Need injectors, any suggestions?

[grandpa_spec98]

The other day I was driving around, everything was normal, car had decent power and was running great. Sometime later that day I noticed the smell of gasoline and a slight hesitation under acceleration. Great. One morning letting the car warm up, I notice the smell again, plus after leaving the driveway saw a fairly large puddle of fluid. Knowing the car wasn’t leaking before I quickly check to see what it is. Instantly knew it was gasoline, look back at the car and I saw it dripping at an almost impossible rate. Today when I went to check what the problem was, I pulled the left bank fuel rail and as I pulled out the last 3 injectors, the plastic bottom was cracked off and the o-rings were crunchy and mangled. Great again. (Probably original, 280k mile injectors) This car is my only transportation and I don’t really want to spend the $60 an injector for OE replacements, does anyone have any suggestions for until I can switch back to some OE Denso injectors?

[Sunshine Guy]

Try going to RockAuto.com and see what fuel injector choices they offer for your specific year and model.  Prices will be far below dealer and they might even have Denso brand as an option.

[RX400h]

I agree with Florida guy, Stephen. Rockauto.com has some very good prices.

[grandpa_spec98]

I did look there, there appears to be some injectors that should work until I can put some OE Denso injectors in.

[paulo57509]

If you're replacing the four rear injectors (5-7 and 6-8) be sure to swap over the foam insulators and plastic retainers to the replacement injectors.

[grandpa_spec98]

Now that you mentioned this, is it possible to replace just the left bank of injectors? I noticed that the right bank of injectors are aftermarket, and the seals look almost new and the left bank were Denso injectors with cracked faded seals, I am guessing replacing the left bank would even out some of the rough running problems if I end up with Rock injectors that match the right bank. Just checking before I decide to go ahead and it runs on 6 1/2 cylinders.

[paulo57509]

You can replace the injectors individually.  The only difficult thing is getting the fuel line out of the way; there's a bolt that in the back of the manifold that might be hard to get to (I did it with the manifold removed).

There are special seal washers used at the pulsation dampers that you can only get from Toyota.

[grandpa_spec98]

Checking back on this now that my parts are in and I’m going to take on the job, how could that bolt come off with the intake manifold still on the engine, can a socket set/wrench fit back there? I’d guess it’d be best to go out there and check but I’d like confirmation before I try.

[paulo57509]

It's a PITA to get to the rear of the intake manifold to take out that bolt.  The engine shown below is a JDM engine so the main harness is routed to the passenger side.

You can unbolt the plastic harness housing from the coolant crossover but it's not going to get out of the way.

You might be able to separate the plenum from the lower manifold; if you remove the ACIS actuator diaphragm it may give you enough room.  I don't know if you can just bend the fuel line out of the way.  The tubing may fracture.

[Jeremy M.]

I was able to (very uncomfortably) squeeze a hand with a wrench for the back bolt to remove it in the past; if you've got an assistant with smaller hands, they're the best candidate. I actually was never able to get the bracket lined back up assembling it though; I ended up taking the intake manifold off to swing somewhat sideways and reach the bolt.

[300EChuck]

My company is Fuel Injector Specialists, located in Colorado.

I own a 1990 LS400, and I"m not here trolling for injector business, but my advice (and experience) on these cars is this:

The chance of you having 8 good injectors is just about nil.  I've rebuilt plenty of these, and about 10 percent are not buildable -- the spray pattern goes sideways or they leak down.  Denso from the factory.  The quality of Bosch?  Nope, but if you keep water out of the gas, the majority of the factory injectors will last forever, it's just that Bosch uses a higher quality rust resistant super hard stainless metal alloy.  Bosch will not substitute for Denso, in this case.  Alas.

Rough Idle?  One or two bad injectors.  Same with hard start.  Same with burned up catalytic convertors -- these cats will outlive the car, if they have the correct fuel ratio ahead of them.  Pintle caps and seals and filters?  All replaceable.  Good injectors and these engines will purr.

Factory shop manual (of which I just paid $350 for the complete paper set) infers that it is possible to pull these injectors with the intake on.  Nonsense.  Think ahead and buy the throttle body and upper plenum gasket from Rock Auto.  You'll need both.  As another hint, the bottom bolts on the throttle body are impossible to start without a flexible magnetic/grab hook retrieval tool.  Invaluable.  NAPA, $20.  Best money you will ever spend.  Eliminates many bad words.  Put the head of the bolt on the tool, using only the magnetic function not the grab hook, then bend yourself way down to see the opening in the throttle body, insert the bolt, then slide the tool off at a 90 degree angle.  Voila.  You don't use this tool, and the bolt will drop into the valley.  Ouch.

Intake plenum off, but first, careful careful with all those hoses, and be even more careful with the hoses at the front EGR temp sensor, the one that has two plastic barbed outlets and screws in vertically into the cooling passage. Aw, forget it. These outlets all break.  You will break yours.  Remove the sensor (unobtainable now, and was $300 plus dollars anyway.  What the?), go to Napa and buy some small plastic barbed tees, cut them to match the ones you broke off.  If you can pull your broken originals out of the hoses, even better.  Then, take some super glue, a powerful magnifier so you can see to match the broken edges up perfectly, and judiciously super glue the broken tee back onto the temp sensor.  That means don't use so much super glue that you block the ports.  You will check with a small drill bit when you are all finished anyway.  That super glue's only function is to get the tee to stay on from whence it (they) departed.  Not strong enough to be anything but a placement.  Next, buy some J&B plastic mender epoxy.  Squeeze out a small amount of this stuff from its double syringe, on a cardboard piece, and stir while counting slowly to 30.  Daub this mixture onto the tee/sensor broken area, which you cleaned of course, covering all sides nicely, leaving the barb exposed.  Set the sensor aside ( as mentioned, you pulled this sensor from the engine, right?  15/16 combo wrench. And drained the radiator to even make this possible?  This only makes sense.  Ahem. )

Set this sensor aside for 24 hours.  In a warm room.  Don't be tempted to readjust the tee outlets even slightly.  That''s what the super glue was for.  If you do, the epoxy strength will absolutely disappear.  A day later this fitting will be bulletproof.  Never seen an older LS where these aren't busted off.  This sensor stops the EGR from working when the engine is cold, and lets vacuum pass when it's warm.  Your engine needs this. The earth's atmosphere needs this.  All of humanity needs this.  You get the idea.

Pull the intake.  Put all those bolts in a container.  They re-torque at 20 lbs or so.  Not much. You set them somewhere under hood and they will fall off, never to be seen again.  Passing children will learn new words.  Now, you can easily reach the fuel rails. The supply line to the pressure regulator and the line itself has banjo bolts.  Nice design, but each banjo bolt has a copper washer on top and bottom.  Take a very deep breath, put on your glasses, and DON'T lose those copper washers.  Factory shop manual insists you need to replace them.  Not necessary.  Available at NAPA if you do.

The fuel rail holds the injectors in.  The hardest part of injector service is removing the wiring clips from the injectors.  The little tab pushes down, and the clip pulls off.  Don't rush this step.  Don't yank without being sure the clip is released.  Push down, then pull up.  If you successfully get all the clips off without breaking some you qualify for a trophy of some type.  Perhaps an old bowling trophy, or a second place spelling ribbon, etc.  Indeed, you are truly a master mechanic.

Buy quality new injectors if you can, but you can't.  Don't buy Ultra. Chinese garbage.  Not worth the effort to toss in the recycle bin.  Rock has rebuilds, but we kick back about 15% of them because they are defective, usually pattern problems.  Or they leak down.  Slow engine death.  Perfect injectors and this old girl purrs.  Oh yeah.  There is a cold start injector at the bottom of the intake plenum.  Unobtainable.  We can clean and build them.  If they're not rotted out.

We are junkyard doggies.  A proud thing.  When the occasional first gen LS400 comes into the wrecking yards, we grab extra injectors, computer, complete padded dash and glove box door if possible (very rare), all the missing top engine shrouds, a mass air flow sensor, throttle position sensors (plural), door lock motors if needed, etc.

Final note.  Don't think you can upgrade from the Pioneer radio to the Nakamichi.  Ain't like the Buick Riviera with Bose GOLD.  All the good stuff is in the radio, not due to additional active amps in the door units.  Nakamichi rear speaker is a monster, but needs its own amp in the back.  Meaning the wiring harness.  Meaning the wiring harness is completely different at the radio.  Oh well.  Life is too short.

And Interior?  Went with the Katzkin leather, $1000 plus.  We shall see.  Doesn't have that extra double pleat in the center, but we'll live with that. 

 

[RX400h]

Great advice, Chuck! It looks like you used to have a Mercedes 300?
I'll bet your Lexus was far more reliable. 😏

[paulo57509]

Only thing I can add is in regards to the removal of the intake manifold.

I've found that any 1UZ (engine still in the chassis) that has an intake manifold with the ACIS, the manifold needs to lifted straight off the engine in order for the vacuum reservoir, vacuum switch, etc. to be able to clear the front coolant crossover and the manifold mounting studs.

Because of the lack of clearance at the firewall, I have never been able to remove the manifold without removing the front coolant crossover first.

• Remove the manifold nuts and bolts.
• With your third hand, raise the front of the manifold to get wrench clearance to the crossover fasteners.
• Remove the crossover.
• Remove the manifold.
• Reassembly in reverse order.

[grandpa_spec98]

Seeking some info here, is there a specific way that the injectors go into the rail, a specific way they should be inserted into the port, and a torque spec for the two nuts that hold down the rail, having problems with injectors seating correctly.

[Jeremy M.]

Only specificity is to not be upside down or backwards lol- I did have trouble getting my injectors in without pinching/rolling tearing a couple o-rings, the remanned injectors had some crappy ones. 

If you're having trouble with one of the injectors springing a leak, I'd recommend OEM o-rings and liberal application of some gasoline-soluble lube.

If you're just having trouble getting all four lined up in the rail, I got mine in with good success by roughly lining them up in their holes, placing the rail (without the banjo bolts, if you can help it) over the four injectors (already in the manifold) and double checking that they're straight, then gently and evenly pushing the rail down.

Lube is your friend; every time you deal with an o-rings, lots of a high quality lube will help you along and save you from a trip to buy another o-ring. I have used Maxima brand assembly grease for applications like this, albeit less so than I would an oil, so the grease doesn't get in the injector immediately and clog it, and instead dissolves through gradually.

[grandpa_spec98]

Unfortunately it seems that this economy has yielded some bad conditions for my job, and I am now unemployed. My car is down and I have around $200 to replace either the left bank of injectors or all of the injectors as they are leaking again, if anyone has any suggestions for parts or any lists that would be great. 

[paulo57509]

On 5/1/2022 at 12:43 PM, grandpa_spec98 said:

Seeking some info here, is there a specific way that the injectors go into the rail, a specific way they should be inserted into the port, and a torque spec for the two nuts that hold down the rail, having problems with injectors seating correctly.

Sorry to hear about the employment situation.  This economy is effecting most everyone in bad ways.

For future reference, see attached.

 

SF-22 Injector - Removal.pdf SF-23 Injector - Inspection.pdf SF-25 Injector - Installation.pdf

[grandpa_spec98]

Got some new injectors, upon replacing and starting there was a loud knocking, which I thought to be rod knock but the sound subsided after a minute of idling, could there be knocking from incorrect fueling or water in the cylinders while the fuel rail was out? Video is attached.

 

 

 

[Jeremy M.]

As long as it's gone, I wouldn't worry about it too much- rod knock wouldn't disappear on you, but that could have been spark knock/detonation.

As for the why of it, I'm pretty stumped. Unless you had a fair amount of a very volatile liquid in your fuel rails (low octane fuel etc.) I can't see a reason for detonation.

[300EChuck]

With the intake off, and the fuel rails off and set aside, now you are ready to install the injectors.  Place the round square cut injector to intake gaskets into the intake FIRST.  Use some clean oil if necessary.  We use trans rebuilder seal lube, Red or green.

You will have good injector plastic pintle caps.  One assumes.  These fit perfectly into the round gaskets, maybe twisting a bit.  Then you can put the wires and clips back on to the injectors.  Pulling up slightly to make sure the clips are tight.  If, however, you broke a security clip on the clip itself, don't panic.  Just put a slight daub of Permatex ultra black silicone on the EXTERIOR of the clip, on the side, where it meets the injector.  At the base of the clip.  The clip will now stay on but won't vibrate loose.  No silicone anywhere near the electrical connection itself of course.  Pulling that injector in the future only means slicing a 1/4 inch long daub of silicone.  Easy Peazy.  Neat huh?

Now, with lube on the top o rings of the injectors, drop down the fuel rails.  Each rail has two bolts to secure it to the intake.  After the rails are secure, you can rotate each injector slightly, because they actually float a bit.  Voila!