B20A injectors?

[blitz_power]

Is b20A injectors direct bolt on into the city?
I found a set of four. I hope members can help me out so i dont get the wrong thing..
Thanks

[QikLude]

I can check if you wish, i have lots of the injectors and a city injection loom out of a car sitting in the shed somewhere...

Might try that, in theory they look very similar.

Jw

[blitz_power]

i was almost going to buy but just waiting for members to help.. I just worry after i bought and cant fit in.. Plus the item is ship from New Zealand.

Do i need the fuel rail too?

[James]

I asked Boostboy about this topic not long ago and he assured me that they do bolt straight in but because of the bigger injectors the engine runs very rich at low revs unless you can do something to your computer or your fuel pressure to get less fuel in there.

[QikLude]

the computer *should* turn the fuel down.

If you have a stuffed oxy sensor then it wont be able to lean it out and will give you a richer mixture.

Might be worth a new oxy sensor.

Jw

[blitz_power]

Where is the OXY sensor located?
Thanks

[BOOSTBOY]

The main purpose of the oxygen sensor is to trigger the computer into going into closed loop mode.  It wont help with the compensation of more fuel from bigger injectors.

To get the best out of these injectors you'll need to do some work with the computer or else put up with a drop in low RPM drivability.  The same theory applies with any car that has had its injectors upgraded without a change to the computer running them...

But remember this is all my theory, not actual experiance as i have never used these injectors on a CityT.  Trying to locate a set now and then i'll be able to make up an ECU map adjuster which should be able to 'tune' these big squirters...

[QikLude]

[quote author=BOOSTBOY link=board=GEN;num=1055737563;start=0#6 date=06/17/03 at 20:29:09]The main purpose of the oxygen sensor is to trigger the computer into going into closed loop mode.  It wont help with the compensation of more fuel from bigger injectors.
[/quote]

I dont think your right there dude.

The computer will go into closed loop mode IF it cant get a correct reading from the oxy sensor.
It relys on the oxy sensor for running "feedback"
Fuel injected cars adjust there mixture on the fly by check if the air/fuel ratio or 'stoich' ratio is correct, thus ensuring a clean burn/good power etc...

closed loop mode is an overrich "failsafe" mode programed into the ECU for limping back to the garage to get fixed.

The oxy sensor/s is a very important part of any injected car and even more so to problem prone FI cars like citys.
An oxy sensors lifespan is only rated under 100,000ks so most citys one will be WELL stuffed.
So the cars will chew more fuel and produce less power..

Factory ECUs will compensate for larger injectors and toher things quite well, up to a certain %... or with an aftermarket one you keep altering the % until you get the correct fuel/air ratio.

I done a fair bit of ECU work along with the associated tuning / testing messing about etc..
One thing i have learnt is the importance of the good old oxy sensor.

Blitz_power - The oxy sensor is in your exhaust just after the turbo somewhere, kinda pointy thing with a lead and a plug on it...
You can test if its working ok with just a simple multimeter. I can dig out a site that will give you details on that if you wish?

Jw

[blitz_power]

Hi there..

Qiklude, I have throw away the sensor since i change the full exhaust. However when i bought the car, the wire is already broken, you mean that the oxy sensor is quite important... Should i put back another one? I dont know where to find another oxy sensor..

ANy ideas... please let me have a link on the oxy sensor.. Currently i found out my car sometimes it has the power and sometimes its not. I am not sure what is happening..

Plus on the oxy sensor plug i have connected to the boost gauge light.. So this mean the sensor plug is sensing the boost gauge light?

Thanks..

I am now thinking to go further modifications for my car,, just thinking how to do the internals as its quite hard to get parts..

Been spending around 3000 to fix up my car and accesorries.. really sometimes dont know how much i should sell the car in future.. anyway i think as long as i got the timing i want is enough during the quarter mile..

Target is High 13 seconds is enough..

[QikLude]

The oxy sensors on citys are just single wire units from memory?

So go to the wreakers and find one out of a civic or something. The most tidy one you can find.

A good auto shop will sell you one for around $100-$150 this is the best option.
They all run the same thread into the exhaust, you just need to put the right bung in the exhaust.
The closer to the turbo the better to, so it can sense changes quickly.

Running the boost light off that wire is not a good option! That could definatly cause you problems!

yeah parts can be a problem, im just getting my city head completely mahcined up at the moment, and Im rebuilding the bottom end as well.
Just back to standard, except for the head, which is being "tinkered"

Im finding so much rust in the citys body its not funny, it WILL be the most mint one by the time im finished I hope!

Cheers

[BOOSTBOY]

QikLude,

I agree with what you are saying there for sure, the engine management system is definately dependant on the oxygen sensor.  But, as for accomadating larger injectors, the stock management wont be able to produce a factory-like result, the 'point' is fairly low.
Closed loop is the mode at which the ECU will go into when under light load such as at a constant cruising speed.  If you monitor the voltage produced by the sensor it will cycle up and down when these conditions are met, which the ECU recognises as a closed loop signal.  Thats how i understand it anyway!

On the city the oxy sensor is mounted in the exhaust manifold, 'before' the turbo which is quite unusual.  The sensor 'after' the turbo is commonly mistaken for the oxy sensor but is the cat temp sensor...

[Charles]

B20A injectors do not bolt in. The tops are completely different. I have used them and had to machine holes in the fuel rail to allow them to fit in (about 5mm across and 3mm deep), you also need to mill the same depth off the phenolic spacers (3mm).

The City turbo ECU runs the B20 injectors fine. However you only need them if you are running big (massive)boost.

The closed loop does not work when it comes on boost and it runs very rich when cold before 02 sensor warms up. Even on 26psi with a big turbo the mixture stays very rich at around 10-11:1

[BOOSTBOY]

There you go, I stand corrected...

[QikLude]

good info

I was going to try it out this weekend, guess I wont now!

Ill just keep welding out rust  >:(