3 or more injectors

[edge]

hey guys probably a stupid question can you run mor than two injectors
off the standard ecu i was told you cant but was never told why if some one could help that would be good

[iXNAY]

there is only room for 2 injectors in the TBI set up.
the only way to get more is to goto MPI :D

[ProZac]

Edge, the car in your avatar looks familiar... Was it featured in a readers rides section of an NZ car magazine a couple of years ago?

[WidebodyWoody]

He is asking about the computer, not the TB.

No, the computer is only setup to give signals to only two injectors. You can hook up the third injector to one of the two injectors wires ONLY your car would run COMPLETELY rich. it would be pumping out a exactly half the amount of fuel that is already being pumped into the inlet.

The answer is straight out NO.

Unless you get some sort of MAF translator or piggy back computer. Otherwise you need to go Aftermarket. (fuel injector pro offer a setup that allows either 3 or 4 injectors into the standard TB and it comes with a computer thing that allows you to use the standard computer.

http://www.fuelinjectionpro.com/
http://www.angelfire.com/mech/edwardcase00/83kit.html
http://www.angelfire.com/mech/edwardcase00/tbkit.html

(I don't think these are the actual kits that I am talking about though)

[mrcordial]

If you want to add an extra injector, you can tap it into your cooler piping just before the throttle body.

Also, you can controll it via a microtech digo pro fuel only computer for example or a cheaper soloution is to use a jay car digital fuel pulse adjuster ($90) or something along those lines and tune it to spray fuel when in higher boost for example 20psi :beer

[edge]

prozac yes it was in fast fours but looks different now i also want to make a new rear and frount bumper.ok it is posible to add another injector just
wire in to a existing injector. which injector is the main one in the wiring diagram. i think it will be no 1 injector am i right? also how to wire up parallel or series.thanks

[edge]

i have just had a play around with some old injectors off a vr4 and a old starion computer and i have had all 4 injectors working even when reving up you can hear the injectors tiking faster i think this might work

[Junkers]

I've always wondered about this, if you used 4 vr4 injectors and a Type A injection ecu (syncronised injector model) whether you could run two 450cc injectors in parallel off one 850cc input. Would there be enough current to drive them both and can you run the starion without alternating injection and still achieve good results?

[jakobsladderz]

I'd say that the ECU could drive them but you'd need more resistors (if you choose low-z injectors). If the injector driver can drive 1 amp it should drive 2amps OK (I guess I'm saying it would most likely have been overengineered). You can check how warm the ECU box gets when running them It won't kill it instantly, it'll just get mighty warm if anything is wrong..

Biggest problem is that it's not only the flowrate that changes from injector to injector, the opening time also varies. Opening time changes will affect the idle mixture more than anything else..

It may work, it may not. If it works, great, if not you have to swap injectors to change the flowrate. Doesn't sound like an easy task, but if you are trying to save a dollar or 200, it may work.

[edge]

i will run tonight and see how hot it gets can any one tell me about the difference in injectors what type are starion ones and what type are vr4 injectors

[jakobsladderz]

Using a multimeter to measure the resistance across the pins on the injector a high-impedance injector (safe to double up) will have a resistance of greater than 13 ohms (1 amp current draw or less). A low-impedance (needs resistors/low-impedance drivers) will be less, usually they are 2-3 ohms.

if yours are low-z you'll need to put resistors in series with each injector

use 2 20ohm, 5 watt resistors in parallel to make a 10 watt, 10 ohm resistor to put in series with each low-impedance injector. This effectively makes them high impedance injectors.

Starion injectors are low-impedance (hence the resistors near the airbox). VR4 injectors are also I think but it'll pay to check..

Try at your own risk though, I haven't tested the ecu myself (to be sure all will be well you'd need to get the datasheet on the output transistors and check their rating).
Easy...

Duncan

[edge]

i have had the car running and disconnected 1 injector (standard starion one )so it will idle then i joined all injectors together in series then i ran another wire from the battery straight to the injectors then the other wire i connected to the signal wire from the ecu.I done all this with the car running when i connected the signal wire the car droped slightly in rpm but still whent and all the injectors were ticking i then riged up a old fuel pump to the injectors and had water squrting out of the injectors

[jakobsladderz]

Carefull running water through injectors and fuel pumps. It may not do any damage straight away but they'll rust after a couple of days. Be sure to pump methylated spirits through them first (metho absorbs water really well) then kero to coat everything. You really don't want water in there long-term.

Did you check if the ECU box got warmer than usual running all the injectors off it or not?

[edge]

yea i checked that i took the cover off nothing got hot i also ran the injectors for about 20 min all was good have to go to the wreckers and get a manifold now

[RiceThief]

If you were planning to run 4 injectors with the starion ecu with the intention of running multipoint wont you have the issue with the timing of when the injectors fire?