Fuel injector change for FE...

[cRiPpLe_rOoStEr]

Originally Posted by ar5boosted

Recently, Direct-Injection has taken over port injection. These injectors are even finer.

The general assumption is that 'nothing has changed' with Injectors over the last 20 years but actually these continual tooling improvements really have changed fuel-injectors dramatically. It also explains why modern cars are getting so much power than before because the injectors are working better.

IIRC direct injection also tends to operate at a higher pressure, since there is a shorter gap for the fuel to fully vaporize compared to conventional port-injection.

[jonzobot]

So, a wee update to this.

I checked my computer with a scanner, and I appear to have stabilized at -20% long term trim. A bit more than expected. This makes me think these injectors are 220cc. But, my check engine light is still off; I figure I have another 5% of trim before the switch is tripped.

My longer trip of 200km was made with the alternator ON, which is unusual because I normally use this car to commute and have the alternator off. So, with a grand total of about 300km on the new injectors, most of which is with the alternator on, is a bit screwy on the latter third of this tank. I have previously found the alternator delete helped my mileage about 10%.

Further complicating all this is that a higher bus voltage from using the alternator should serve to help atomize the injector spray and help exaggerate the effect of the new injectors.

With all that said, my best tank before this was 4.1 l/100 km; and I just filled up and measured 3.99 l/100km.

That's a 900 km tank with 1/3 of which on the new injectors, albeit largely with the alternator on during that last 1/3.

Things are looking promising for the next tank....will keep you posted. Regardless of what happens I am just happy I have joined the <4 club

[t vago]

30.5 MPG!

That was my current trip fuel economy this morning, going into work. The trip odometer and fuel gauge needle are still tracking each other in a manner that supports this elevated fuel economy gain.

Never have I looked forward to filling the tank as I am now.

I also bought another set of these fuel injectors for the Dakota. The ones I installed into the Karen-Mobile were lying around for about a year, and were originally meant for the Dakota anyway. I received them yesterday, and will be installing them into the Dakota tomorrow.

(Yesterday's number was 28.2 MPG).

[t vago]

Some updates -

The Dakota now has a set of these fuel injectors, and runs as nicely with them, as do both my Magnum and my Durango.

Finally filled up after the Magnum dinged on me today. Went 410.7 miles on 15.017 gallons, for a tank fuel economy of 27.4 MPG. The MPGuino now under-reports fuel consumption by about 1.4%, where it used to over-report by about 4%. The MPGuino reports that I got 27.5 MPG. Not quite the 20% I had figured (and had secretly hoped for, to be honest), but still...

This is a improvement of 11.6% from the previous tank (02 July fillup) in which the old fuel injectors were used, and an improvement of 4% from the immediate last full tank that I put in two weeks ago.

[cRiPpLe_rOoStEr]

Sure it's far from being a negligible improvement.

[93tracerwagon]

I'd like to upgrade our 2007 Dodge/Jeep 3.7 v-6 I believe the original are 2 hole. 4 hole are pretty easy to find but cannot find 12 hole.

[ksa8907]

Originally Posted by t vago

Unfortunately, the only 12-hole injectors I have found are rated at either 22 lb/hr (0280156336) or 24 lb/hr (0280156161), and they only have the EV4 wiring connector on them. Maybe somebody else can chime in.

how do you find this information? I have searched high and low and i cant find anything about the flow rate of the stock injectors.

[JMB#7]

I have had a similar experience on a 2001 Jeep Grand Cherokee with the 4.0 liter inline 6 cylinder. In that case, the stock injectors were single hole, which I swapped out for Bosch 3rd Generation EV6 4 hole injectors of the same flow rate. Fuel economy did increase by about 1.5 mpg. But the bigger benefit was smoother idling, quicker starts, and better modulation of the automatic transmission. I also run the Autolite double platinum plugs APP985 and a K&N drop in filter with this set-up. (Please note that the filter & plugs had been in place prior to the injector swap) I do know that on some Jeep forums people will report an initial increase in fuel economy, but then it drops back closer to the previous mpg after the computer does a little "re-learning". In my case, it has sustained better economy. In general, more holes at the same flow rate will improve atomization at idle and partial throttle conditions. The peak horsepower or full throttle conditions will likely not change since there is plenty of turbulation under those conditions. I have also installed 4 hole injectors in a 1995 YJ Wrangler with the 2.5 liter 4 cylinder & manual transmission. There was not any appreciable fuel economy gain, but it started better, and ran much smoother throughout the full power band.

[jonzobot]

Bad news for me; I filled my tank today. There was no change in overall fuel economy. That said, this was another abnormal tank with lots of highway driving with the alternator.

1002 km / 40.84 L = 4.1 L/100km

My next plan is to increase the voltage to the ignition, injectors, and fuel pump to 15v or so. Theoretically they should spray better at higher voltage/pressure.

Possible reasons for a lack of results include the flow rate of the injectors being too high, I picked an out-of-balance set, and/or the natural variation between tanks offset the gains from the new injectors. And, of course, the possibility that a change of fuel injector design in this engine is not sufficient to cause any meaningful change in fuel economy.

Too bad you can't do an ABA test with injectors (fuel spill over a hot engine = bad).

[t vago]

Originally Posted by 93tracerwagon

I'd like to upgrade our 2007 Dodge/Jeep 3.7 v-6 I believe the original are 2 hole. 4 hole are pretty easy to find but cannot find 12 hole.

You should be able to use the 0280156161 injectors, just fine. You will have to consider, though, that you cannot use the injector clips. That's fine, because the fuel rails are bolted down and the injectors won't be going anywhere.

Originally Posted by ksa8907

how do you find this information? I have searched high and low and i cant find anything about the flow rate of the stock injectors.

What injectors are you looking for? From RockAuto.com, the 2008 Cadillac CTS with the 3.6L engine uses Bosch 0280156300 injectors rated at 246 mL/min, and the 2012 Chevrolet Traverse uses a direct fuel injector. You might see some gains by swapping your CTS's injectors with the 12-hole ones.