LS Basics, Injector Flow

[@SuperEastcoast]

Your videos are awesome and appreciated. I really like the no bullshit just being real you project. Keep it coming.

[@AgiDaKinG]

When I was doing my truck build a few years ago it was before anyone was decapping and testing the truck injectors, so when I went to the dyno I had the Deka 80s installed and I never got my stock truck injectors back and I really didnt think twice about it but now I wish I had gotten them back lol

[@TheDrivewayEngineer]

Lessons learned lol.

[@stevie..d..pontiactransamm1215]

Interesting flow numbers by that chart my man👍.

[@rememberussliberty1822]

I have a set of 12613412 in my LQ9. They come on the 2010 (?) flex fuel trucks and are 50lb @ 58psi. Got them brand new on ebay for $70 from a company that does CNG conversions on fleet trucks, they do require adapters though.

[@TheDrivewayEngineer]

That's a good price!

[@elprostipirugolfo8176]

How is it running with those injectors on your lq9... I’m building my lq9 with a tick performance sns stage 2 cam and 243heads just looking what would be the best injectors for it

[@elprostipirugolfo8176]

How is it running with those injectors on your lq9... I’m building my lq9 with a tick performance sns stage 2 cam and 243heads just looking what would be the best injectors for it

[@sock979]

I'm too lazy to check if it's already been said and I know this is an old post but flow rates are by a certain pressure like usually stock flow rates from the OEM or at 43.5 lb per hour which is what most of the 90s cars use a lot of these newer cars that aren't running return fuel systems are running like 60 pounds of fuel pressure so that 33 lb an hour flex fuel is actually like a 37 so don't just look at the flow rate you have to look at the flow rate at a certain pressure rating also injectors have different lengths if you put an injector on your car and it's not the same size as the old one a lot of times you have to get spacers to raise the fuel rails also I believe some might even have a slightly different diameter so you do need to do your research if you're going to try and use injectors from a different car. Also there's different wiring connectors dv1 ev6 ev12 the old early fat Bosch jetronic I think it's called so you got to be careful of that as well also one thing I haven't heard people cover he kind of went over it with decapping if you're going to use a four-valve engine injector on a two valve the spray pattern is different and you might get more spray on the intake Port walls then if you use one from a two valve injector because the whole intake Port shape is wider that is only known to me from reading I have no data on it so take that with a grain of salt until you can get someone to actually test that.

[@markscott8433]

Good info, thanks for taking the time

[@TheDrivewayEngineer]

Thanks for watching!

[@fasnuf]

so how does this decap change the atomization of the fuel and how it performs before the burn? thanks

[@hydrocarbon82]

For Delphi/GM they become a very narrow beam with poor atomization. It's very similar to the Siemens Deka 4's, which you can google. Not a big deal for WOT runs, but can lead to issues at low loads.

[@crischalmers1277]

My 2015 Malibu 2.5L LKW motor has 99 lb/hr injector's. Wonder what they are decapped.

[@calebhurteau4230]

Thx for making these vids. They are really helpful and answer alot of my ?..

[@ginjaman4784]

Will the GM 3.1/3.4/3.8 injectors work with a 5.3? I'd figure if anything you might have to change the pigtail design if it's different. Was gonna take you advice and get a bunch of v6 injectors and decap them. Planning on running a boosted 5.3. Thank you.

[@LSCHEVYRYDER254]

great info

[@james10739]

My 03 suburban has a regular black gas cap I think it is the factory cap but it says flex fuel inside the gas door

[@deankay4434]

James Holdbrook The 8th digit will say “Z” which means flex fuel. Not all got a yellow gas cap as a novelty to thing of corn. They also had an in-line fuel sensor that detected the less dense ethanol and the temperature as well. A $350 part mounted on the frame before the fuel filter. This second design for many but third design for others as they used a PCM refueling strategy after 2 gallons was added. The problem was, the vehicle had to reach normal coolant temps at road speed while ignoring fuel trim for re-setting to new mixture. ASE Master Tech Retired

[@cedricdeoan1214]

I need some help from the driveway engineer I recently did a ls swap from start to finish everything new all new sensors. My car cranks but won’t start, it only starts if I spray starter fluid in the throttle body. I checked the hot wires at the injectors and they were getting fire. And I checked for fuel pressure and it’s like 58 psi. What do you think could be the problem

[@TheDrivewayEngineer]

You've already solved your problem, your injectors are not firing. LS engines switch grounds, not hots, to fire injectors

[@cedricdeoan1214]

So how do I fix this problem

[@TheDrivewayEngineer]

@@cedricdeoan1214 I have no idea from across the internet, you're going to have to do more diagnostics.. Typically it's a ground issue though

[@cedricdeoan1214]

Thanks I watch your videos all the time. I’m very thankful that you responded so quickly. You really know these ls engines

[@TheDrivewayEngineer]

@@cedricdeoan1214 good luck man!

[@jamesgadd931]

Dose this work on the street or not?

[@TheDrivewayEngineer]

No

[@antonisautos8704]

Can I use the 6.2 flex injectors part number 12609749 in place of the stock L59 injectors out of an 02 Yukon?

[@TheDrivewayEngineer]

You can use any injectors you want as long as you know the flow numbers

[@antonisautos8704]

So I'd have to k ow the flow rate during the tuning process so that way it runs right? Just wanna make sure I got everything squared away. Like knowing if the connector is the same and if they're the same length and have the same diameter where it goes into the manifold and fuel rail ect.

[@protector326]

Dumb question but how do you tell the cubic inches on your ls when the car has a replacement engine.

[@turkeyboyjh1]

Head numbers are a good hint only for sure way to tell 5.3/4.8 is pull a head and measure bore

[@earlbrown]

@@turkeyboyjh1 5.3 and 4.8 have the same bore as they share the same block. But you can pop out a plug and look at the pistons with a boreoscope. 4.8's are flat tops and 5.3's are dished (most of the time)

[@sxs4l245]

So.....basically you 350 to 500 horse power na guys should get "truck" (pickup) flex fuel injectors? Thats my take away. Thanks JR.

[@TheDrivewayEngineer]

Anything over 28Lbs will do for most people

[@calebhurteau4230]

Hi. I wanting to know if u drilled out the restricer plate holes on the injector and made them bigger instead of decapping them would that work that way they would still seal correct..is that possible to do??thx

[@TheDrivewayEngineer]

They generally seal correctly decapped. I'm not sure how you would drill the holes larger, and not get into the pintle. Or how much of an effect it would even have, by the time you drilled them large enough to get into the 70 lb/hr range, they'd basically be decapped lol.

[@youngestson6537]

Great information.

[@deankay4434]

This is the directional spray plate to create better atomization of fuel, not a restrictor plate. But also not my injectors. This can allow hot soak to turn volatiles and other light aromatics in the fuel to cook onto the pintle of the injector, sticking it or creating a spray dam directing fuel to different directions. But, if you want to do this, go ahead. It’s not my injectors. I’ve worked on multi port electric fuel injected vehicles since 1976. There are always ways to pound for ponies. Not saying right or wrong, just without additional comments.

[@matthewstansbury3047]

By grinding off the orifice plate you ruin your static controlled flow rate for the injectors as a unit and the spray pattern. Like taking the nozzle off a garden hose. I have never done this or been in a car that has it done so I’m just going off hearsay but doesn’t the spray pattern effect cold starting and driveability?? I would think the most difficult thing would be tuning it? What are you experiences with drivability and the fueling tables in the tune? Or is this a max effort 1/4 mile only kind of thing?

[@TheDrivewayEngineer]

As far as tuning goes you just up the actually flow rate to whatever you get from flowing. SO if they go to 70 lbs, that's what you set. Hold time and everything else stay the same. If the spray pattern has a real world effect on cold starting or driveability, I'm not seeing it in my own truck. It cold started and idled fine. Now, it's not something that anyone N/A needs to do, but if your goal is modest, 5-600hp, then you can get there for the cost of injectors and flowing them. I did have two in my batch that flowed at right angles afterward that went in the trash, you absolutely cannot decapp 8, and jam them in your engine.

[@matthewstansbury3047]

I was just wondering because I know with 42# injectors that were flow matched etc I still needed to touch into the transient fueling or it would load up very bad on decel and the stfts couldn’t react quick enough when back on the throttle and it would stumble for a second under light throttle. Had something to do with my min pulse width wouldn’t drop low enough if I remember which was causing an overly rich mixture that the cam overlap puked right into my O2s. I’d figure these would have the same issue? But I have cncd heads and there’s a lot of tables involving the fuel impact on walls and boiling rate etc. that I don’t comprehend as well as I’d like so my issues may have been to the redesigned heads.

[@Crysmatic]

hack job. those "restrictors" atomize fuel so it burns quickly and completely. decapping is a good way to wash down your cylinder walls with raw fuel, and cover your insides with soot. you can find 80 lb/hr injectors with proper atomization for $50 each. why don't you provide flow tables so people have a fighting chance of tuning. btw, Bosch is rhymes with wash.

[@TheDrivewayEngineer]

I really appreciate you watching and commenting on all my videos 😂