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I'd really like to install bigger fuel injectors (from a vibe GT) and run without the fith injector on the s/c. My main question is if I need to reprogram the ecu or Unichip to run the larger injectors or if they will just flow more fuel.

Hey Lancer, you will need to have it reprogrammed to run the 4 main injectors at a higher duty cycle to take up the slack from not using the 5th injector. The 2ZZ injectors will flow at a slightly higher rate than the 1ZZ injectors with out doing anything, but not nearly enough to remove the 5th injector. Your Unichip is programmed to use the 5th injector for the extra fuel needed while running your S/C now. If you take that off and just run the 4 main injectors you will be running very lean and.....well...... then.......BOOM! Bye, bye engine. the Unichip will not automatically adjust your injector duty cycle for you. If you get the 2ZZ injectors, try to get the Brown ones from the Celica GT-S they flow at 380cc(max). The yellow and grey 2ZZ injectors flow around 330cc(max) or so. The stock 1ZZ injectors that you have now are only flowing at 260cc (max).

Thank's man. You pretty much summed up what I thought, but wasn't sure of. And those flow rates are just what I needed!With the 5th injector pluged in, the car runs VERY rich, bogs a lot, have TONS of black smoke pouring out the exhaust (very much like a turbo diesil!), and the power is noticably NOT linear at WOT. You feel it pull real hard then it levels out a tad, then starts to pull again, all the way up the rpm's. With the w/i turned on it's a little worse. When I unplug it, it runs only a little rich, and the power curve is much smoother and it feels a little stronger. So I was thinking to just up the main injectors a little just to make it safer. From what I keep reading over and over, the 5th injector is mostly used for controlling exhaust temps (in an attempt to preserve the cat. converter) by running the engine rich. I'd like to use bigger main injectors and use the 5th for water/meth injection. I really need a wideband and a dyno tune! And I need to check my plugs!

If you could get your Unichip dynotuned by a Unichip dealer, the gains would be significant. Running rich kills your power and as said, running lean goes boom.

If it were me, I would get the big injectors lose the 5th and get a custom tune. I think that any of the 2zz injectors would work but bigger sure wont hurt. I'd keep it as rich as possible without losing power under load to help keep thing cool and not burn up the CAT or cause even minor knock. There's a reason it's that rich but you can get a more consistant tune without the 5th injector and get it closer to right without worries. I'd also be mindful of keeping my injectors clean.

Thank's all for your input! Not worried about the cat. Burned that out last year. (Another casualty from running too rich ) Running this rich also 'washes' the cylinder walls which makes for greater wear on the piston rings.The dyno tune is the only thing I hate about the Unichip. Only a handful of shops do that in the US. And none of them are in WI. Cleaning the injectors was the first thing I did to trouble shoot my ultra rich problem. Already sent the unichip back twice this year to have them tune it down, but like you said, I need a dyno tune.Been running without the 5th injector for about 2 weeks now. I just pluged it in today for a 2 hour trip to my grandparents for deer hunting. Ran like crap everytime I came off the highway and even died pulling up to a red light. Then puttered and almost stalled when I drove off from another light. Unpluged it on the way home and it ran realy nice. So I'm gonna go with the larger injectors and stop using the 5th. Can you pick them up at an auto parts store or is it a 'Dealership Only' part?

Try looking for a deal on NewCelica or MO as well.Yeah, I thing the closest Unichip tuner for you is In NaperVille, IL a Chicago Suburb.

Here is a set from NewCelica.org for $225 shipped: http://www.newcelica.org/forum...16783

Quote, originally posted by BlueCrush »Here is a set from NewCelica.org for $225 shipped: http://www.newcelica.org/forum...16783those look like a good size for Lancer's car. If you get 2zz injectors, don't you have to do something to them to make them fit?Lancer, do your stock injectors stay rich at the lower rev's w/o the filth injector?With my turbo, a real crucial area of not detonating in the tune is right at the onset of boost, which for me is around 3k rpms. Wot is not as big as an issue for me, but my fuel set up is very unconventional. I guess I am wondering if the unichip takes you out of closed loop when you start boosting, or does that still only happen when you get closer to wot??I am still using an rrfpr and stock injectors, and I think that it is great because everything is stock until boost. The only thing is, that I dont know if there would be extra stress on the fuel rail in a SC car with my fuel set up because I dont know if you are in boost more than me. ??It seems to me, that at 10psi of boost , you are effectively loosing 10psi of fuel pressure , which means loss of fuel at wot in the stock set up. Just raising the fp 10 psi at at 10 psi of boost will keep your fp at a stock rate. What I do is raise the fp to around 100psi at wot, and 10psi of boost......and I havent had an injector fail in the last four years.

Quote, originally posted by Lancer »I'd really like to install bigger fuel injectors (from a vibe GT) and run without the fith injector on the s/c. My main question is if I need to reprogram the ecu or Unichip to run the larger injectors or if they will just flow more fuel.I seem to remember someone on spyderchat that put 2zz injectors in their turbo 1zz spyder and ran it that way for a while .(I think it was the the user with Hawaii in his name)He just ran them with the stock ecu. Sometimes there are issues with idle and larger injectors though.As a side note, The very 1st turbo kit for the 1zz spyder, the Top secret kit from Japan , ran 4.5psi on stock injectors and no piggyback for the fuel. It did have a replacement fpr in the fuel tank though. It raised the FP to about 60psi constant, something like that. The charge air was not intercooledAlso, The 1st Turbo Performance turbo kit for the 1zz celica ran 5psi with no engine management and stock injectors, but it did have an intercooler.boost came on after 3k. You might want to talk to Matt at MWR , he knows the history of all these kits and has been dealing with the 1zz longer than anyone. He is the guy to talk to...he might have the injectors you are looking for any way.

If you are planning on a highy modded NA 1zz would larger injectors be beneficial? and do they just bolt right on in place of the stock units? i am planning on about every bolt-on known to man and maybe even some internal head work and probably be using the Unichip. any opinions on this?

Quote, originally posted by Faultline »Lancer, do your stock injectors stay rich at the lower rev's w/o the filth injector? I guess I am wondering if the unichip takes you out of closed loop when you start boosting, or does that still only happen when you get closer to wot??My a/f ratio runs a little lean, mostly stioch when not in boost. Just like it always did. As it nears WOT, it switches to open loop and goes rich. As the boost goes up (like when I let the rpms go up without shifting), it gets only a littler richer (just in stioc to rich area) until it switches to open loop at about 7psi of boost. Then it stays solidly in the rich area. This is all with out the 5th injector.Quote, originally posted by Faultline »It seems to me, that at 10psi of boost , you are effectively loosing 10psi of fuel pressure , which means loss of fuel at wot in the stock set up. Just raising the fp 10 psi at at 10 psi of boost will keep your fp at a stock rate. What I do is raise the fp to around 100psi at wot, and 10psi of boost......and I havent had an injector fail in the last four years. Interesting direction. What's the easiest way to increase the fuel pressure? Because I don't think I need that much more fuel. Just a better 'comfort zone'.I just realized that this thread should probly be in the forced induction forum. Shouldn't it? My bad!

Unfortunately, their is no easy way to simply raise the FP. ...that I know of.FPR's ,(fuel pressure regulatorss) are used on fuel systems that have a return fuel line. After the fuel goes to the fuel rail and injectors , there is a return fuel line that the FPR sits on and maintains the proper FP, the left over fuel returns to the tank. We have a dead end fuel system. It does not return the fuel to the fuel tank after the fuel rail. The FPR sits in the fuel tank with the fuel pump, and returns the leftover fuel in the tank before in goes out to the fuel rail. The Top secret Turbo kit came with the replacement FPR for the stock one in the tank. It simply raised the FP to a constant higher level.MWR sold that kit, and you might ask them if they sell the fpr separately. I talked to Mat about 4 years ago and he said that they did not at that time, but they were trying to secure a deal with the company to do it. ...that was then...maybe they sell one now. Another option would be to tap a fitting into you fuel rail now, so that you could add you own return line. Most people return the line to the filler tube in the back for simplicity. Then you could add your own FPR at the fuel rail. Because the stock FPR would still be in the tank, you would have to add an inline fuel pump by the fuel rail to nullify it. Basicly, this is similar to my fuel system, except that my FPR returns the fuel back to only the fuel line befoe my additioned inline fuel pump. In order to do this their are some tricks with some pretzelled fuel lines and check valves to make it work right...and it is not so simple. It is simpler to add a return fuel line.You can get a FPR for less than a hundred bucks. You can get a FP for the same.My Rising rate regulator is simalar to a Vortech FMU (fuel management unit ).You can them for a hundred to a hundred fifty bucks. They only change the FP under boost. They let the stock FPR work under non boost conditions, then when the car goes into boost, they raise the fuel pressure. For every pound of boost, they raise the FP proportionately. The more boost you run, the higher your FP goes. If you get boost creep, it doesnt matter because the FP creeps allong with it. As the FP goes up , it feeds more fuel thru the injectors without the injectors changing their pulse width. I have run up to 14 pounds of boost on stock injectors without maxing out the duty cycle on the injector's pulse width....and running pig rich. The stock ecu doesnt even know what is going on and it is really cool In summary, I dont know of a FPR that you can use on our dead end fuel system, unless you replace the one in the tank. You can add one at the fuel rail if you add a return fuel line and an inline fuel pump.