exhaust camshaft position sensor wiring harness is in arms way when trying to reinstall serpentine belt and easy to mess up contacts. The reason I know this is I had a similar problem and found that when reinstalling serpentine belt you’ll put pressure on wiring connection at least this is what happened in my case and it was my problem on 2007 Hummer H3. Problem solved after I replaced wiring connector to exhaust camshaft sensor. Just something to take a look at👍. Great video by the way

[@H3Humper]

@@cflip7452 Thank you for the tip on the exhaust side cam harness! I noticed the connector on mine is a bit loose, so I'll look into it more. I finally fixed my crank no-start, thankfully! It ended up being a poorly positioned intake cam sensor installed by the previous owner when doing the 3.7L swap. I had to do some drilling and grinding to get it properly positioned

[@hassanliebherr1270]

Hello my friend... I have a HUMMER h3 2007 3.7L and I have a problem with the engine cutting, weakness and vibration of the engine and I want to change the injectors according to an examination and it was found by Injector No. 1 that is not working properly I want the correct number of the injectors because a year ago I changed them and the problem went away but unfortunately it came back and the reason Injectors, so I want original ones. What is the code for the HUMMER h3 2007 3.7L, thank you

[@H3Humper]

amzn.to/3GTkHKh Hello Hassan, here is the OEM injector for your 2007 3.7L 🤓 Having the issue come back is unfortunate... While you have it apart again, I recommend checking the wiring harnesses for any damage to make sure it's not causing any issues, as well.

[@scotnielsen7685]

Skipped over quite a few details getting to the fuel rail... removal and installation of intake bolts are much easier accessing through the driver's side inner fender

[@H3Humper]

My H3 was missing a bracket during this video, which may be what you've noticed. I prefer removing the intake bolts from the engine bay, myself, but have heard a lot of people prefer the fender route. Thanks for sharing!

[@markwarner6631]

Doesn’t motor oil corrode an swell o rings

[@H3Humper]

Hey there Mark, I did some searching and found mixed answers. I see petroleum-based products can indeed swell rubber o-rings. It looks like a safer option might be vegetable oil, silicone lubricant, or other non-petroleum based oils. My intention with using oil for the install is to prevent the o-rings from catching on their seating areas leading to slicing, stretching, or tearing of the o-rings. I have used synthetic oil to lubricate most of my o-rings (on other vehicles and engines) and have not noticed any issues so far. I am interested in what the manual would recommend using for installation. I'll try finding an answer and will update you with what I find. What lubricant do you use on o-rings?

[@ramiroreyes-hz8lw]

Tencks

[@H3Humper]

You're welcome!

[@EurynomeStolas]

how do you know that this is a problem?

[@H3Humper]

If the fuel injector is visibly leaking when the fuel railed is removed and pressurized, a person can determine it is leaking. Another way is to pressurize the fuel rail side of the fuel system and check for a significant pressure drop. I didn't explain these too well with the video, unfortunately.

[@cloudrhezii]

What made you know it was leaking ? I have a misfire on cylinder one confirm compression is good and spark switched coils and plugs this is the next thing I’m thinking

[@H3Humper]

To verify a leaking injector, I pull the fuel rail with injectors attached. Then, I turn the key on with engine off twice for four seconds each (to pressurize the fuel rail). If the fuel injectors or seals are leaking fuel, this indicates a leaking injector. Additionally, connecting a fuel pressure gauge to the check port and watching for a leak down could help diagnose the leak. There is a method in the repair manual in which a person could model by pinching the soft part of the fuel line in the engine bay with a soft clamp of some sort after allowing for pressure to build, and then checking for pressure leak down between the clamp and the fuel rail, which would either indicate a leak at the fuel rail/injectors or leak at the clamp. Your issue could be related to a freyed wire supplying the coil pack. I suggest paling back the wire conduit to inspect the wires from the coils back to the harness. I've heard of a few people having issues with freyed wires in such a way and it would certainly be a possibility with your misfire symptoms.

[@cloudrhezii]

@@H3Humper I figured it out a little bit ago I took a injectior off the old engine and switched it seems to have fixed the problem! Thanks man

[@suriyadinesh5272]

mileage Per gallon

[@H3Humper]

Hey Suriya, I currently get around 22 MPG but am trying to tune to get better mileage 😎

[@ivan_germogenovich]

@@H3Humper, Hi! what is the structure of your car's mileage? % in the city, in the village, on the highway ... I get about 19 mpg, I drive mainly in the 2M city ... So I wonder if I need to check the fuel system or not? Thank you.

[@H3Humper]

@@ivan_germogenovich Hello friend! On average I get: 18MPG in city/village and up to 22-24MPG on the highway. I drive very slowly, do not accelerate fast, drive at high elevation (less air to burn), have an e-fan, removed a lot of weight, and have tuned my PCM for MPG. I think your 19 MPG sounds good to me. I believe the EPA rates the I5 H3's at 18MPG. 🤓

[@ivan_germogenovich]

@@H3Humper, thank you! 😀

[@alexandergallegos5577]

@@H3Humper 22 mpg? Surre. Maybe of stock tires and going down hill. Realistic mixed driving os around 14 bro. Your weird. P.s more like at least a 4.to.5.hour job. 1 hour job. Yeah right. 😂

[@alexandergallegos5577]

Lol. You dont include all the stuff.you gotta remove to get to it. Including the battery and like ten different connectors. What about the fan shroud also? Your vid is sarcastic. Lol. Wish it only took in hour. This is an all day 1400 dollar job at dealer.

[@H3Humper]

Have you attempted the repair yourself? It sure did not take me all day to do and only cost me $50 in parts, though I am very comfortable and familiar with my engine bay. You seem pretty negative in your comments, and it is not very helpful. Different people have different abilities. I speak for myself and my own abilities, and hopefully encourage others to feel confident in their abilities, as well. If you feel the need to have someone else do your work at a dealership, I really do not understand why you're watching my videos in the first place. I create these videos to help people figure out their own problems and how a person can fix them. I don't create them for people to leave discouraging comments.

[@alexandergallegos5577]

@@H3Humper im not being negative. Im being a bit tenacious. Lol. I did it myself. Through engine bay from the top. Had to remove fan shrowd, alternator and battery w/box. Ive had the truck sine new. (2007) ive done all maintenance myself. Plugs. Oil changes, brakes etc. Im comfortable with her. Lol. I was watching your vid to see if anyone else had some.secret tips before sticking my fat fingers on the side between brake module and intake to get the 7th bolt. Lol. Also. Im getting im getting 14 combined with 33 kellys . What tunes/programmer are you using?

[@alexandergallegos5577]

Also. I do my mpg manually after i fill up and divide miles by fuel consumed. And overall it took me 5.5 hours. Close to 6 to cross my Ts and dot my i's. Lol

[@H3Humper]

@Alexander Gallegos alrighty 😎 I was taking your words in a different way. The previous owner of my H3 had failed to reattach the jiggly bits (wiring harnesses and bracket) below the intake manifold, which I didn't know existed until looking at a diagram (which is why I didn't include it in the video) and mine also doesn't have a battery box. I don't have a fan shrowd because I converted mine to a taurus e-fan. Having your H3 since new is awesome, and I bet it's nice knowing you're the only one to have worked on it. I tuned mine myself using HPtuners, which took some figuring out. I filmed a bunch of tuning videos but haven't made time to edit them yet. Learning how to tune was really helpful in developing my understanding of how the engine components and PCM work together with efficiency and power.