Outer Limits 4x4 Board

I have a 79 series with the petrol 1FZ-FE 4.5L I6 that has a TRD supercharger (approx 5-6 psi boost)

It is running a MoTeC ecu, and the guy that tuned it for my reckons that bigger injectors would be good as I am getting high up in the duty cycle at full load and full boost.

He said that maybe Nissan Patrol 4.8L VTC injectors might be the go, but there are about $150 each. I don't really want to drop a grand and find out they are not what I need.

Has anyone here had any experience with this. Have tried search but to no avail.

Cheers,

Mick

Yep when I was playing with my supercharger cruiser 4.5. The guy who was doing said that there are only 1 set of injectors that where bigger (that he knows of) the injectors are already pretty big hey. I seriously doubt bigger will help. Solong as your fuel pump is big enough with a good pressure regulator.

ps. Post some dyno sheets

you can install extra injector into intake manfold you then can run up to 12 psi with turbo 1fzfe or try rotary injectors they go huge in after market

They wont be anywhere near the top end of the large injector scale, toyota would have allowed for them to run at 75% or more duty cycle, without forcing above atmospheric air in,

Remembering atmosphere is roughly 14psi, hence vaccum on idle, so even 7psi above atmo is alot more fuel, plus the a/f ratio of a forced induction motor requires more fuel to be on the safe side, n/a motor 14.5:1, boosted 12.5:1 or lower when they are on boost.

You can buy injectors up to and beyond 1600cc, (indy blue big rotary injectors as was said. Most people with 1fz's run a 7th injector, or run 2 sets of injectors, but 2 sets are way over kill for a low boost application.

Have a look around toymods, there is a few serious 1fz's read the buildups.

What duty cycle are they running at, at full noise and full boost. Any higher than 90% i would change them, and they "should be changed at even less %.

If you are in dubai, they are king of the modified 1fz, most forged and aftermarket parts come form there, You can buy brand new injectors for around the $100 mark, you get what you pay for though, ussually the more expensive the injector the better the spray pattern = better low cycle control, better economy etc etc.

Are they top feed or side feed, 10mm or 14mm?, i purchased 4 750cc injectors a little while ago for $400 shipped, and you shouldnt need any bigger than those.

TheBigBoy wrote:ps. Post some dyno sheets

got to finish the exhuast first (3" straight through with side pipe exit), and then fit the intercooler. I ran it before without the intercooler, but it was just making too much heat.

tiny80 wrote:you can install extra injector into intake manfold you then can run up to 12 psi with turbo 1fzfe or try rotary injectors they go huge in after market

i had read somewhere on the internet that madza rx-7 series IV ones would be ok. I think they might be the low impedance type, whereas mine are high impedance.

I am going to check with the tuning guy once i get the mechanical work done.

Not sure what the duty cycle is, he just mentioned it was on the higher side. I have seen 80% DC mentioned as a 'safe' limit.

I had thought about adding injectors, but was worried about getting it in the right place so the fuel is properly atomising and not just dribbling down the manifold wall into #3 cylinder

I also forgot to mention I have seen that the standard injectors are 300cc, so I think an upgrade to 440cc would be fine.

rx7 injectors are 550cc, which would be fine, low or hi impedance doesn't matter if your running an aftermarket ecu, settings can be changed, top feed/side feed and size is the important decision.

If its pre 95 air flow meter set up type, it will need extra injectors x 2, and a microswitch, or new ones.

If it needs new ones, speak with aznew injectors in Dandenong Vic.

If its 95 on, they work great, add a Bosch 040 in the tank, and a rising rate fuel reg when it sees boost, and you wont see maximum duty cycle on them with up to 10 psi and a couple of hundered rw kw.

top feed high impedance 440cc injectors are a dime a dozen, late 80s-early 90s factory RX7 are the 550cc, 7MGE (JZA70) supra are 315. 1G Ecplise are 390cc, Skyline (the right model are 440cc STOCK)

So the stock 1FZ injectors, are they top feed high impedance 300cc??

Assassin_Offroad wrote:If its pre 95 air flow meter set up type, it will need extra injectors x 2, and a microswitch, or new ones.

If it needs new ones, speak with aznew injectors in Dandenong Vic.

If its 95 on, they work great, add a Bosch 040 in the tank, and a rising rate fuel reg when it sees boost, and you wont see maximum duty cycle on them with up to 10 psi and a couple of hundered rw kw.

Any 79 series is after OCT 99 so they all have the coilpacks etc same as the 1fz-fe in the 105 series

From another server, these are just stock rotor stuff, can get 750's 650's what ever basically, like was mentioned up to 1600 indy blues and may be more that are higher out there.

rotary top feed injector numbers -

year....motor/ car ...apspiration...ohms...plug-type...notch...size.. colour...number
83- 87 12A T low square centre 660 cc dark blue 195500-0610
83-87 13B HB Cosmo NT low square centre 690 cc green / blue 195500-0830.
84-85 13B GSL-SE NT low square center 700 cc orange 195500-0900
86-87 13B NT low square center 460cc red 195500-1350
86-87 13B T low square center 550cc tan 195500-1370
88 13B NT high square offset 460cc purple 195500-1350
88 13B T high square offset 550cc purple 195500-1370
89-91 13B NT high oval center 460cc red 195500-2010
89-91 13B T high oval center 550cc purple 195500-2020

dont confuse purple ones that have faded to a different colour
- very easy to confuse purple and tan when old, and also later pink purple ones fade to red
check the number on the side, cant go wrong

Hope it helps on the search
Cheers
Chello

If you post up the feed type (top/side) resistance across the injector (high/low) and the top o-ring, usually 10/14mm I beleive...

Then we can tell you what to get injectors from. I have a feeling that the 1UZ injectors fit this motor.. BUT I think the standard ones are between 200-251cc depending on where the motor is from.

GO79 wrote:

Assassin_Offroad wrote:If its pre 95 air flow meter set up type, it will need extra injectors x 2, and a microswitch, or new ones.

If it needs new ones, speak with aznew injectors in Dandenong Vic.

If its 95 on, they work great, add a Bosch 040 in the tank, and a rising rate fuel reg when it sees boost, and you wont see maximum duty cycle on them with up to 10 psi and a couple of hundered rw kw.

Any 79 series is after OCT 99 so they all have the coilpacks etc same as the 1fz-fe in the 105 series

Then it shouldnt need injectors, but fuel pump and reg.

Assassin_Offroad wrote:If its pre 95 air flow meter set up type, it will need extra injectors x 2, and a microswitch, or new ones.

If it needs new ones, speak with aznew injectors in Dandenong Vic.

If its 95 on, they work great, add a Bosch 040 in the tank, and a rising rate fuel reg when it sees boost, and you wont see maximum duty cycle on them with up to 10 psi and a couple of hundered rw kw.

do you know what type of injectors they run?

Can you please explain about the rising rate fuel reg, so it increases pressure to the injectors, thereby increasing flow at higher revs? Or just increasing flow at what point, how does the rising rate work?

The rising rate regulator increases fuel pressure available to injecter so its duty cycle can be reduced. The std one is not good enough....make sure you get a good pump,

The reg has boost pressure, so it lifts fuel pressure by up to 30 psi at boost, less for less boost, and is adjustable.

We normally mount them with gauge so you can see what you have while adjusting it.

The Bosch 040 pump is an easy mount for the toyota sender set up, but make sure you keep it rubber mounted as it can be a little noisy.

This will help keep up fuel flow while making boost, as the standard Toyota pump wont if making the power it should.

how do the suoer charged 1fz's in power and tourae and driverbility compared to the turbod 1fz's

OK... so it adjusts fuel pressure according to manifold pressure. The standard one won't do, or just won't handle the boost.

Std one is designed to sense vacuum and lower fuel pressure, or no vacuum and raise it (wide open throttle) but it doesnt increase much at all when boost is added, the rising rate is said to be a ratio of 1-1.5, so each psi boost it senses, it adds 1.5 fuel pressure. Its also worth noting that all 80 series run thesame injecter, 16 ohm from memory, but the flow meter early ones cant sense the extra volume of air, so the computer is tricked to adjust by overfueling and oxygen sensor then backs off duty cycle....later fzfe has air mass meter and has no problem sensing extra flow. Again, from memory, the 1fzfe injecter (pink) is around the 300cc mark, 7mgte (black) is 440 but plugs ontop are different,,,,the std supra 7m has a yellow injecter and is 350cc but again,a different plug.
Andrew