4-Hole Fuel Injectors?

[TS888]

There's no magic here. The guy is selling Bosch injectors with similar impedance and flow rate to the OEM Denso injectors, with adapter pigtails for the wires.

Fuel injectors are widely interchangeable. I swapped the original injectors in my BMW motorcycle for a set from an Audi car engine. They were cheaper and were the newer 4 hole style vs. single pintle.

 

[Spook50]

There's no magic here. The guy is selling Bosch injectors with similar impedance and flow rate to the OEM Denso injectors, with adapter pigtails for the wires.

Fuel injectors are widely interchangeable. I swapped the original injectors in my BMW motorcycle for a set from an Audi car engine. They were cheaper and were the newer 4 hole style vs. single pintle.

So did you see any benefits when running them in your bike?

 

[TS888]

So did you see any benefits when running them in your bike?

I'd hesitate to claim any improvement purely from the injectors. I went through the intake and fuel system from tank to cylinder head, so it's been cleaned, all the old dry rubber replaced, new fuel lines, the TB's balanced, throttle cable adjusted and lubed, the TPS set to spec... It runs much better. All I would say is there was no downside to the newer injectors. The bike started up first try, idles perfect, there are no flat spots and throttle response is crisp.

 

[cruisermatt]

Just ordered the set from eBay. Will report back in a few days when package arrives, then again on performance.

Well guys,
With the help of a friend, I installed these injectors today. On initial start up, the 3FE seems to idle smoother. These injectors are louder. The entire rpm range seems smoother. Install went well, the same as installing the standard injectors. I have about 15 miles on them so far. I'll report back with performance and mileage later with more miles.

You installed the Bosch modified injectors or the FJ80 injectors? Either way a longer-term report would be appreciated

 

[IBFJ62]

Just for those that might be thinking it, I recently replaced my injectors during the engine rebuild, and I sent mine out to be remanufactured. I spoke with the guy doing it about replacing the pintels with the 4 hole style, and after checking his specs, couldn't find any that would work with the original injectors. I opted to go with the original single pintel style, after recently helping a friend with a rebuild ('95 4-Runner) and he had a set of the 'not original - with a pigtail conversion', which didn't even come close to fitting in the fuel rails. I can't say just how much difference fresh injectors made, as it was on a fresh engine and I gasket matched the intake, but it was very noticeably smoother and more powerful pull through the gears. Freeway speed with an H55F, there's plenty of passing power in 5th. Worth doing if you've got some mileage on the old injectors. YMMV.

 

[cruisermatt]

We'll see. After next week I'll have 12 spare OEM injectors to play with among other things, so it will be fun experiment time.

The original engine I'm pulling out will become a big experiment I think, knife edge crank 3FE anyone? Backwoods Turbo? Not sure yet...

 

[cruisermatt]

If anything, buying these is a good idea because they're the same price as rebuilding the originals and it took them three days to get to Florida from California. Ordered Monday night, got them Thursday morning.

The packaging was superb.

Here are the wire harness adapters

Now this is where I got worried, the difference in size of the injector body threw me off.

However a quick mock-up in the fuel rail shows that this won't be an issue.

And make sure to clean your lower intake manifold out!

 

[cruisermatt]

All clean.

and here is a close up of the injector spray pattern

I'll have a report on how it runs in a few days.

 

[IBFJ62]

Just make sure you get a good tight fit, top and bottom, and that the injector itself seats deeply enough. That was the issue we had with my buddies 4 runner, the diameter of the new injectors just wasn't enough to make the fit pressure tight. Interested to hear the updates, keep em coming.

 

[Spook50]

I'm very curious to see what kind of differences you notice running these. I've been planning to have a set of injectors cleaned for a long time and still haven't gotten around to it.

BTW how difficult was it to get to them overall? Did you have to remove the lower intake manifold? Curious if I'd have to order a new intake/exhaust manifold gasket once I eventually do something with my injectors.

 

[cruisermatt]

I'm installing them on my rebuilt motor that I'm swapping this weekend, still haven't ran it yet but it's 1mm overbore and decked a little bit so many "differences", going to be hard to determine how much the injectors effect the running. Like I said, I only bought them for the quickness if delivery, if they help how the engine runs then that's just a bonus.

As for involvement of installation, I would highly recommended removing the lower intake manifold because the manifold in the pictures above had 175K on it. It had a lot of build-up of grossness, and yours has 90K more miles of build up. I sandblasted it earlier but at the time didn't realize the plastic "cups" were removable, so I pulled them out. They have an o-ring on each on, and were gross, and they had junk under them. cleaned up nicely with a dremel tool with brass brush attachment, but sand blasting would work well too. So yeah you wanna oull it so you don't get junk in your engine. The o-rings (about 14mm in diameter) came with the engine gasket kit, so if you're planning on pulling your cylinder head for a rebuild this would be a good time to do the injectors as well.

 

[Stumpalama]

I'm installing them on my rebuilt motor that I'm swapping this weekend, still haven't ran it yet but it's 1mm overbore and decked a little bit so many "differences", going to be hard to determine how much the injectors effect the running. Like I said, I only bought them for the quickness if delivery, if they help how the engine runs then that's just a bonus.

As for involvement of installation, I would highly recommended removing the lower intake manifold because the manifold in the pictures above had 175K on it. It had a lot of build-up of grossness, and yours has 90K more miles of build up. I sandblasted it earlier but at the time didn't realize the plastic "cups" were removable, so I pulled them out. They have an o-ring on each on, and were gross, and they had junk under them. cleaned up nicely with a dremel tool with brass brush attachment, but sand blasting would work well too. So yeah you wanna oull it so you don't get junk in your engine. The o-rings (about 14mm in diameter) came with the engine gasket kit, so if you're planning on pulling your cylinder head for a rebuild this would be a good time to do the injectors as well.

Interested to hear how this goes...

 

[Kleatus]

I'm running a set of the same injectors. My old ones presumably had 368k on them, so I'm not sure I can offer any opinion on performance other than that these Bosch ones do indeed work. As noted before they are definitely louder. I cannot recommend them however (at least not as a plug and play option) because the wiring pigtails they send force you to contort the original harness to the point of cracking insulation, and keeping an eye on all the pigtails while reassembling the manifold is a chore, especially around the EGR tube heat shield. If someone has their mind set on running these, I would highly recommend pulling the injector harness apart and splicing in the new connectors from the pigtails to the original harness. And be sure to get new OEM cups to go in the manifold.

 

[cruisermatt]

Don't have EGR so that might make this a bit easier, and my cups cleaned up nicely. I'll be installing them on my engine (on a stand in the garage) so take that for what it's worth but I might have an easier experience.

 

[cruisermatt]

I didn't splice the connections (I kept the adapters whole and wrapped each connection in tape) and as long as you're de-smogged they fit fine.

 

[cruisermatt]

These are definitely louder! I'm glad I didn't solve the connections because I ended up switching a few of them between the cylinders.

 

[Stumpalama]

So louder, but how loud, like I can hear them with the hood shut and sitting in the driver's seat annoying?

 

[cruisermatt]

So louder, but how loud, like I can hear them with the hood shut and sitting in the driver's seat annoying?

Not that bad, loud enough if you are listening for them though. I have my valves set 0.05" loose for break-in purposes so that might be part of the volume. You wouldn't hear it with the hood closed.

 

[cruisermatt]

They are all getting power (they are all clicking audibly). However 2 and 5 are running SUPER rich. Going to borescope with the intake off and see what's going on but I think I've got two bad injectors.

 

[cruisermatt]

Just pulled them all out, putting the OEM ones back in. I want my rig to run right and Oside Tiger is going to get an earful.

Guess I have to pull this sticker off