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stedee · Alfa 33 Joined: 02 May 2006 Posts: 364 Location: brighouse

hi
i am after some new injectors for my 33 16v, does anyone know where to get them from also i have used the equations about which injectors to use which state that the injectors only work at 80% efficiency and that site is basically saying that the standard ones arent good enough,
i found a site but they dont sell the ones i am after which are the cream tops which i think equate to 45hp per injector or 40 , cant remember
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tvatavuk · Posted: Wed May 02, 2007 8:13 am Post subject:

Hi steede,
Long time ago in galaxy far far away....ahm Smile

on old AR33 disc list one of very acitve members transplated injectors from OPEL/Vauxhall Astra/Calibra/Omega 2.0 engine. Car went like rocket but problem was it consumed fuel like rocket too.
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Corin · Alfasud Joined: 28 Aug 2005 Posts: 55

Is your car standard or uprated? If the injector only ever hits 80% duty cycle it is perfectly fine for the job, I had my injectors cleaned by a firm, i can get you details if you want, you post them injectors and cheque and they service and clean, was about 45quid from memory, a recommended firm, fast turn around. If car a daily driver i've a spare set you could borrow, get done then give me your old ones after swapping. If uprated you may need to look at others if injectors hitting max duty cycle. Is this what you mean by efficiency?

Corin

stedee · Alfa 33 Joined: 02 May 2006 Posts: 364 Location: brighouse

hi guys thanx for the replies
corin yes it is what i mean by 80% efficiency,
i have ported the heads ,had them skimmed and also i have done a mod on the inlet valves so the results should be like there is a high lift cam, this involves shaving away part of the radius on the valve so there is more of a gap when the valves are open.with these mods the engine should breathe easier so i thought i will be able to add more fuel as there is more air getting in the cylinders also i know my injectors are naff, i was debating getting them cleaned but after reading about the 80% duty cycle (efficiency)i am swayed into getting better injectors.
i have done a bit of research into the fuel system and i have found out the fuel pump only operates at 2 bar so will i need to uprate the fuel pump and the regulator to put on some as tvatauk said opel/vauxhall injectors which either operate at 2.5bar for the cream tops or 3 bar for the red tops which have a special spray pattern for 16v engines.
i did know of someone with a seriously quick 33 16v( it did 160mph on the motorway , and i`m not blagging i was in the car),we couldnt work out why it was so fast (it wasnt the chip or the cams) now i`m thinking maybe it was the injectors, - i hope so cos if mine goes that quick i will be well happy.
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Corin · Alfasud Joined: 28 Aug 2005 Posts: 55

Seem to recall you can run an injector at upto 95% duty cycle without problems, at least that's what i remember from reading through on the lancia forums, but cant be certain i guess. They jus need to be clean and working. You may find the fuel pump can run higher if you change the regulator settings as it is the regulator that decides the fuel rail pressure. Saying that, i don't know what the max pressure that the pump can provide, as it's not an in tank pump it should be fairly easy to replace if not able to take the pace. Sounds like you should have a pretty fun motor though, good luck with it!!

Corin

BigAl · P4 Joined: 06 May 2003 Posts: 2996 Location: U.K Surrey

Hey Steede
Do you still have a standard ECU? The ECU will work within ranges from 2.91 (normal) to 3.3 (max) any higher and the ECU thinks theres a problem. Im not sure how to change the regulator, so was thinking of getting a FSE power boost valve, ups the pressure in relation to load. There is also a problem of bore wash if the pressure is too high.
You can also aid in breathing by using the 5 min AFM mod, you reduce the load on the spring holding the flap in place so the flap opens easier.
Funny you mention all this as i too was reading up on fuel system (after market EMS / ECU) but at £500 was a bit steep, so was thinking of getting my injectors serviced.
Have alook at http://www.emeraldm3d.com/ems.htm#programems
for a good read
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Corin · Alfasud Joined: 28 Aug 2005 Posts: 55

Regualtors are fairly easy to change, they have a cap pressed in place that you prise out with a flat driver or similar, then this reveals a screw that you use to adjust the rail pressure. You need a fuel pressure guage though, there are some that you just T piece into the fuel line and blank when not in use, look on ebay, or you can get more expensive ones that are electronic so you can have a constant reading in the car rather than under the bonnet. Take car when plumbing them in, the sytem holds pressure well and petrol squirted into the eye at two bar stings somewhat Shocked

I'm doing hes mods on my grale at the moment so bought an electronic one, £120 though, ouch

Corin

stedee · Alfa 33 Joined: 02 May 2006 Posts: 364 Location: brighouse

thanx for the tips guys
yeah big al i have done the afm mod and i will probably get the fse power boost thingy but i think that just replaces the regulator, the regulator is attached under the inlet plenum next to where the accel cable is held and is ok to change if you dont mind petrol pi**ing everywhere.
thanx corin i will have a look at the regulator, i might have a play with it but i have decided to get some of the opel/vauxhall cream or blue injectors for a 2 litre sri engine, if i cant get the injectors to work i will get an uprated fuel pump and regulator and later on when ive got the cash i will get it chipped.i think that guy who does the squadra chips is meant to be ok if you can get to belgium, he will remap it to your individual car.
btw have you guys noticed the difference between running on normal unleaded and the 97 or 99 ron, it makes a big difference in my car
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BigAl · P4 Joined: 06 May 2003 Posts: 2996 Location: U.K Surrey

I forgot to mention that the ecu is clever enough, with the help of the lambda sensor, to shorten the duration of injuction cycle when the fuel pressure is increased. Would this help to bring down the duty cycle figures enough steede?
I have heard the the FSE power boost valve doesnt make that much power difference, only makes car smoother on acceleration / deceleration, anyone know?
Thanks for the tip corrin RE: the standard regulator. Would it not be possible to adjust this with an ecu tester connected, reading off the fuel pressure? It would save connecting a meter.
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stedee · Alfa 33 Joined: 02 May 2006 Posts: 364 Location: brighouse

i have no lambda on mine btw and the power boost valve is meant to decrease response times. ie instant pick up
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Corin · Alfasud Joined: 28 Aug 2005 Posts: 55

Sorry Al, never saw the querstion there! Is the ECU able to give a reading for fuel pressure? Is it clever enough to compensate, thus undoing any change you've made? My experience of changing pressure relates to 'chipping' my grale, where the new chip map is compensated by increasing the fuel pressure via the regulator adjustment screw. I must admit i've never even tinkered with the alfa setup. So am honest (and slightly sleepy) answer would be 'i dont know...' Confused

Corin

BigAl · P4 Joined: 06 May 2003 Posts: 2996 Location: U.K Surrey

No worries Corin, according to an Alfa mechanic of many years and many years my senior, he was the one who said

stedee · Alfa 33 Joined: 02 May 2006 Posts: 364 Location: brighouse

i hope thats not the case because i ahve just bought a set of red top injectors of a calibra and fuel pump, i will tell you how i get on when i fit them
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stedee · Alfa 33 Joined: 02 May 2006 Posts: 364 Location: brighouse

just had a thought for you guys with cats, there is a throttle sensor on the throttle body that measures throttle input when full throttle is sensed the lambda sensor is bypassed so if you shorted the the 2 terminals it should ignore the lambda all the time and therefore not try to adjust the fueling, i think the 2 terminals to link are the middle and bottom (there are only 3 )
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BigAl · P4 Joined: 06 May 2003 Posts: 2996 Location: U.K Surrey

would that not interfere with the throttle closed possition for the ecu, therefore messing up cold starts and idle ect?? not sure though. I think the easiest way would be to change the relay type connector and set it up for 95/97 ron no cat but then wouldnt that ruin the cat?
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stedee · Alfa 33 Joined: 02 May 2006 Posts: 364 Location: brighouse

i wouldnt of thought so - why would it ruin the cat?
and where is that relay looking thing which is a switch really, i`ve looked for it b4
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BigAl · P4 Joined: 06 May 2003 Posts: 2996 Location: U.K Surrey

have a look at http://www.alfa-pages.co.uk/viewtopic.php?p=15481&highlight=#15481
Its by the battery and the relay goes into a red coloured plastic thingy. if the cat isnt getting emissions within a specific range it has to work harder, just thought it would degrade it quicker.
Doh, looks like my pic is not there, ill take another and email it to you.
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mt · Posted: Wed May 16, 2007 10:50 am Post subject:

stedee · Alfa 33 Joined: 02 May 2006 Posts: 364 Location: brighouse

hi mt, it picks up quicker
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mt · Posted: Thu May 17, 2007 2:49 pm Post subject:

BigAl · P4 Joined: 06 May 2003 Posts: 2996 Location: U.K Surrey

stedee.
How did it go, did it make any difference?
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ZeNiTh-PbArM · Posted: Mon Sep 08, 2008 11:24 pm Post subject:

Hi,

just to make things clear please consider the following statements before tinkering with your injection system :
- the ECU cannot read the fuel pressure. However, oversize injectors (or AFM adjustment or any other means of fooling around with fuel control) will cause overfueling of the engine, which can be corrected (up to a certain point) by the lambda regulation loop (where applicable). The target regulation value hitting upper and/or lower limits will result in the ECU generating fault codes and entering failsafe mode - definitely not the best way to get more HP out of the engine
- increasing fuel pressure will not improve fuel delivery to the engine much, if at all. This mod will quickly ruin injectors and fuel pump ; moreover the injector spray pattern is designed for nominal pressure operation. Let this mod for racer boys and spend your hard earned bucks elsewhere - you should know better
- increasing fuel flow to the engine without improving flow is useless, it's like running on choke on a carbed engine. Best engine efficiency is achieved for a given fuel to air ratio. Richening the mixture a little will result in a small performance improvement ; richening it a lot will for sure shorten your engine's life and will not yield any performance improvement. Air flow increase can be obtained by one or more of the following means :
- removal of the AFM and inlet manifold (wich cause a restriction at inlet). this mod requires modification of the injection system as the engine ECU still needs to know the intake air flow to operate properly
- intake ducts and head porting
- race exhaust manifold and free-flow system
- bigger valves
- more aggressive camshafts
- over-revving capability
Trying to add more fuel to the engine without one of these mods (or similar) is simply useless and counter-productive.

And by the way, as RPM increase, available injection time between cycles decreases. Under full load at high revs, injectors can reach 100% duty cycle but most of the time they have been designed to allow for a little security margin and max duty cycle is around 85%. However, permanent activation during a few seconds will not damage the injector itself provided there is sufficient fuel flow through the injector to cool it.
Before fitting newer injectors, ask youself how much more air flow you have and you'll know how much more fuel flow you need. Most of the time you'll need a remappable ECU to go along with the mods anyway

regards,
zp

gritsop · Posted: Tue Sep 09, 2008 11:45 am Post subject:

Thanks a lot ZP ... Thumbs up for the useful info!
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Admin · Posted: Tue Sep 09, 2008 3:47 pm Post subject:

Hi

Or in simple terms, dumping more petrol in doesn't give you more power. Other mods can give you more power and those mods might require more petrol.

All the best

Keith
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BigAl · P4 Joined: 06 May 2003 Posts: 2996 Location: U.K Surrey

ZP,
how restrictive is the current plenum chamber and AFM.
Is it possible to remove them both and replace with a MAF on one of the throttle bodies and fitting air filters for each of the throttle bodies, would this allow for more airflow and then more fuel?
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