Mustang 19lb injectors on m20 input, please?????

[nariusb]

I have 1989 525i with m20.
There's info about this but only for the big six engine.
I need to replace my injectors and I can get the Ford Mustang 5.0 4.6 19lb # injectors for cheap.
Could I do it without messing up anything and what outcome should I expect. I'm using stock 3 bar FPR.

[Bill R.]

compensate for a 20% increase in the injector size. I wouldn't do it.



I have 1989 525i with m20.
There's info about this but only for the big six engine.
I need to replace my injectors and I can get the Ford Mustang 5.0 4.6 19lb # injectors for cheap.
Could I do it without messing up anything and what outcome should I expect. I'm using stock 3 bar FPR.

[winfred]

it compensates for it ok but unless you need the extra fuel id just spend the money getting your orignal injectors cleaned and tested/ballenced, the 19# injectors will screw up the readings for the mpg on the obc on the m20 but they didn't really do anything to my 535s reading. i have the 19# mustang disc type injectors on my 90 325is but i have several mods

[nariusb]

I found a site saying:
"In order to ease the transition of any injector swap borrow a 325e fuel pressure regulator, rated at 2.5 bar versus 3.0 bar, and it will drop fuel flow by approximately 9%."
You can read it full here: http://www.teamdfl.com/bmw/e30/fuel/fueldflhtml.html

I do have porshe 2.5bar FPR to help ECM udjust.
Is this for real?




it compensates for it ok but unless you need the extra fuel id just spend the money getting your orignal injectors cleaned and tested/ballenced, the 19# injectors will screw up the readings for the mpg on the obc on the m20 but they didn't really do anything to my 535s reading. i have the 19# mustang disc type injectors on my 90 325is but i have several mods

[Blitzkrieg Bob]

http://www.fiveomotorsport.com/Injector_Sets.html

[Kobe Diesel]

Im looking to do the same with my M20 motor. My research (so far) has shown that a proper setup with 19# injectors should be used with an adjustable fuel press. regulator fitted with a gage, and an air/fuel ratio meter so that you can finely tune the fuel injection system to the ECU. Also, Ive read that "stage II" type injectors should be used, not "III". Not sure why, Im still investigating.

Ideally with larger injectors, you should also have more air getting into the engine so a M30AFM, bored throttle body and intake manifold porting/polishing is good to have. And of course a performance chip.

I think your Porsche FPR can work but you have to fit it so that the connections are sound and leak free. I dont know if Porsche and BMW share the same tubing and hose dimensions, if not then reducers/adapters are in order.

I ordered the Bosch book by C. Probst to further my understanding of the fuel injection systems -cant wait for it highlight it, cant wait for the summer time to begin the project.

[nariusb]

Yes, this porshe FPR is identical to 525i with 2.5bar pressure. I had it on already and the car ran good with stock injectors.

The web page, I quoted before, says I should use it to train or easyin the ECM and then go back to 3 bar FPR and the computer will udjust further.
This was done on 325i so I guess it should work on 525i.
I wonder if anyone has done this with their m20's?


Im looking to do the same with my M20 motor. My research (so far) has shown that a proper setup with 19# injectors should be used with an adjustable fuel press. regulator fitted with a gage, and an air/fuel ratio meter so that you can finely tune the fuel injection system to the ECU. Also, Ive read that "stage II" type injectors should be used, not "III". Not sure why, Im still investigating.

Ideally with larger injectors, you should also have more air getting into the engine so a M30AFM, bored throttle body and intake manifold porting/polishing is good to have. And of course a performance chip.

I think your Porsche FPR can work but you have to fit it so that the connections are sound and leak free. I dont know if Porsche and BMW share the same tubing and hose dimensions, if not then reducers/adapters are in order.

I ordered the Bosch book by C. Probst to further my understanding of the fuel injection systems -cant wait for it highlight it, cant wait for the summer time to begin the project.

[winfred]

i never bothered with the 2.5 bar regulator nor has anybody i know that's done the injector swap, just start it up and go for a good drive and let it adapt, every time you dissconnect the battery it will need to readapt

[Bill R.]

rated for 199 hp, the stock m20 produces 168hp, so the stock injectors are already sized 20% over what you need. With the 19lb you'll be approx. 40% over the stock flow. The dme has to shorten the injector pulse time accordingly to try and compensate for this to keep from making the engine too rich.
Too rich doesn't make power or efficiency. By using the ford injectors you get better atomization when they are used with the correct amount of on time, Injectors are more efficient when they stay on longer
With the lower pressure regulator, the better atomizing fuel injector that your buying doesn't work as well because higher pressures mean the fuel is atomized better making it burn more efficiently.
So to sum it up you go bigger injectors which have to cycle for a shorter time. Then you lower the fuel pressure so that they cycle longer but you affect the better atomization you get with higher pressures.
If you don't have something that pumps more air through the motor then the larger injector size is not a help its a hinderance. Have you put a header on it , or ported the head or larger valve sizes or done anything to require more fuel?






Yes, this porshe FPR is identical to 525i with 2.5bar pressure. I had it on already and the car ran good with stock injectors.

The web page, I quoted before, says I should use it to train or easyin the ECM and then go back to 3 bar FPR and the computer will udjust further.
This was done on 325i so I guess it should work on 525i.
I wonder if anyone has done this with their m20's?

[winfred]

i found a calculator online a while back that said mathmaticly the stockers are good for around 180 but i suspect they would hold up a little further, i think most people think you can stack the advertised hp additions and beleave they need more fuel with just a chip, muffler and hot air intake


rated for 199 hp, the stock m20 produces 168hp, so the stock injectors are already sized 20% over what you need.

[Jeff N.]

I'm begining to think "adaption" is a myth. After tinking with a MAF and wideband O2 meter for some time, it seem that the ECU works more like this.

- for a specific RPM + AFM voltage reading
- there's a target lambda held in a table in the ECU
- this target lambda generally ranges from slightly lean (ie: 15:1) slightly rich (ie: 13.5:1)
- the DME monitors the o2 sensor and attempts to adjust the injector pulse towards the target lambda. you can see this adjustment if you see your MPG gauge "bobbing" up and down. that's the ECU cycling and attempting to get it right.
- I have seen very little adaption in my system. Either the MAF voltage is right setting to get the O2 sensor to the right lambda or it's not. if it's not (ie: car is lean or rich vs. the target), the system will continue to adjust the injector pulse forever.

I have yet to see the DME get smarter over time. If IT does adapt, the adaption seems to be very very limited.

(Right about now Bill posts something from the depths of BMW documentation :D)

[Bill R.]

The numbers i quoted earlier are after converting to lbs perhour and then multipying by 10.2 the standard factor to come up with the horsepower capabilities per injector at a 80% duty cycle.http://www.bimmernut.com/%7Ebillr/images2/fuelinjectors2.jpg




i found a calculator online a while back that said mathmaticly the stockers are good for around 180 but i suspect they would hold up a little further, i think most people think you can stack the advertised hp additions and beleave they need more fuel with just a chip, muffler and hot air intake

[Bill R.]

think it is...I have the specs somewhere;) Its just a question of finding them, the adaption wasn't much. I'd really like to see some of these guys running the wide band to see what kind of af ratios they're really running.
I certainly don't think too many of them are in danger of leaning out.




I'm begining to think "adaption" is a myth. After tinking with a MAF and wideband O2 meter for some time, it seem that the ECU works more like this.

- for a specific RPM + AFM voltage reading
- there's a target lambda held in a table in the ECU
- this target lambda generally ranges from slightly lean (ie: 15:1) slightly rich (ie: 13.5:1)
- the DME monitors the o2 sensor and attempts to adjust the injector pulse towards the target lambda. you can see this adjustment if you see your MPG gauge "bobbing" up and down. that's the ECU cycling and attempting to get it right.
- I have seen very little adaption in my system. Either the MAF voltage is right setting to get the O2 sensor to the right lambda or it's not. if it's not (ie: car is lean or rich vs. the target), the system will continue to adjust the injector pulse forever.

I have yet to see the DME get smarter over time. If IT does adapt, the adaption seems to be very very limited.

(Right about now Bill posts something from the depths of BMW documentation :D)

[Jeff N.]

... to benchmark the O2 readings of a stock car with a wideband.

With mine, you can clearly see the cold run cycle with an initial richness, then the tailoff as the water temp warms, you can see when the mixture is correct to the lambda table (no back and forth adjustment on the mixture, just stays spot on), and you can see when you kick in the WOT trigger (goes to about to about 12:5 to 13:1, especially after 5k RPM).

Of course my car is far from stock so it makes it hard to baseline what the stock mixture would be.




think it is...I have the specs somewhere;) Its just a question of finding them, the adaption wasn't much. I'd really like to see some of these guys running the wide band to see what kind of af ratios they're really running.
I certainly don't think too many of them are in danger of leaning out.

[Bill R.]

.
... to benchmark the O2 readings of a stock car with a wideband.

With mine, you can clearly see the cold run cycle with an initial richness, then the tailoff as the water temp warms, you can see when the mixture is correct to the lambda table (no back and forth adjustment on the mixture, just stays spot on), and you can see when you kick in the WOT trigger (goes to about to about 12:5 to 13:1, especially after 5k RPM).

Of course my car is far from stock so it makes it hard to baseline what the stock mixture would be.