Fuel injector change for FE...

[jonzobot]

Thanks for this valuable input.

I'm not sure I want to go the way of ecu calibration - I guess it depends on difficulty and cost for this vehicle. I know some people do it when adding turbos. I think I might spring for sending in the injectors to be balanced and flow matched though.

[t vago]

Originally Posted by Galane

For some V type engines, changing the way the fuel rails for each bank re connected can make a significant difference.

One example. On the 2004 and earlier Dodge Dakota with 4.7L OHC V8 the fuel enters in the middle of the left rail. The front of the left rail is connected to the front of the right rail. Right rail fuel, especially to the rear two injectors, has much more time to get heated up. There are two fixes for this, one fairly easy one not so easy.

The not so easy method involves buying more injector rails and a second cross connection pipe then modifying the rails to connect at both ends.

The easier method involves installing a T into the fuel line then running a high pressure hose across to the fuel pressure test/bleed fitting in the middle of the right rail. Nothing has to be removed except for disconnecting the fuel line so it can be cut for installing the T.

Either mod evens out the pressure and temperature of the fuel. Dunno if anyone has done both mods.

Some who have done one of those mods say they've gotten measurable HP and torque gains at the rear wheels on a dyno, as well as better MPG.

I did the not-so-easy fuel rail mod. Worked wonders.

[Galane]

Originally Posted by t vago

I did the not-so-easy fuel rail mod. Worked wonders.

Details please!

[elhigh]

Originally Posted by jonzobot

Just to be clear, my plan is only to increase to the voltage of the fuel pump to help maintain fuel pressure to its factory spec.

Is there not a separate fuel pressure regulator that you could adjust?

[t vago]

Originally Posted by Galane

Details please!

Well, for starters, I apparently am the first to have documented this not-so-easy method, waaaaaay back in June 2010.



Details are here: Dakota-Durango: Does anyone here use fuel rail cooling?

I remember coming up with the idea to do something about fuel temperatures after dealing with yet another instance of heat-soaked lack of response. Somebody else in that thread actually mentioned feeding the two banks independently, as a possible way of equalizing fuel temperatures.

Apparently, Summit Racing now states they do not recommend the Twist-Tite stuff for fuel use. I therefore recommend fabricating the fuel hoses out of braided nylon hoses and hose ends.

[greasess]

Just to clarify, your existing injectors can't be flow matched. Companys who sell matched sets buy large amounts of the same injectors, test them all, then make sets based on the results. They don't change the flow characteristics to accomplish this. I'm not aware of anyone who sells matched sets of injectors as small as yours. This is a great resource for understanding injectors a bit better.

[hat_man]

t vago.... How did you find a comprable fuel injector? I know this is a rather open ended vague question, but did you just find the parameters of your stock injectors and then check RockAuto one by one until you found what you wanted? I have wanted to do this swap on my Ranger for a long time but am completely uneducated on the technical stuff. I can turn a wrench really well, but don't want to make any mistakes in sizing. When I look on RockAuto I can't tell how many holes the injectors have. I still have the stock single hole ones so even a 4-hole would be an improvement. I would love more holes if possible. Also isn't there a diference in high impedance and low impedance injectors. Not sure which I have (low I think) but I'm sure they aren't compatible. Any insight you have would be great.

Thanks

[hat_man]

I would love to swap my OEM ones like these

More Information for MOTORCRAFT CM4779

with these

More Information for STANDARD MOTOR PRODUCTS FJ462

But the shape is a bit different and the electrical connection also looks different. There may be electrical adapters available but I don't know about the shape and length. The OEM ones look shorter than the other ones.

[BLSTIC]

Does anyone like Injector Dynamics match small injectors at multiple points? If I were to upgrade an older engine from single point, I would probably be flow balancing the rest of the engine.

Actually I shudder to think, on a 302HO inlet manifold flow @28" can vary by 25% runner to runner. Assuming that makes a 10% dynamic airflow difference and the injectors at low pulse-widths can vary by another 10%... that makes for a potential air-fuel ratio mismatch of 22% or so. Which with a target of 14.7:1 is a range of 17.9-11.4:1

[mazdamx640]

I'm interested in putting 12 hole injectors on my 99 f150 4.6 I know the stock is 19lb but not sure on body or electrical connector any idea on what might work?