the search for the truth about our injectors

[Bean]

So I've been pondering about injectors lately and after gong back and forth with the manual and various sources on the net - I'm non the wiser.

I have a stock bigport EU-spec bluetop and the injector colour is blueish.
according to various sources these are 210cc low ohm (2.4Ω @255kPa (~37psi) - according to the manual stock pressure is 38-44psi though, except @idle therefor actual cc would be more like 221cc (@41psi).

same goes for the 7MGE low ohm injectors which are rated at 295cc (also @255kPa) and would there for be at 310cc (@41psi).

41psi is the average of the fuel pressure at the rail according to manual - as I don't have a suiting gauge to measure it I used that. Now it would be nice to know what the actual pressure is - I'm aware that due to age the results will differ from engine to engine or rather fpr to fpr.

anyway did anyone measure fuel pressure with the stock fpr (vacuum disconected) or could do it?

alternatively but probably more unrealistic - did anyone get the stock injectors ever flow tested and if yes what were the results and crucial at what pressure?

I'm asking all this as I have a though time to source some injectors localy as most cars around here run carbs and those who don't use side feed injectors.
If my above theses is correct I could try and find another fpr and raise fuel pressure to 4bar (58psi) which would be sufficient for me to start tuning my new engine as that should be able to support up to around 165hp. I'm not particularly a fan of raising fuel pressure as this introduces more heat to the fuel in most cases, same as a fuel pump which delivers more fuel than necessary. This as a remark for all those with 255lph pumps (100lph @3bar is more than enough to power 230+hp).

Time for a beer now hope to get some factual input back from the community.

Best regards and have a good week

Bean

PS: here some resources:
http://lextreme.com/Injector%20data.htm
http://www.toysport.com/webpages/techinf...ectors.htm
http://www.gtsparkplugs.com/InjectorSizeCalc.html

[jondee86]

FSM specifies FPR pressure 38-44 psi at no vacuum (= WOT)
184-196 cc/min for MAP engine (low impedence injectors)
200-212 cc/min for AFM engine (high impedence injectors)

If you want more, I would suggest GZE injectors (365 cc/min IIRC).

And a few more references...

http://www.witchhunter.com/injectordata1.php4
http://users.erols.com/srweiss/tableifc.htm

Cheers... jondee86

[Bean]

that's were the root of all evil lies - I've seen those figures and if you go on to check how it's tested the setup will be at the 38-44psi but all other information including from Toyota (outside the FSM) says different.

did you ever do that 15sec test?

tried to test the resistance of my injectors today but was inconclusive (6.6Ω main and 8.0Ω cold-start) - might have been the heat or my multimeter is past it's accurate lifetime after all the abuse it took (maybe time to get a Fluke or other proper brand unit).

EDIT: if you look up the blue and dark blue ones in your second reference link you'll get what I'm talking about - as both don't match the FSM.
I'm not very good with colours but I'm fairly sure I have the blueish ones (with a hint of green in them, could be fade due to age)

your first link doesn't help too much as I have no idea about what part number to look at and there are too many densos to click through
guess the number is on the injector but can't be bothered to take one out right now. already too hot again here to work on the car

[oldeskewltoy]

Jondee... the US AFM injectors are low ohm(at least all the AE86s), not high ohm. I can't speak to other markets

A few tidbits of info I can offer to help further muddy the waters...

1) US AE86er (forgotten whom) had his OEM US injectors checked and cleaned they were 210 @ 3 bar

2) long time ago... when I first checked into larger injectors, Russ Collins (the RC of RC Injection) told me he had never actually found a 210cc Toyota 4AG injector. all the ones he ever found flowed 185cc

This is what I know....

find a mid to late 80s fuel injected Honda Accord, or Prelude(2.0 efi). If the injectors are beige/tan, they are low ohm and 240cc, and a perfect upgrade(once cleaned and flowed) to a4AGE on 256, or even a 264 cams running on stock electronics

[Bean]

yay more confusion got to love cars and the internet.

[jondee86]

Yes... I've seen where the USDM AE86 uses low Ohm injectors, whereas
my (Euro spec I believe) AE86 runs high Ohm injectors*. Kind of like the US
got AFM and the Euro spec got MAP sensored engines.

Now that I have a smallport installed with cams, ITB's and aftermarket
ECU, I thought I would check the duty cycle. It's hitting around 80% at
8000 rpm with WOT, so it seems the stock injectors (235cc high Ohm) are
are doing the job.

Cheers... jondee86

* Assumed to be high Ohm as there is no resistor pack. However, apparently
there were some factory ECU's that could run low Ohm without needing
the resistor pack. Perhaps I better check that out...

[jonis79]

jondee86 Wrote:FSM specifies FPR pressure 38-44 psi at no vacuum (= WOT)
184-196 cc/min for MAP engine (low impedence injectors)
200-212 cc/min for AFM engine (high impedence injectors)

On my EU (Switzerland destination) hachiroku is AFM. There is low impedance 216cc injectors (23250-34030) from factory.

[Bean]

jonis79 Wrote:

jondee86 Wrote:FSM specifies FPR pressure 38-44 psi at no vacuum (= WOT)
184-196 cc/min for MAP engine (low impedence injectors)
200-212 cc/min for AFM engine (high impedence injectors)

On my EU (Switzerland destination) hachiroku is AFM. There is low impedance 216cc injectors (23250-34030) from factory.

Do you have proof for that? Did you ever measure it? Also do you have the CAT version or not. Mine is a Swiss non CAT kouki version.

[jonis79]

Mine is 85' zenki not CAT. Now I removed intake manifold and injectors and they are blue with numbers 23250-34030 (http://www.witchhunter.com/flowdatapix/d...4030.jpg). I measured resistance (~2.5Ω.
On my donor car (EU MAP kouki not CAT) 23250-16010 dark grey injectors.

[Bean]

Thanks for the input